TC1 lcr-meter transistor-tester fix - Page 1
Forum section: electronics / testgear

author: zappenduster
author_rank: Newbie
timestamp: June 21, 2018, 07:38:36 pm
content: Hello eevblog forum,here is my TC1 (TC-V2.12k) experience. If your tc1 doesn't switch on anymore check capacitor C11 and C12.I got the meter two weeks ago (18 Euro ebay purchase, shipped from china to germany).I tested about 20 components successfully and then: screen black. I no longer could turn it on.It was not my fault - i surely did not connect a charged capacitor or external voltage to input terminals.Only usb-charging function seemed still be OK: red LED for some time, then turned green.U5 boost-IC of my flawed meter was getting hot; voltage at Cathode of D2 about 15V.With some web-hints i figured out a faulty component: a short circuited C (C11 or C12 - not sure anymore which one; they are connected in parallel).One of them got a 'short' of 120 Ohm. The other's value is 5uF. I replaced both with 100nF and 4,7uF electrolytic 100V-rating. Now the meter works again.Cathode of D2 is now at 37V (47V during usb-charging). This voltage is generated for zener-diode testing.While pcb-inspection i measured some capacitors: C8 = C9 = C14 = C15 = 9 uF. C10 = 118 nFD1 = D2 = D3 = 'SL' marked diodes (schottky-type because U_f ~ 250mV).U1 = 44-pin uC Atmega 324PA ; Y = 16MHz crystalU4 = 8-pin uC STC15L104W for wake-up from sleep / measurement cycle / subsequent automatic power-offU5 = 6-pin boost/step-up IC. Marking AL718 (another forum-post states AL605)U6 = 6-pin charge-ICZD1 = zener-diode 6V8 ; DZ2 6-pin marked V05. Some pcb miss those two elements - maybe earlier layouts...battery = li-ion 3.7V 450mAh ; some tc1 got a much larger battery (2x base area)At this position there would be a picture of my handmade pcb-to-schematic translation together with the actual pcb - but i can't insert them here... You can find them attached at the end of this post.Current consumption is 300..400 mA (On-state) and 0,2mA in Standby/power-off). That means 150mAh per month (0,2mA * 24h * 31 days). So a fully charged battery would be drained after three months of non-use.While measuring the circuit sometimes this happened: Standby current 0,2mA switched to 10mA for 25 seconds. Then it sank to 15 uA and remained there till next (On-)Button pressing.After some trial and error i ended up adding a 33k resistor to the 5V-regulator output (soldered piggyback onto C15). This seems to do the job of triggering the 10mA_for_25s period immediately after shutdown. By that sleep-mode is reached safely.Operational states (duration/current): 25s -> 25s -> sleep25 seconds: On-button was pressed, screen is lit, meter tries to identify connected component. I = 300..400 mA25 seconds: 10 mA current draw after automatic shotdown, screen blackxx seconds: 15 uA sleep-mode till next button pressing / measurement cycleIf i keep my tc1 busy (pressing button repeatedly) sometimes the sequence is 170s-170s-sleep. I don't know what goes on here...IR remot control detection:The ir-indicator (red dot in upper-right corner of screen) is flickering sometimes although input-area is covered up. I added a 100nF capacitor between Ground and Vcc of ir-receiver. But no change, this intermittend behavior is still there...My guess about U4 port-configuration: Pin_1 is configured as interrupt: pressing button wakes device from sleep. Pin_3 switches on U5 boost-ic. Pin 5+6 used as common input to determine desired automatic power-off time (10s/15s/20s/25s - depending on connections P1/P2 <-> Ground/U4_Vcc).About U4 functionality see alsohttps://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg1553608/#msg1553608TC1 manual:www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/?action=dlattach;attach=310740TC1 high-resolution pictures:https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/2225/TC1 review + hr-pics:https://lygte-info.dk/review/ComponentTester%20Multifunction%20Tester%20T1%20UK.htmluC STC15L104W is described/listed here:http://www.stcmcu.com/datasheet/stc/STC-AD-PDF/STC15-English.pdfSome web search brings up T6 labeled models (monochrome display, ir-receiver is placed on screen's right side). T7 looks the same as tc1. At startup it shows a brand/firmware name for a second.Indicated data of tc1-testet components:As lygte-info.dk review states, scr/triacs are partly recognised as resistor or BJT; h_FE values of darlington-transistors with BE-resistors are much too low.To me also capacitor ESR-values seem low: My Peaktech 2063 LCR-meter shows much higher values (it's presumably identical to Extech 380193 meter; component test-frequency can be switched from 120Hz to 1kHz)What do you think of those misrepresentations/discrepancies? Can i just add a fixed offset to displayed capacitor ESR-values?Thank you to eevblog and previous contributors to that matter...zappenduster

author: hydroksyde
author_rank: Newbie
timestamp: June 23, 2018, 04:47:04 am
content: Thanks, mine just arrived with the same issue. Replacing C12 with a 100nF ceramic fixed the problem..

author: zmaxpayne
author_rank: Newbie
timestamp: June 29, 2018, 05:26:13 pm
content: Hi to all.I damaged mine (tc1).I was so stupid to hook on a charged capacitor :-(.So when i press to measure it stays black. Black screen.The loading led is still working.Do you guys think i can fix it?What component could i damaged?Thx.Stefan from Belgium.

author: indman
author_rank: Super Contributor
timestamp: July 01, 2018, 12:31:48 pm
content: Remove DZ1 = with zener-diode 6V8; DZ2 6-pin marked V05. To give power on a tester without remote elements. If the problem remains, then YOU have damaged the ATMega324 processor. His replacement and a new firmware is necessary.

author: cataboier
author_rank: Newbie
timestamp: July 09, 2018, 08:17:13 am
content: Thanks so much !

author: ahmad_hodrob
author_rank: Newbie
timestamp: August 11, 2018, 08:29:21 am
content: dear Sir,kindly note that I have T7 transistor tester that suddenly stopped working upon checking i found that C11 is shorted I replaced it with a 10uf capacitor, know the device is working but it doesn't go to calibration mode when I connect a short wires to it, instead it reads the short wires as a resistors with a value of about 11 Mohm.please I need an advice and if anybody can help me with the software of the unit.

author: flodo
author_rank: Contributor
timestamp: September 11, 2018, 10:10:47 am
content: I made a new firmware for U4 and the standard-firmwarehow toflash it is explainedhereandherethe current versionis v0.2, you can find ithereUnfortunately my tc1 is still drawing 0.11mA at sleep mode - seems to be a bit high.I am not yet sure what the problem is.

author: flodo
author_rank: Contributor
timestamp: September 11, 2018, 01:25:54 pm
content: @zappenduster: how have you measured the drawn current? I wasn't able to do that properly since every resitance in series is preventing power on somehow.

author: Bighouse
author_rank: Newbie
timestamp: September 12, 2018, 07:51:55 pm
content: My TC-1 suddenly only measures a weird cell voltage all the time. Whatever I put in the the thing. Shorting the 3 probe pins also doesn't trigger the autocalibration anymore. Kind of a noob in this diagnosing. I don't read anyone having this specific problem.The value varies somewhat, but it's between those pins all the time.Any thoughts?

author: flodo
author_rank: Contributor
timestamp: September 14, 2018, 10:44:21 am
content: Maybe this helps (thanks to indman for the schematic).I would start by measuring all those components within the yellow marking (especially DZ2).

author: flodo
author_rank: Contributor
timestamp: September 14, 2018, 02:40:35 pm
content: DZ2 is probably the most promising part since you seem to have a positive voltage at socket ② - is the diode still working correctly?You can find a datasheet here:https://www.semtech.com/uploads/documents/srv05-4.pdfYou can get a new one here (at least in Germany):https://www.conrad.de/de/tvs-diode-bourns-cdsot23-srv05-4-sot-23-6-6-v-500-w-1055462.html

author: Bighouse
author_rank: Newbie
timestamp: September 17, 2018, 10:48:38 am
content: I remember having the device plugged in with an (empty) Capacitor for a maybe a few weeks. Could it be that the capacitor got charged up by having it plugged in, and then releasing it's charge damaging my device in the process? I only hear about 'real' dead devices, with black screens when people plug in a charged capacitor. My issue looks somewhat more subtle.Will try to measure. All those tiny spots, hope it'll work.

author: indman
author_rank: Super Contributor
timestamp: September 17, 2018, 02:21:59 pm
content: Quote from: indman on July 01, 2018, 12:31:48 pmBighouse,already I wrote earlier how quickly to define malfunction.

author: flodo
author_rank: Contributor
timestamp: September 17, 2018, 02:32:04 pm
content: Good ideaindman! Yes Bighouse, instead of measuring you can simply remove DZ2 and see if the Tester still shows an voltage.

author: flodo
author_rank: Contributor
timestamp: September 20, 2018, 09:44:26 pm
content: does someone have already dumped the original fw?

author: eliocor
author_rank: Unknown
timestamp: September 20, 2018, 11:14:58 pm
content: Quote from: flodo onTodayat 21:44:26

author: indman
author_rank: Super Contributor
timestamp: September 21, 2018, 07:56:41 am
content: The Chinese original firmware ATMega324 for clones of LCR-TC1,TC6,TC7 are protected from reading of Lock by bits! Don't suffer, it won't turn out to remove them. If only who has available an electronic scalpel and the corresponding equipment for reading of the opened crystal.

author: zappenduster
author_rank: Newbie
timestamp: September 27, 2018, 11:02:44 am
content: @flodo I put a multimeter (Aneng AN8008) in line. I bridged the multimeter while tc1 is in on-state. When tc1 shot down i removed the short and measured about 15uA sleep current.Your 0.11mA Standby seem to be the 0.2mA i measured (range about 0.13 - 0.19 mA). By adding a 33k resistor to the 7805-output i got it to 15uA sleep, see my first post. But i don't know how reliable this is...Here are some notes (which were new to me) for tc1-repairer , gathered by others:DZ2 = TVS Diode Array = SRV05-4 (on some pcb its silk-screened ZD2)U5 = DC-DC controller = SD6271 Step-Up Current Mode PWM Converter. Marking ALxxx (xxx = three digit lot-number)tc1 schematic from azure:https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/?action=dlattach;attach=521336tc1 schematic from indman:https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/?action=dlattach;attach=521411That makes it a lot easier to get a broken tc1 back on track.

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 07, 2018, 06:06:05 pm
content: i bought this TC1 unit with expectation it is the same as M328 variant that i bought and worked charmingly earlier, but now my brother is using it now so i have to buy for myself. it turn out this is different atMega324 with STC15W104 chip, this turn out to be nightmare. and then i found this thread. after back and forth reading this thread i managed to get something from STC-ISP...Quoteif i choose STC15L104W as demonstrated by earlier experimenters, i wont get any report from the chip.the problem when i got this unit is the shorted C11, so i changed with 100nF, no more short, but when battery is applied, lcd turn on white for half a second or so and then random garbage before turned off immediately. pressing start button do nothing. sometime the tester did turned on and firmware on mega324 did start, but its just luck. after reprogramming STC15W104 with frodo's tc1_u4_v0.3.1.hex, now its totally blank. removing and applying battery, there is no more white screen, no start button respond nothing. ah F the STC chip what was that? support us people of China guaranteed powerful home grown business FU so much so for anti disturbance super strong chip.earlier i removed the STC chip and connect Vbat pin to the next pin controlling the boost dcdc chip (AL673 marking), the atmega did start but halted at welcome screen its like waiting for signal on either P3.3/PD2 or P3.2/PD1 i suspect to start measurement. i have to experiment later. i think i will remove the STC chip and glue it to blank space on the pcb so it can wave dick all day long all its like. i need to find a way to start the atmega chip the hard way. or anybody else can help me make program for the STC15W104 chip? i will be gratefull, for now i dont have time to play/install with Keil or whatever. i just want it to work and then move on.btw,1st picture: thermal imaging superimposed when shorted C11 is installed. the SD6271 got hot 73degC as registered by my camera.2nd picture: how i connect the STC15W104 to USB-UART converter. need few experiment though since warning from people to use 3.3V rail, 5V may damage the fucked up super strong STC. it turned out i just use 5V UART and it just worked fine.3rd picture: the fucked up super strong anti disturbance STC15W104 chip made home grown in China, please support it people of China. i really pissed off can you imagine by now?thanks to people directly or indirectly contributed to this thread esp OP zappenduster, frodo and others, but your FW doesnt work with mineand schematics providers indman and azure.edit: added 4th picture with its IO state to PD1/PD2 from my crude test.. and the mega fw wont start by simply toggling PD1 pin, so there must be the right sequence to turn it on

author: prakash_kadri
author_rank: Newbie
timestamp: November 09, 2018, 03:34:10 am
content: @zappenduster, I had same issue with my T7. Replaced C11 and C12 with 100nF 100V and 4.7uF 100V. Now it is working. Thank you very much for sharing the fix.

author: funkervoigt
author_rank: Newbie
timestamp: December 21, 2018, 01:11:18 am
content: Hi !I also have an defective TC1 Tester and followed your fabulous troubleshooting tips here.The unit didn´t startup, i checked the capacitors C11 and C12, and the zener-diode DZ1. They seem to be OK.After that i removed the TVS Array DZ2. Now the Device boots up (display flickers a few times when starting) but shows a cell voltage like in the picture from "bighouse".For my understanding: Is it correct, that after removing DZ1 and DZ2, the ATMega should work normally, otherwise it is damaged (by overvoltage) and needs to be replaced ?Thank You !

author: Attilator
author_rank: Newbie
timestamp: January 04, 2019, 09:33:38 am
content: Hi,I am lucky and got a fully functioning TC-1 unit. My question is about setting the shutdown time to 25sec.I see in the manual that both P1 and P2 need to have ZEROs. Could you please suggest where this ZERO PIN is located? Just want to be safe before soldering.Thanks.

author: amunro
author_rank: Newbie
timestamp: August 17, 2019, 11:25:28 pm
content: I know this is an old thread, but it seems a good thread to append my experiences to! I recently bought two TC1 LCR testers. One was fine, while the other was difficult to turn on, and then it just would not turn on. So just spent the evening removing components and testing them. What I found was similar to others; U5 gets hot. However my issue was a short on the 5v rail, rather than the 35v rail. I was seeing a short of about 9 ohms. Thought it would be a shorted capacitor; not just from this thread, but its a common issue on lots of smt circuits. I could not find anything else hot, which was strange (mind you my room is quite warm where I was working, which does not help). The caps are really small and time consuming to remove and put back so wasted lots of time on that. Anyhow turns out it was the SRV05-4; when removed from the board it had 9 ohms between vcc and ground, and on the pcb, the short had gone. Furthermore, as soon as plugging in the battery the display fires up with the normal startup. Anyhow not wishing to experience failures because of the removal of the V05, I quickly disconnected the battery. V05 (as printed on the chip) are dirt cheap from China in a SOT23-6 package; got 10 of them ordered for £1.80, and they should turn up in 2 or 3 weeks to the UK. I don't mind waiting as it will be handy to have some spares incase of a repeat or incase I destroy one with a charged capacitor!Which brings me back to why was it faulty straight from ebay? I suspect it was a return where someone might have damaged it, and requested a return. Then the seller just stuck it back in stock without checking it. Alternatively the SV05 was just bad?

author: amunro
author_rank: Newbie
timestamp: August 18, 2019, 07:59:57 am
content: Also some of my capacitor parts were different to zappenduster. What I wrote down as I was testing:c8 = c11 = c12 = 5uFc9 = 16nFc10 = 9 uF (slight out 10uF?)c14 = c15 = 10 uFLooking at what spec of 4.7/5uF 0805 capacitors are available, they seem to only go up to 16v. 0805 is 2mm x 1.25mm so that quite an achievement for such a small device. However for c11/c12 I measured 32v (and circuit diagrams above say 35v), so thats way under specified. Thus ordered some 50v 10uF, similar to what zappenduster mentioned, and will swap them out for 1 x 10uF, and add a decoupler of 100nF with 50V spec.I know I am rambling here, but this thread was really useful to fix my unit, and hopefully my experiences will help others.

author: amunro
author_rank: Newbie
timestamp: September 25, 2019, 07:22:49 am
content: My saga continues. The SV05s turned up from the slow boat from China (£1 for 10 of them). Soldered it in and still have an issue. Seems there is still a short on the 5V rail to ground (tested with an ohm meter), but not a sufficient short to pull the 5v down and to cause U5 to get hot. After some fault finding, I lifted pin 27 (avcc) of the atmega off the board and the short went away. So looks like the atmega324 is at fault. Ordered some more and will wait for them to turn up from China ($1.40 each).In the meantime decided to learn about atmega flashing as I am going to need to flash the new atmega when it arrives. Soldered some pins onto the LCR-TC1 for the ISP port. Bought a USBASP programmer off ebay for not much money, installed avrdude (I use ubuntu so just install it via apt). Disconnect the LCR-TC1 battery and connect up the USBASP; it finds the atmega fine; tried to read the eeprom and flash; avrdude reads it and then reports the file is zero bytes (don't remember the exact message). Seems the lock bits are set. Did some reading up on lock and fuse bits (or bytes); understand these now. Decided to erase the atmega via avrdude; can't read the eeprom/flash anyway, so might as well. Then try and flash some new firmware. Discovered indman's LCR archives on yadi.sk and downloaded some firmware, which works (but the chip is broke so can't fully test); both the Markus Reschke firmware and the original firmware he posted (9/16/2019) flash and boot fine. Many thanks to indman for collating and making available these firmwares.This unit I got off ebay, but was faulty on arrival so I got a refund on it. Thus its sitting round doing nothing so figured its worth fixing and experimenting with. Even trying different firmware on it. I bought another to replace this faulty one so its not as if I am desperate to get it fixed.Again another ramble, but hopefully my hard earned time learning all this will be useful to someone!

author: amunro
author_rank: Newbie
timestamp: October 10, 2019, 06:59:25 am
content: Posting an update. So I received some atmegas from China which look like fakes. One of them does not have a circle near pin 1 which is really suspect. Anyhow, ordered one locally from RS Components in the UK, which was pretty reasonable and had free shipping (if I had known that I would have ordered from them). This flashes fine using a USBASP (with the latest firmware); you need to use -B 5 for the slower rate comms with avrdude. I will try the Chinese atmegas with a crystal at some point just to confirm they are fake; if they do work they are not new from Atmel/Microchip! As I was testing the fake atmegas, I used a break out board and just soldered pins 1 thru to 6 to allow the ISP flashing. A nice diagram herehttps://www.kanda.com/avr-isp-circuits.htmlof what is required (need a 100nF capacitor and a 10k resistor on the board). Once I flashed the Rs Components atmega I then undersoldered it from the breakout board and onto TC1. Low and behold we have a working TC1.So to summarize, SV05 had a short pulling the 5V line down; replaced that. Still had a short, but not as bad. I then had the issue as shown in the photo by Bighouse, although my issue was with pins 1 and 2. Lifted pin 27 (AVCC) of the atmega off the board and short gone. Replaced both of these components. Thus I would say if you have the issue as shown with Bighouse you might need a new atmega. Used indman's LCR-TC1 original firmware on yadi.sk (date 9/16/2019).Hope my hard earned effort helps someone! Was pulling my hair out with the fake atmegas!Attached a photo of the breakout board patched into a 6 to 10 pin ISP adapter. 10k resistor on the top and 100nF capacitor is a smd soldered on the bottom of the board.

author: capitainekurck
author_rank: Contributor
timestamp: November 13, 2019, 03:36:56 pm
content: Hello allI new on this forum.I bought one of there tester on ebay.I receive it today it work 5 or 10 minutes and it fail. i was trying to check some resistor and led to test it (not capacitors) and suddenly it stop to work. it don't turn on any more. The battery is full load. when i push the button to power it on, the screen become white ( it normally black when it power off) and it turn black few seconds after.Is it the same problem as yours or for you the display stay black ?regardsL.S.

author: quinhomvs
author_rank: Newbie
timestamp: December 01, 2019, 02:50:52 pm
content: Hi , I am from Brazil , my TC1 multtest , reads the components , but when there is no component connected shows the measurement as in the attached figure, someone already had a similar error .Translate.

author: madires
author_rank: Super Contributor
timestamp: December 01, 2019, 03:35:45 pm
content: That means there's a small current flowing between the probe pins, possibly caused by the SRV05-4.

author: Del
author_rank: Newbie
timestamp: December 27, 2019, 03:58:27 pm
content: Hello. I'm sorry, I'm using a translator . Can you share the compiled hex and EEP firmware ? I wanted to update the firmware but broke the tester . Compiled the firmware from MARKUS, the device is working, but there are no functions IR and ZENER diode , . Thank you in advance !

author: madires
author_rank: Super Contributor
timestamp: December 27, 2019, 05:28:15 pm
content: If you like to run the m-firmware please use the settings for the TC-1 listed in the Clones file.

author: Del
author_rank: Newbie
timestamp: December 27, 2019, 05:37:03 pm
content: I can't do it . Errors . 324pa processor

author: madires
author_rank: Super Contributor
timestamp: December 27, 2019, 05:48:30 pm
content: Have you set the correct MCU model in the Makefile?

author: Del
author_rank: Newbie
timestamp: December 27, 2019, 06:10:26 pm
content: Yes, of course, I was able to collect a simple firmware . The problem is to create config.h . Might not have version 1.34 , but I have tried all 1.34-1.38 . Sorry, but for me it is not quite clear, I do not really understand English , and I work with hardware and not the software part.

author: Del
author_rank: Newbie
timestamp: December 27, 2019, 06:16:59 pm
content: Could you at least share the config.h and Makefile and specify version 1.3 x Markus ?

author: madires
author_rank: Super Contributor
timestamp: December 27, 2019, 06:19:12 pm
content: There's a Russian forum:https://vrtp.ru/index.php?showtopic=16451.

author: Del
author_rank: Newbie
timestamp: December 28, 2019, 03:57:51 pm
content: What and in what file should be corrected to freeze occur only once, after pressing the button ? And then the tester should be turned off . And at me the screen is displaced on nekkolko pixels up and to the left, that is it is necessary to shift it down and to the right - as it to consult.

author: madires
author_rank: Super Contributor
timestamp: December 28, 2019, 04:12:14 pm
content: You can use LCD_OFFSET_X and LCD_OFFSET_Y to adjust the display's offset. What do you mean by "freeze"?

author: Del
author_rank: Newbie
timestamp: December 28, 2019, 04:32:16 pm
content: Quote from: madires on December 28, 2019, 04:12:14 pmSorry, I'm using a translator. freezing is wrong , I meant a single measurement . insert the component into the pad, press the button, see the readings and after 10-20 seconds the device will turn off itself .LCD_OFFSET_X and LCD_OFFSET_Y to adjust the display's offset - this in what file to edit ?

author: madires
author_rank: Super Contributor
timestamp: December 28, 2019, 10:02:38 pm
content: LCD_OFFSET_X and LCD_OFFSET_Y are set in the display section in config_644.h (ATmega 324/644/1284). For a single measurement you would have to modify main() since there's no setting for that.

author: Del
author_rank: Newbie
timestamp: December 30, 2019, 06:45:03 am
content: Quote from: madires on December 28, 2019, 10:02:38 pmSUPER ! everything worked out ! thanksQuote from: madires on December 28, 2019, 10:02:38 pmThis setting is in flash tc1_u4_v0.3.1.hex ?

author: madires
author_rank: Super Contributor
timestamp: December 30, 2019, 10:28:35 am
content: I've meant main() in m-firmware's main.c.

author: Del
author_rank: Newbie
timestamp: December 30, 2019, 12:15:25 pm
content: in main.c. -- if (MissedParts >= CYCLE_MAX)which in config.h#define CYCLE_DELAY 10000#define CYCLE_MAX 0Super ! now the device turns off after 10 seconds, after the 1st measurement

author: Dronhom
author_rank: Newbie
timestamp: January 27, 2020, 06:23:26 am
content: Had a previously mentioned problem when the tester always shows around 5 V ghost voltage between 1-2 or 1-3, and the problem couldn't be solved by re-calibration etc. Based on advice here, I took off zener diodes DZ1 and DZ2 - and the problem disappeared! After that I checked DZ1 and found it in good working condition, but DZ2 was short. Thanks to all contributors to this topic for useful information.

author: klausES
author_rank: Regular Contributor
timestamp: March 01, 2020, 01:24:02 pm
content: Is it possible to deactivate the automatic switch-off P1-P2 for 15, 20, 25 seconds (25 seconds default) with this tester ?I would prefer to switch it off manually with the button.Or at least shutdown on e.g. 60 seconds ?

author: madires
author_rank: Super Contributor
timestamp: March 01, 2020, 02:42:33 pm
content: Yes, by reprogramming U4 and switching to k or m-firmware.

author: klausES
author_rank: Regular Contributor
timestamp: March 01, 2020, 02:50:33 pm
content: OK thank you.To do this, I would first have to deal intensively with this topic.Let's see how much time I can and must invest.

author: Von Wuellmann
author_rank: Newbie
timestamp: March 04, 2020, 08:00:29 pm
content: Hi!I also have a Longruner brand TC1 that has the same problem, this only measures a cell voltage, this 5.04v case Whatever I put in the the thing. Nor can I have it enter calibration mode.Looking at this same post about the answers, I managed to verify the DZ1 and DZ2 and these work correctly, so I had come to the conclusion that I need to change the atmega324pa. I am from Argentina and it is difficult to get this microcontroller in the market, can there be someone else I can replace? also another query, if I do get to buy 324 fro

author: Geert
author_rank: Newbie
timestamp: March 04, 2020, 09:02:54 pm
content: Is there a newer firmware available for the TC1 ?My tester has version 2.12k

author: madires
author_rank: Super Contributor
timestamp: March 05, 2020, 09:36:42 am
content: Quote from: Von Wuellmann on March 04, 2020, 08:00:29 pmHave you tried with DZ1 and DZ2 removed?

author: madires
author_rank: Super Contributor
timestamp: March 05, 2020, 09:45:17 am
content: Quote from: Geert on March 04, 2020, 09:02:54 pmThat's a modified k-firmware (modified by the manufacturer). I don't know if there's a newer version, but I'd recommend to upgrade to the OSHW firmware (k or m). And don't forget to reprogram U4 (https://github.com/atar-axis/tc1-u4) or replace it with a small circuit (https://github.com/madires/Transistortester-Warehouse/blob/master/Hardware/TC1-Mod.kicad.tgz).

author: ceut
author_rank: Regular Contributor
timestamp: March 05, 2020, 04:55:00 pm
content: Quote from: Mechatrommer on October 07, 2018, 06:06:05 pmHello,I have exactly the same problem on my brand new LCR TC1 (DOA).No power on, only charging, and 22mA of continous current draining from the battery .There is no voltage on the switch when not pushed (pin1 of U4), and it seems that it's U4 who drains that 22mA, so I think that U4 is blank or something like that.But don't know how to flash it...No problem on capacitors C11/12 but I have changed them to a 15µF/100VNo problem on diode array, neither on zener.Someone has succeed to fix similar problem ?Thanks !

author: ceut
author_rank: Regular Contributor
timestamp: March 05, 2020, 07:12:27 pm
content: So with only the U4 with only the power pin only on it (PIN2 Vcc and PIN4 GND), I have my "famous" 22mA continous draining.I don't know why they use a MCU for power managing but it seems to be a bad MCU.Also I don't know how to bypass this to power on all.I have tried to apply +5V on the Atmel and I have the boot logo on screen, but nothing else, seems to wait for something and I think it's a link with this bad MCU.

author: ceut
author_rank: Regular Contributor
timestamp: March 06, 2020, 07:20:07 pm
content: I have reflashed the STC with the 0.31 hex and a modded USB serial adapter: no more 22mA draining from it, and it starts when press switch, but freeze on the boot logo.I think I have to find another Atmel firmware to solve my problem.So it was really a Dead On Arrival: the STC was flashed with something corrupted or wrong flash.(After emailing and uploaded a video for them, the store where I bought it send me a new one, but wait again for about 3 weeks).

author: ceut
author_rank: Regular Contributor
timestamp: March 06, 2020, 09:16:08 pm
content: Final words from me: I have flashed the Markus 1.34, and it's working, but I'm not a big fan of itI think I will not use it, and waits for the new one.Hope that someone will find and post the "famous" original STC firmware then we can put the original graphical firmware

author: madires
author_rank: Super Contributor
timestamp: March 07, 2020, 02:26:52 pm
content: https://yadi.sk/d/yW8xa5NJgUo5z/LCR%20%D0%A2%D0%A1-1/Firmware/Original, but I don't know if it will run with the alternative U4 firmware. BTW, the "original" tester firmware is a modified k-firmware with more graphics and less functions. The only additional feature is the IR decoder supporting just one protocol (the m-firmware does about 15). It's a trade-off between fancy graphics and features.

author: ceut
author_rank: Regular Contributor
timestamp: March 08, 2020, 12:57:33 am
content: Quote from: madires on March 07, 2020, 02:26:52 pmHello,Yes, I have tried this one, and in fact it's the original graphical firmware for the Atmel 324pa: it starts but freeze on boot logo with the alternative U4 firmware - I have not found the original U4 fw, it seems to be keep securely somewhereFor the m-firmware, it is good, butfor menot very user-friendlyI have an old LCR T4 which I found better (I have put the latest fw fromwww.mikrocontroller.net).Will wait for the new one and hope that it will work(so I will keep this one for spare part)

author: ceut
author_rank: Regular Contributor
timestamp: March 16, 2020, 03:51:04 pm
content: Received the new one today, shipping was fast, despite of corona virus !The new one works flawlessly.A difference with the previous one: the battery was at about 60% and it has directly booted when I have pressed the button.Will try to understand what U4 really tells to the Atmel for unlocking the boot of it.The color screen is very readable, I like it.

author: cuistots
author_rank: Contributor
timestamp: April 02, 2020, 05:15:08 pm
content: hi i have a ts7h wich a problem, could you tell me for repair it.lot of thanks

author: madires
author_rank: Super Contributor
timestamp: April 02, 2020, 05:21:16 pm
content: I'd suggest to check the power supply circuitry first.

author: cuistots
author_rank: Contributor
timestamp: April 02, 2020, 05:42:20 pm
content: could you tell wich ref to verify ?

author: madires
author_rank: Super Contributor
timestamp: April 02, 2020, 05:53:57 pm
content: U5 should be a 5V voltage regulator. Check in and out.

author: cuistots
author_rank: Contributor
timestamp: April 02, 2020, 06:07:36 pm
content: u5 is good when a usb is connected 6.35v in and 5v out.

author: madires
author_rank: Super Contributor
timestamp: April 02, 2020, 06:19:19 pm
content: Does display show weird stuff when USB is connected?

author: cuistots
author_rank: Contributor
timestamp: April 02, 2020, 06:22:06 pm
content: no it's the same of photo.

author: madires
author_rank: Super Contributor
timestamp: April 02, 2020, 06:39:46 pm
content: The next step is to check the signal lines for the display. Any bad solder joints? If you have a scope also check the SPI signals.

author: cuistots
author_rank: Contributor
timestamp: April 02, 2020, 07:35:53 pm
content: no bad solder joints.and i haven't a scope.

author: madires
author_rank: Super Contributor
timestamp: April 03, 2020, 09:18:27 am
content: In that case you could try another display. IIRC, it's a ST7735.

author: cuistots
author_rank: Contributor
timestamp: April 03, 2020, 10:00:47 am
content: Here is the reference of the lcd display, I will try to uncloud it to see its driver

author: cuistots
author_rank: Contributor
timestamp: April 03, 2020, 10:18:48 am
content: it's exactly my problem:https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg2168986/#msg2168986

author: madires
author_rank: Super Contributor
timestamp: April 03, 2020, 01:07:48 pm
content: Then give it a try and add the two MLCCs.

author: cuistots
author_rank: Contributor
timestamp: April 05, 2020, 11:13:46 am
content: the mlcc is already on the board.i don't understand the problem

author: madires
author_rank: Super Contributor
timestamp: April 05, 2020, 12:13:26 pm
content: Power the display module with 5V and check the output of the 3.3V regulator.

author: indman
author_rank: Super Contributor
timestamp: April 05, 2020, 12:49:40 pm
content: Quote from: cuistots on April 05, 2020, 11:13:46 amIf 3.3V regulator normaly works - with a very high probability, the source of this problem may be a malfunction of the U1 level converter chipWhat is the marking on her case?

author: cuistots
author_rank: Contributor
timestamp: April 05, 2020, 01:23:11 pm
content: this u1

author: cuistots
author_rank: Contributor
timestamp: April 05, 2020, 01:39:57 pm
content: the 3.3V regulator normaly works.

author: indman
author_rank: Super Contributor
timestamp: April 05, 2020, 01:54:36 pm
content: U1- the 74HC573; 74HCT573 is an 8-bit D-type transparent latch with 3-state outputsTry replacing this chip. Another option is to remove this chip and connect the ATMega outputs directly to the display lines through 10kΩ resistors.They are already on the display board. But this option is only at your own peril and risk.

author: Krafte
author_rank: Newbie
timestamp: April 19, 2020, 03:13:09 pm
content: Yesterday, I got a shiny new TC-1 directly from ChinaI successfully got a 1.38m firmware running and testing components seems to work.However, the LCD keeps flickering and the device turns randomly off. Also, the menu is not accessible by double pressing the button.I think the reason is the stock firmware on U4. I tried to replace it with the custom one. But it seems the chip is not responding to the programmer.I tried everything I could imagine , different PCs different uart adapter, all combinations of power on cycles for U4, double and triple checking the connections and pinouts, but nothing helped.Anybody with same experiences? Any advice apart from replacing U4 by the proposed circuit of Markus?The only thing that's a little strange are markings on the chip. It is "STC 16L104W".UPDATE:I got the chip to respond to me using my RPi 3 andstcgal(I strongly recommend this tool). It reported as STC15L104W.However, flashing was not possible -> it always stopped while switching baud rates.Finally with baud rate 1200 it was flashing, slowly but successfully

author: Kamlakkannan
author_rank: Newbie
timestamp: August 15, 2020, 10:11:02 am
content: Hey, I just got the lcr t7 from China yesterday(after almost 3 months). It worked for sometime then it just displayed a white blank screen. After sometime it worked, but then again it displayed just white blank screen. This process repeated and now I am stuck with something that just displays a white screen. I checked the capacitors they aren’t short. The battery is good and I don’t know what to do next, so can you please help me.

author: Kamlakkannan
author_rank: Newbie
timestamp: August 15, 2020, 10:13:20 am
content: And again after sometime it started working.

author: Kamlakkannan
author_rank: Newbie
timestamp: August 15, 2020, 10:32:39 am
content: And now again just a white screen

author: alfagulf
author_rank: Newbie
timestamp: October 23, 2020, 04:18:59 pm
content: I would like to add my experience with the TC1 that I bought from Banggood as a replacement for another unit which I zapped by connecting a charged high voltage capacitor by mistake.The new unit arrived faulty.The unit did not power up, so I assumed the battery is dead and need to be recharged, which I did, but still pressing the start button did nothing.I contacted them and they offered a refund which I accepted.However I suspected the problem is around U4 (STC15W104) since it manages the start button and sends a signal to the boost converter U5 to start.I noticed that pin 3 (P3.5) is not going HIGH when I press the button which of course the reason why it is not powering up.I first reprogrammed U4 with the alternative firmwarehttps://github.com/atar-axis/tc1-u4, but that did not change any thing.I then replaced U4 with the one I had in my first faulty unit. I started to have some intermittent success where the unit will power up sometimes and shuts down unexpectedly.I then did more testing around the push button when I noticed C13 a debounce capacitor that had its resistance rather low (around 30K).I removed it and the tester worked like a charm.However I then replaced it with a good 100nF capacitor to keep the debounce function.The U4 which I remove (I suspected to be faulty) turned out not faulty, I found out that by reprogramming it to output a 1Hz pulse on all ports which it did.So I guess the problem for me was the faulty ceramic C13 capacitor.I hope this information might help some of you.Thanks

author: dvd4me
author_rank: Regular Contributor
timestamp: November 05, 2020, 03:01:00 am
content: Hello,I just got today the TC1 from Bangood and it was defective, not turning on.I found this post and after measuring the caps on the battery or the +3.7V rail, nothing wrong.Plugging the battery made the screen to briefly turn on.At the power on button, I noticed there was no voltage on the button contacts, just a very low 0.3V.Putting 5V at the output of the U3 regulator made the screen to turn on but the boot stops at the daniu logo.I just saw the post before me and noticed the C13 warning it might be leaky.Removed the C13 and now it powers up at the insertion of the battery, yey!Measuring the voltage at the power button is 3.8V ! So that's the normal voltage it should be on a normal tester.I just put the cover back and that's it for now.Now it works, see the second picture.

author: shved
author_rank: Regular Contributor
timestamp: November 08, 2020, 03:11:37 pm
content: A friend gave me TC1 with bulged battery and some damage.I've cleaned it up and swapped in used samsung mobile phone battery. Changed c13 as a precaution. Everything works, as far as i can check. But stand by draw is around 20mA. Is that normal? Do i need to add a a battery cutoff switch? I have several LC, RLC, ESR, ... meters, but with external power(no battery only USB or 12v PSU), so i plan to use it for away jobs witch are quite infrequent.My point is: the tester will be always "flat" when i grab it.Any advise?

author: madires
author_rank: Super Contributor
timestamp: November 08, 2020, 05:02:15 pm
content: That stand-by current is much too high. A classic power switch would be a simple fix. If you want to run one of the OSHW firmwares (k or m-firmware) you can replace U4 with a small circuit with two BJTs and the stand-by current will be about 5µA. With U4 the current should be around 0.2mA.

author: shved
author_rank: Regular Contributor
timestamp: November 08, 2020, 11:19:21 pm
content: Thanks madires.I think I've fixed it. Now the stand-by current is around 0.2mA.The problem was in the caps C6 & C7. The caps turned in to resistors and loaded the battery and 5V rail through the diodes. I don't quite know where the energy went, the caps didn't heat-up. I've tracked them down because 5V rail read too low(~4,5V) and battery check on boot showed the wrong voltage. To isolate the issue I've disconnected the diodes in turns, when 5V came back clean, I knew immediately to check the caps!Also, the factory where they assemble the bloody things uses some reactive flux and doesn't clean it off. I strongly suspect that it's a factor, seen that before.Anyway, anyone who has excessive stand-by current(around 20mA) check the caps C6 and C7! And I advise to wash the flux off the boards.

author: a_kiler
author_rank: Newbie
timestamp: November 13, 2020, 02:56:41 pm
content: Hi, everyone.Like most of us here I unfortunately damaged my brand new T7-H. Capacitor dead screen... sounds familiar?Thx to advice:@zappenduster: I bought 10uF capacitor; (didn't use it)@indman: I removed DZ1 and DZ2 and... success, the screen is on. But sth else strange (for me) happend.Tester works "like new".Calibration: passCapacitor: passLED: passIR: passEven removed DZ2 - zener diode: passSo if DZ2 is ok, DZ1 must be failure.Oh, BTW - my is tester is a little bit different (pictures included) and DZ2 is 6V8C, DZ1 is V5L. I hope datasheet ic correct?How can I examine DZ1?@zappenduster said earlier:QuoteIs it possible the tester will work normally without DZ1 DZ2 or should I expect the unexpected.

author: madires
author_rank: Super Contributor
timestamp: November 13, 2020, 03:16:07 pm
content: Yep, the tester works also fine without the input protection (DZ1 and DZ2). DZ1 should be a 6.8V TVS (not shorted = OK).

author: belzrebuth
author_rank: Frequent Contributor
timestamp: December 18, 2020, 02:32:29 pm
content: I did the charged capacitor trick on mine so now it's dead..DZ2 is certainly faulty and I've also found some shorted ceramics in there as well.In total I've removed capacitors C14,C15,C24,C21,C23.I haven't yet measured DZ1 but I've removed it for good measure.I've also tested the 5V regulator out of circuit and it's working.The problem is that the meter only boots when I'm applying 5V externally in the place of the 5V reg output.When it boots it shows there's a DC source between terminal 2 and 3.When connected to a USB plug only the red charging LED lights up but the meter is dead.I think I'm probably having a problem with other stuff as well like the DC-DC section or else.Since the MCU is probably working what might be going on with the power stuff?How did I manage to save the MCU and I have a problem in the PSU section.There is no input voltage to the 5V regulator when I'm connecting the USB plug so no wonder the meter is dead.What could be the culprit here?Would it be fixable?

author: madires
author_rank: Super Contributor
timestamp: December 18, 2020, 03:52:57 pm
content: Presumably the ATmega's pins used for terminals #2 and #3 are shot and maybe also the control MCU U4. You can check the DC/DC converter by enabling it manually.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: December 18, 2020, 05:12:00 pm
content: Thanks for your reply madires.Really appreciate your help.I get about 21.5V where I should be getting about 37.. (D2)How should I enable the DC converter manually?!I noticed that if I connect my bench PSU to the battery terminals providing 3.7V if I press the button I get about 0.35A current draw and then after a short period of time almost no current draw(0.9mA) or so.Forgot to mention that I get about 3.4V at the 5V regulator input and 1.7V at it's output.The regulator input and the 35V rail which is 21.5 maybe tell that the DC-DC converter might be faulty?!I also get about 25ohms between the 5V rail and ground which seems low but then again the meter boots when I give it 5V and it's current draw is not excessive.

author: madires
author_rank: Super Contributor
timestamp: December 18, 2020, 05:38:06 pm
content: If the boost controller is an AL693 pull up pin 4 (to the battery's voltage). That pin is connected to a pull-down resistor and pin 3 of U4.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: December 18, 2020, 06:56:54 pm
content: The marking of U5 is AL715..

author: madires
author_rank: Super Contributor
timestamp: December 18, 2020, 07:22:11 pm
content: No idea about that one, but I'd guess it's quite similar.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: December 18, 2020, 08:24:46 pm
content: Nothing changed when I pulled the pin4 to 3.7V.Same input to the regulator.If nothing else down the line is preventing the 9 or so volts to appear maybe the DC/DC is bad.Maybe I should just buy this IC and replace it, as long as it exists somewhere which I'm not sure of.Seems like a non-standard part available in China only.If I power the thing with 5V directly shouldn't it measure components though?I mean if my MCU is also bad (which btw is an ATMEGA 644 not 324) I could just buy a new meter and discard this..Are the capacitors I've removed critical to the operation when powered directly from 5V?

author: indman
author_rank: Super Contributor
timestamp: December 19, 2020, 07:16:20 am
content: Quote from: belzrebuth on December 18, 2020, 05:12:00 pmIt is very likely that your MCU is damaged. Take a multimeter and check the resistance of the PA0-PA3 test ports against + 5V and the ground. You can also check the resistance of pin 4 (VCC) to ground.AL619 (AL715, AL718) this is the marking of the SD6271 chip

author: belzrebuth
author_rank: Frequent Contributor
timestamp: December 19, 2020, 10:53:39 am
content: Vcc to Ground is around 25ohms.I mentioned it before and it seems weird that it's too low but when I power the thing directly with 5V its current consumption is within spec at around 350mA.PA0 to Vcc 560kPA1 to Vcc around 20οhmsPA2 to Vcc around 112ohmsPA3 to Vcc 2.2kI wonder why they used a 644 in my revision instead of a 324 which is almost triple the price. PCB version is 2.0.

author: indman
author_rank: Super Contributor
timestamp: December 19, 2020, 11:42:29 am
content: belzrebuthFrom + 5V, the serviceable tester consumes from 24.6mA to 44mA. You have a defective processor, you need to replace it. It is not difficult if you have the skills to solder such things. Better to buy the same ATMega644. Chinese friends very often install those parts that are currently in stock. In terms of cost, the difference between chinese 324 and 644 is very small. They earn more due to the large number of devices sold.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: December 19, 2020, 01:58:08 pm
content: Ah okay..thanks:)I thought the current draw was normal all this timeI'll replace the MCU and post back.

author: shved
author_rank: Regular Contributor
timestamp: December 19, 2020, 03:21:31 pm
content: belzrebuth, I've also had excessive power draw. Double check the caps, esp. C6 & C7. Also check for corrosive flux. Give a quick read to the rest of the thread.

author: bob91343
author_rank: Super Contributor
timestamp: December 20, 2020, 07:34:02 pm
content: My unit works okay but the display is bad. It displays data as expected but the screen has become hard to read. I can change viewing angle for some improvement but still it's bad. It's an early monochrome.I bought another but want to fix this one, as it seems more accurate.

author: shved
author_rank: Regular Contributor
timestamp: December 20, 2020, 08:13:11 pm
content: If you have a mono lcd panel - that's a different model.Most designs using those kind of displays have a contrast POT or a set of resistors witch are responsible for contrast. Check for all of those, + check for panel damage + check for corrosive flux damage.If you indeed have a different model - give this thread a quick read and try to find threads and schematics for your specific or a similar unit.

author: vk3ohm
author_rank: Newbie
timestamp: December 23, 2020, 03:40:34 am
content: Does anybody have a document that explains the principle of operation of these, or similar, devices? I would love to give a presentation to my radio club about how they work, but I've been unable to find any information anywhere.

author: ledtester
author_rank: Super Contributor
timestamp: December 23, 2020, 05:37:02 am
content: Quote from: vk3ohm on December 23, 2020, 03:40:34 amThe site for the project:https://www.mikrocontroller.net/articles/AVR_TransistortesterGo to the Downloads section and get the manual in the language of your choice, e.g.:https://github.com/svn2github/transistortester/tree/master/Doku/tags/english/ttester_eng112k.pdf

author: ledtester
author_rank: Super Contributor
timestamp: December 23, 2020, 08:35:43 am
content: Should add that this is the main eevblog forum thread for these devices:https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/

author: madires
author_rank: Super Contributor
timestamp: December 23, 2020, 10:33:45 am
content: Quote from: ledtester on December 23, 2020, 05:37:02 amThat mirror is obsolete. Please usehttps://github.com/madires/Transistortester-Warehouse.

author: billy_gr
author_rank: Newbie
timestamp: January 09, 2021, 03:13:56 pm
content: Hi,Measured a cap without discharging it and now i got a T7 that measures a cell voltage between pins 1 and 2Removed both the DZ1 DZ2 but the issue remains. Should i assume that the ATmega is toasted ?Thanks in advance

author: madires
author_rank: Super Contributor
timestamp: January 09, 2021, 03:32:15 pm
content: Yep, it's toast. You can replace the ATmega or buy a new tester, whatever is simpler or cheaper for you.

author: billy_gr
author_rank: Newbie
timestamp: January 09, 2021, 05:08:20 pm
content: Quote from: madires on January 09, 2021, 03:32:15 pmThank you !!!

author: speedsterharry
author_rank: Newbie
timestamp: April 09, 2021, 12:43:00 pm
content: Hi all, I'm new to the forum.I found this thread thanks to the amazing power of search engines, and was glad to make my TC1 work again (it was only detecting a 5V cell whatever what was connected to the leads). The SRV05 was dead, after removal the TC1 worked like before.What kind of problem will the lack of ZD2 mean to my TC1 tester ? I don't want to fry it for good !!!Thanks, the amount of good info available here is FANTASTIC !EDIT: I'd like to upgrade my TC1 firmware. Does anyone in France, preferably near Lyon who does that kind of service ? I'm about to get 2 new TC1 just for spares and would like to have them upgraded as well when I get them. I don't want to do it myself, I don't have the tools nor expertise to do that (and don't want)Or maybe one of the developers sends the TC1 with latest firmware ?

author: madires
author_rank: Super Contributor
timestamp: April 09, 2021, 01:19:43 pm
content: ZD2 (SRV05) is a weak over-voltage protection. The tester works also fine without it, but make sure that you always discharge capacitors before connecting to the tester.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: June 07, 2021, 11:57:25 pm
content: Is there a programming header on the TC-1 or should I directly attach wires to the MCU?I destroyed mine with a charged capacitor and I replaced the atmega but I now need to re-upload the firmware.With an older tester I needed to solder wires directly to the 328p in order to update it.

author: madires
author_rank: Super Contributor
timestamp: June 08, 2021, 09:18:35 am
content: You just need to solder an ISP header (unpopulated footprint at the top).

author: belzrebuth
author_rank: Frequent Contributor
timestamp: June 08, 2021, 11:14:23 am
content: Thanks madires.Do you maybe have an avrdude command for the atmega 644?I'm thinking of using the m-firmware.I don't know what fuse settings I need to set on the ATmega 644.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: June 08, 2021, 12:28:09 pm
content: Here are the commands I've gone with; fuses set as follows:avrdude -c usbtiny -p m644 -U lfuse:w:0xff:m -U hfuse:w:0xd9:m -U efuse:w:0xfc:mavrdude -c usbtiny -p m644 -U flash:w:ComponentTester-TC1.HEXavrdude -c usbtiny -p m644 -U eeprom:w:ComponentTester-TC1_eeprom.HEXI think I've managed to upload the firmware fine since I got a "Bye!" on the LCD.I then powered the unit with 3.7V on the battery pins but the tester still doesn't work.The LCD just flashes in white.I think there's something wrong with my "U4" maybe.I tried reprogramming that as well but my chip is scratched down and I can't see the markings on top.I've set various ICs as DUT but no configuaration recognises it..I've gone with STC15W104, STC15L104, STC15L104W, STC15W104 so far..My FTDI adapter outputs a VCC of 3.56V instead of 3.3V would this be the fault maybe??

author: madires
author_rank: Super Contributor
timestamp: June 08, 2021, 12:44:08 pm
content: You can run "make upload" after setting the programmer in the Makefile. And for the fuses it's "make fuses". Regarding U4 you can alternatively replace U4 with a simple two-transistor circuit (https://github.com/madires/Transistortester-Warehouse/blob/master/Hardware/TC1-Mod.kicad.tgz) which also has a lower quiescent current.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: June 08, 2021, 12:48:38 pm
content: The STC-ISP managed to recognise the IC as STC15L104W but I still can't get it to upload the firmware.I have my 6V8 diode removed from circuit while the DZ2 is installed.Can this prevent the tester from working.I only have a 6v8 zener in a thru hole package.Can I install this one?Does it need a high wattage (1W or so) or any 6V8 diode will work?Sorry for all these questions madires, I really appreciate your help.edit: I can't even re-recognise the IC when I try to "check MCU" from the STC software.It did it once and I can't make it to repeat it.So no wonder it can't upload the .hex file.I need to power the DUT under a certain timing frame or something?edit2:To define what my problem is:If I power the tester with 3.7V from my bench supply it starts up and measures components fine.Power consumption is around 240mA when this is happening which I think is a bit excessive.So I let cycle thru "Probing.." around 3 times and then it displays "Bye" and shuts off.If I press the button I get about 200mA current consumption again but all I get is a white screen and then the tester shuts off.What could be causing this behavior?I need to mention that I put diode D0 backwards once I removed it to check it.I powered up the unit one or two times with that diode placed backwards, I hope I haven't managed to destroy my 2nd atmega.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: June 08, 2021, 04:52:02 pm
content: @madiresDo you have a picture or something of your TC-1 U4 replacement mod?I did download it but it's kicad files which can't be opened with Eagle and I can't open it with Kicad either cause there are some libraries or footprints missing as it says.I think I'm going to remove U4 as I can't seem to be able to program it or even check its status.

author: madires
author_rank: Super Contributor
timestamp: June 08, 2021, 06:21:22 pm
content: The Zener/TVS plus DZ2 are a weak overvoltage protection and can be removed without any problem. DZ2 is often damaged in case of a charged cap. 240 mA are much too high. So there's some bad component. The TC-1 mod archive includes three images.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: June 08, 2021, 06:35:50 pm
content: I quickly bodged your replacement circuit in a small piece of proto and it workedCurrent consumption is now 200mA or so when it's on, I find it a bit high as well.But it also works with a semi-discharged battery so I guess it's okay now?!What a typical current draw should be if external power is applied at the battery terminals?

author: madires
author_rank: Super Contributor
timestamp: June 08, 2021, 07:01:44 pm
content: I'm not sure about the exact current draw of the TC-1 since the boost converter also creates the 40+ V for the Zener check. OP zappenduster measured 300-400 mA which are quite high. The standard circuit needs about 20mA @ 5V on average. Add the backlight, the Zener test voltage and a possibly low efficiency boost converter.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: June 08, 2021, 07:05:17 pm
content: I could try applying 5V at the output of the 5V regulator and measure the current draw at that rail to check if it's within this figure (20mA) or so.Another thing I wanted to ask if it's normal for the tester to repeat a component test for 5 retries instead of just freezing at the component measurements.With a component at the input terminal it just shows the result and then repeats the measurement for 5 times.Without a component it does 5 retries displaying "no component" and then switches off.

author: madires
author_rank: Super Contributor
timestamp: June 08, 2021, 07:23:06 pm
content: Either press the start button for > 300 ms when powering on or enable UI_AUTOHOLD in config.h. There are many configuration switches to optimize the firmware for your needs.

author: indman
author_rank: Super Contributor
timestamp: June 09, 2021, 05:44:32 am
content: Quote from: madires on June 08, 2021, 07:01:44 pmYes, this is the amount of current I measured on my TC-1 with a 3.7 V power supply at the time of launch. Later the current value can be kept at the level of 150mA.This is quite high,so the circuit requires a fairly capacious battery. From the +5V power supply, the circuit together with the display backlight consumes up to 30-50mA.

author: peteb2
author_rank: Regular Contributor
timestamp: August 25, 2021, 09:08:44 pm
content: So to take the thread into another (massive apologies) direction.... i have owned a TC1 for the last 4+ yrs & today just when i need it the battery is discharged... So as usual i've set it onto charge but this time.... NoGo! So here's my quandary:Replace the internal rechargable LiOn looking thing...& if i do that i might as well replace the ZiF socket that is hammered on '1,2,3' on a thing with a now yellowed coloured case with soldering iron burns *OR*... do i stump up for a new (probably badly made knockup rendition) *OR* is there a better alternative?I'm thinking a USB interface breakout module that interfaces with workbench PC that runs what the TC1 did and does in a GUI on screen, the same kind of thing but more accuracy ...please i'm a tech who fixes a lot of gear & yes i should at least fix my own old TC1, but is there a better alternative by any chance & not waste time o this used to death thing? I already own a Peak DCApro semiconductor USB curve tracer tester but it appears to have a lower range of ability than my old TC1... tia

author: madires
author_rank: Super Contributor
timestamp: August 26, 2021, 09:36:22 am
content: You could buy a new TC-1 and add a switch for the LiPo. If you're looking for alternatives check out the AY-AT clones, e.g. GM328A, and the Hiland M644. And if you program one of the two OSHW firmwares you'll get even more features. BTW, there are two mods for the TC-1 to make it compatible with the OSHW firmwares. The hardware mod also reduces the quiescent current to a few µA.

author: Feliciano
author_rank: Frequent Contributor
timestamp: August 27, 2021, 01:10:47 pm
content: If you easily find the spare parts you can try to fix the one you have, following the tips on the previous 5 pages (in most cases to replace the protection diodes ZD1 and/or ZD2 if you forgot to discharge a capacitor, as well as some caps that tend to leak or go short because the close to 40V on the Vz section of this device). If you end replacing the MCU, remember to reprogram or replace U4 with the alternative circuit (two transistors plus some resistors and diodes) before attempting to flash m-firmware or k-firmware.Or because these ttesters are inexpensive, you can buy the one that better suits your particular needs. Here, the main models at a glance:https://github.com/madires/Transistortester-Warehouse/blob/master/Documentation/English/Clone-Comparison-Chart.pdf

author: Felipe Lacerda
author_rank: Contributor
timestamp: October 17, 2021, 02:02:37 am
content: Quote from: Feliciano on August 27, 2021, 01:10:47 pmTC1 needs the mod to accept opensource firmware... doesT7-Hneed it too? what is the best choice?According to the table are the models that support upgrade to the 644.*I want to buy a new one, but I haven't found any on Aliexpress already with the 644.

author: F1RVC
author_rank: Newbie
timestamp: November 20, 2021, 10:36:32 pm
content: Hi, does somebody already had on a TC1 (M-tester V2.12k) a Zener value displayed always (with no component connected) at the startup?. All other functions look to be ok, if I put other kind of component , it is ok, but with no component it detect a zener and with a zener the measure is bad.I checked 37v (approx) is here, the zener voltage is going to PA4 thru a divider by 10, Should have 3,7v here but input look to be pulled down by PA4 and the low voltage is displayed like a zener voltage. Also the Ref voltage 2.5V (TL431) is also pulled down to 0V on PA3 by the 324PA, if I isolate PA3 the ref voltage rise up to 2,5V. If I isolate the PA4 , it also diplay a zener voltage at startup with 0V value !I do not tremember having done a bad measure with non discharged component , TC1 did it by itself one day at the bootup.Before trying to change the ATMEGA with a new one and flash it with the original TC1 firmware provided on this thread, maybe I missed something more easy to fix this TC1?Any advice or clue will be apreciated.If I start in this way , I will probaly tweak it with alternative k firmware and hardware U4 mod later (but before I would like to fix it ) ...

author: madires
author_rank: Super Contributor
timestamp: November 21, 2021, 12:59:15 pm
content: PA3 and PA4 should be in HiZ mode. If both suddenly short the input to ground then they most likely let the magic smoke out.

author: F1RVC
author_rank: Newbie
timestamp: November 21, 2021, 05:13:00 pm
content: That is my first thought too, but what is the link between both of them? If a problem would have been occured on PA4 (static or capacitor discharge, etc...) why PA3 is down too ?

author: madires
author_rank: Super Contributor
timestamp: November 21, 2021, 05:36:15 pm
content: I can only speculate. An over-voltage could also damage neighboring IO cells on the MCU die.

author: distefanom
author_rank: Contributor
timestamp: December 17, 2021, 09:04:07 am
content: I would ask anyone who has the circuit made using a couple of transistors, to replace U4 so allowing me to use the free firmware kindly available here.Since I don't have kikad on my PC, I would like if anybody could make me a screenshot of the complete circuit (I don't need the PCB layout) so I could replicate it on a bareboard.Thanks to anybody who can help.Mario

author: madires
author_rank: Super Contributor
timestamp: December 17, 2021, 11:41:28 am
content: Please seehttps://github.com/madires/Transistortester-Warehouse/blob/master/Hardware/TC1-Mod.pdf!

author: chris2u
author_rank: Newbie
timestamp: January 29, 2022, 03:44:20 pm
content: I just bought a TC1 recently....Generally all seems good....Although the micro USB connector was too far recessed for the cable to reach properly!....And don't expect the PCB to sit right down on it's supports..Probably due to the display being mounted too far off the circuit board, or maybe the supports are in the wrong place..The zener test voltage is 23.1V (Not over 30v as other units are) and am wondering if this is normal for this model ??This unit does not have the largish high voltage transformer but has 2 small inductors in the power supply section.Attached is a photo of the PCB.

author: madires
author_rank: Super Contributor
timestamp: January 29, 2022, 04:14:00 pm
content: Your TC1 seems to be another variation with two separate boost converters. To verify the output voltage for the Zener test you could reverse engineer the boost converter (IC and feedback voltage divider).

author: chris2u
author_rank: Newbie
timestamp: January 30, 2022, 07:09:15 am
content: Looking at the first set of specs from AliExpress, it mentions 20V for zener....Then later specs show 30V..So yes, like a covid 19 variant ...Needs another booster!.https://www.aliexpress.com/item/4001208715581.html?spm=a2g0o.detail.1000023.1.67d0549fikoqen

author: indman
author_rank: Super Contributor
timestamp: January 30, 2022, 08:57:32 am
content: Quote from: chris2u on January 29, 2022, 03:44:20 pmYes, this is normal, because as a DC-DC converter chip is used SDB628, which can adjust the output voltage range to a maximum of 28V! Exactly the same chip is used to produce a 7-9V input voltage for a 7805 stabilizer.

author: Felipe Lacerda
author_rank: Contributor
timestamp: February 01, 2022, 04:49:15 pm
content: Quote from: chris2u on January 30, 2022, 07:09:15 amTC-T7-His the best version available? Is this seller reliable?

author: chris2u
author_rank: Newbie
timestamp: February 02, 2022, 05:41:32 am
content: What I think would be nice is if you could change the colors allocated to the three inputs.This way I could have (1) Red, (2) Black, (3) Green, which was the color of the supplied leads and test hooks.It's would be a lot easier to identify what lead is what and what is base, collector and emitter and so on if things are the same colors throughout.ATM I'm having to order purple test clips from China as there are not too many around locally.Maybe some firmware genius could come up with a solution..

author: madires
author_rank: Super Contributor
timestamp: February 02, 2022, 02:38:25 pm
content: The m-firmware supports color coded probes/test pins and you can set whatever colors you like.

author: joseff701
author_rank: Newbie
timestamp: February 14, 2022, 04:03:59 pm
content: Hi, I tried a capacitor and after the tester did not turn on anymore, I removed the zener diodes DZ1 and DZ2, now it turns on but does not work, on 1 and 2 it says there are 1.46v. if anyone can help me understand what broke.

author: madires
author_rank: Super Contributor
timestamp: February 14, 2022, 05:56:36 pm
content: Toasted MCU IO pins, grilled by a charged cap. Can be fixed by replacing the MCU (and programming a firmware).

author: bob91343
author_rank: Super Contributor
timestamp: February 17, 2022, 05:59:53 am
content: My TC-1 consistently is fooled by a capacitor I have. This capacitor tests fine on my two bridges but when it comes to the TC-1 it doesn't know what to make of it. It will say unknown or give a completely incorrect value. Other capacitors from the same batch test fine.

author: distefanom
author_rank: Contributor
timestamp: March 04, 2022, 11:53:44 am
content: Hi Madires!After a looooong time, the micro finally arrived from china, on my workbench.I can now program the uP with the kind free firmware available around here.BUT, before doing it, I need now ask:With the free firmware, do I need to replace the U4 with the two-transistor circuit?When I program the IC, which fuse map do I need to use, so I could (theoretically) reprogram it ?I mean that I could -after programming the uP- reprogram it as many times needed to test different FW releases?I'm afraid that, with the wrong fuse map, after the first programing it will lock out itself, and I need to buy another uP.Please let me knowThanksMario

author: madires
author_rank: Super Contributor
timestamp: March 04, 2022, 01:15:14 pm
content: To make the TC1/T7 compatible with the reference design you can replace U4 with the two-transistor circuit or reprogram U4 (https://github.com/atar-axis/tc1-u4). For the fuse bits simply run "make fuses" after editing the Makefile (both OSHW firmwares).

author: distefanom
author_rank: Contributor
timestamp: March 09, 2022, 07:04:46 pm
content: Hi, MadiresIf I don't want to do the MAKEFILE, since I Have eXtreme Burner only in my PC,(see the attached image)Do you know what values I should put in the Fusemap, so the uP can be reprogrammed anytime?Please let me knowciaoMario

author: madires
author_rank: Super Contributor
timestamp: March 09, 2022, 07:37:45 pm
content: For ATmega324 and 16 MHz quartz crystal:- hfuse 0xd9- efuse 0xfc- lfuse 0xf7

author: distefanom
author_rank: Contributor
timestamp: March 09, 2022, 09:27:23 pm
content: Thanks, Madires !!!I'm missing "Lock fuse" and "calibration"Leaving them as FF and blank is enough?

author: madires
author_rank: Super Contributor
timestamp: March 09, 2022, 09:56:38 pm
content: Yep, simply ignore those two.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: March 18, 2022, 01:21:20 pm
content: Is the zener diode test somehow disabled in the alternative firmware?I tried testing a zener today (a 18V one) but no luck..

author: Gyro
author_rank: Super Contributor
timestamp: March 18, 2022, 01:25:19 pm
content: The tester is only capable of putting out a maximum of 5V (and a little less in practice).

author: belzrebuth
author_rank: Frequent Contributor
timestamp: March 18, 2022, 01:26:50 pm
content: Ahh okay.Thought TC-1 could measure up to 20V zener or something..edit:@Gyro I think you may be mistaken.TC-1 is able to test zeners so maybe my unit has a hardware problem since I've repaired it as can be read a couple of pages back in this thread.I'm using firmware 1.34m.

author: madires
author_rank: Super Contributor
timestamp: March 18, 2022, 02:07:55 pm
content: Quote from: belzrebuth on March 18, 2022, 01:21:20 pmQuote from: belzrebuth on March 18, 2022, 01:26:50 pmHave you enabled the Zener test in config.h? The settings should be:Code:#define HW_ZENER#define ZENER_DIVIDER_CUSTOM#define ZENER_R1 100000#define ZENER_R2 12000#define ZENER_UNSWITCHEDAnd in config_644.h:Code:#define TP_ZENER PA4You can find the required settings in the 'Clones' files.

author: madires
author_rank: Super Contributor
timestamp: March 18, 2022, 02:15:16 pm
content: Quote from: belzrebuth on March 18, 2022, 01:26:50 pmThe older models go up to about 40V. Later models have a different boost converter good for 30V or so.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: March 18, 2022, 03:16:25 pm
content: If I haven't done anything to firmware I should assume the diode test is disabled by default?Because I don't think I've configured anything; just transferred a hex file to the MCU IIRC..

author: indman
author_rank: Super Contributor
timestamp: March 18, 2022, 05:01:59 pm
content: Quote from: belzrebuth on March 18, 2022, 01:26:50 pmIf you are using this firmware version(1.34m), then checking the zener diodes can only be done from the main menu in the item "Zener". Automatic zener testing, which is similar to the Chinese factory firmware, is available in newer versions of m-firmware.

author: Gyro
author_rank: Super Contributor
timestamp: March 18, 2022, 05:13:05 pm
content: Quote from: belzrebuth on March 18, 2022, 01:26:50 pmIndeed I am. I'm clearly well out of date on these things, my apologies.

author: distefanom
author_rank: Contributor
timestamp: March 19, 2022, 09:12:23 am
content: Hi Madires, this morning replaced the U4 with the 2 transistor schematic and I tried to flash the micro (see the enclosed images).The programming has gone successful,But all I get is that splash screen, which holds until I have the button pressed, and nothing more happens.Maybe the firmware I used is wrong, but I don't have a link for the correct files,Can you help?Thanks

author: madires
author_rank: Super Contributor
timestamp: March 19, 2022, 11:06:56 am
content: For the m-firmware:- download source athttps://github.com/madires/Transistortester-Warehouse/tree/master/Firmware/m-firmware- see 'Clones' files for settings- edit config.h, config_644.h and Makefile- run 'make'- run 'make upload'

author: distefanom
author_rank: Contributor
timestamp: March 19, 2022, 12:19:29 pm
content: Sorry Madires, for my deep ignorance, so I still need help.Keep in mind that my Transistortester is a TC1, which has an ATmega324 @ 16 MHz quartz crystal (see the enclosed shot of it, my previous posts you can see the PCB) and I have an old Win7 PC:- I don't even know how to download ANY of those files from Github: even though, I'm a registered user, I can't find any "download" on any of those pages.-I don't have any ideaon how to compile the sources (if I could eventually download any of them) to have the right.eepand.hexfiles I need, to send to the micro via eXtreme burner.I'm not a developer, so I don't know how to "makefile" these...Could you or someone else help me with this harassment, since I would like simply to have those.eepand.hexfiles even the first edition is enough for me?Many thanks

author: belzrebuth
author_rank: Frequent Contributor
timestamp: March 19, 2022, 12:52:51 pm
content: To download you have to get to the master folder:https://github.com/madires/Transistortester-Warehouseand press code (green button).I imagine that you need to have WinAVR or mingw64 or maybe both to be able to "make"..Anyways I did run the command with default settings and I attached the output files (.eep and .hex).Hope it helps you.edit:Default settings shouldn't work for because I just saw that default frequency is 8MHz..Hmm..I should recompile with 16MHz and reupload..I could also wait for you to edit the Makefile to your needs and compile with that one maybe?Let me know how I can be of help.

author: madires
author_rank: Super Contributor
timestamp: March 19, 2022, 01:12:56 pm
content: Go tohttps://github.com/madires/Transistortester-Warehouse/blob/master/Firmware/m-firmware/ComponentTester-1.45m.tgzand click "Download" at the right side while not being logged in. And for getting started please seehttps://github.com/madires/Transistortester-Warehouse/blob/master/Documentation/English/FAQ.Feliciano.pdf. There's a ready-to-use k-firmware for the T7 (https://github.com/kubi48/TransistorTester-source/tree/master/trunk/mega644_T7_Mod) which could possibly also work with the TC1.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: March 19, 2022, 01:23:41 pm
content: Quote from: madires on March 19, 2022, 01:12:56 pmJust tried to upload it to my TC1 and I bricked it so I don't think that firmware works with the TC1...Is there any other .hex that can restore it now that I did what I did?

author: indman
author_rank: Super Contributor
timestamp: March 19, 2022, 02:09:45 pm
content: Quote from: madires on March 19, 2022, 01:12:56 pmMadires, k-firmware works only for ATMega644, it is not suitable for ATMega324.Quote from: belzrebuth on March 19, 2022, 01:23:41 pmHere is a ready-made working firmware for the clone TC1 and ATMega324

author: madires
author_rank: Super Contributor
timestamp: March 19, 2022, 03:36:35 pm
content: Quote from: indman on March 19, 2022, 02:09:45 pmMy bad. Some TC1s come with an ATmega324, some with an 644. MCU lottery.This is one of the reasons I don't provide any ready-to-use firmwares. There are simply too many hardware variations to cover.

author: distefanom
author_rank: Contributor
timestamp: March 19, 2022, 04:00:05 pm
content: Hi Indman!thanks for your efforts, but the link you provided me won't me download it, since it says the file is too big and I need Yandex installed.Which I did, but the installation program says that this program can't run in my region (Italy).BTW the processor inside my TC1 is an Atmega324, as I said several times.Personally, I don't think the .eep and .hex files should be so big, so maybe a direct link anywhere would be good enough.

author: distefanom
author_rank: Contributor
timestamp: March 19, 2022, 04:24:32 pm
content: Hi Indman. Sorry I didn't recognize itI successful programmed it in the Atmega 324. But I get kinda bootloop (see attached images) showing the first, then the second an then again the firstAlso seems to me that the image is shifted 2 dots left and 2 dots up in respect of the display itself.What's the meaning of the number shown?

author: indman
author_rank: Super Contributor
timestamp: March 19, 2022, 04:29:23 pm
content: Quote from: distefanom on March 19, 2022, 04:24:32 pmThis means that your device has a problem. Read advice from other owners on how to fix it.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: March 19, 2022, 07:11:40 pm
content: Quote from: indman on March 19, 2022, 02:09:45 pmMine has a 644 and I think I already have v1.34 somewhere, I was hoping for a newer edition of the m-firmware.I guess I need to roll my own..

author: distefanom
author_rank: Contributor
timestamp: March 19, 2022, 07:35:11 pm
content: Hi indman, I think no.Some weeks ago I broke my TC1 incidentally measuring a charged capacitor, I was sure it was already discharged.I'm a hardware engineer, and I found several damaged components on the testing path, like the protection diodes including DZ1, DZ2 as well the other resistors that go to the uP I/O ports (see the enclosed schematic for reference).Now they're all ok now, and changed the uP Atmega324 so I cannot imagine what else could be if not a FW problem.Maybe I should learn how "compile" the firmware, as you said, to tailor the sources to my TC1 device needs, but at my age, I find a thing really hard to do, starting from zero, as I am.I thought, as I already did with several other appliances, I felt it was way easier to find the already compiled FW and program it inside the micro.But I have to say is really harder than I thought.I'm still in the hope that someone else already has done it, and could kindly link me the firmware he/she used.Many many thanks to those who can help

author: indman
author_rank: Super Contributor
timestamp: March 20, 2022, 07:14:51 am
content: Quote from: belzrebuth on March 19, 2022, 07:11:40 pmHere is the working firmware for ATMega644https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg3578117/#msg3578117Quote from: distefanom on March 19, 2022, 07:35:11 pmBut I still think you're wrong! The firmware that I suggested is 100% working and tested on a very large number of clones like yours. Here is another 100% working firmware in Russian(1.41m) for your clone. Try it and if the display shows the same messages as on 1.34m, then your device has a hardware problem.Remove the protective diode assembly DZ2 for a while and check the operation of the firmware without it. I also advise you to check the quality of the soldering of the ATmega324 processor. Very often problems arise precisely for this reason. Check the resistances of each of the processor test ports(PA0-PA2) against +5V and GND. I also do not advise you to check the operation of the device with the USB charging cable connected.

author: distefanom
author_rank: Contributor
timestamp: March 20, 2022, 11:47:00 am
content: Hi indman!quote: "But I still think you're wrong!"Trust me indman, I really HOPE I'm wrong since I would like to recover this device, and not throw it into the bin!All the suggestions you give, like the DZ2 zener, all the protection diodes are already out of the PCB, as well to control the soldering joints of the I/O portsAlso there's no problem reading/verifying the uP at all.This evening I'll try you Russian version, and let you know.Thanks 4 the moment

author: stefanus
author_rank: Newbie
timestamp: April 19, 2022, 06:37:19 pm
content: You forgot to check DZ2, (SRV05-4) ,when you tested capacitor without discharged, DZ2 will protect forward/reverse voltage, and mostly DZ2 will short. ATMega will saved all the time.

author: distefanom
author_rank: Contributor
timestamp: April 19, 2022, 07:20:20 pm
content: I removed it already long ago.It still won't work and the micro shows what's in the attached photo-Of course it won't make any measurement

author: indman
author_rank: Super Contributor
timestamp: April 20, 2022, 12:59:59 pm
content: Quote from: distefanom on April 19, 2022, 07:20:20 pmOnce again I repeat to you, if you did not understand me before - your clone has a hardware problem and no other firmware will fix it! Use a multimeter to check the resistance of all measuring ports of the processor relative to + 5V and GND.

author: LesioQ
author_rank: Regular Contributor
timestamp: June 18, 2022, 04:59:57 pm
content: My tester TC-1 M-Tester died after a dozen of tests done (original factory graphical firmware).The first problem I noticed was erratical behaviour - sometimes it booted OK but failed to test, sometimes it was hung-up on logo screen.Sometimes the main screen display had pixel errors (image distorted).Upon some testing I noticed it bahaves better if 5V supply is lowered somewhat. I ended up adding a Si diode right after (U3) 5V stabilizer with caps. Now Vcc is 4.2V.It may be that communication with a LCD working on 3.3 Volt supply was causing problems.Now it's testing OK, but fails to complete a Self-test - hangs at 7-16%.Maybe someone can elaborate on that.

author: madires
author_rank: Super Contributor
timestamp: June 18, 2022, 05:58:24 pm
content: The tester needs 5V to run properly. Possibly a power supply issue, e.g. a broken MLCC. Do you have a scope to check the output of the boost converter?

author: LesioQ
author_rank: Regular Contributor
timestamp: June 18, 2022, 06:49:25 pm
content: Sure I do. I was searching for some fluctuations on Vcc 5V, but it looks OK. HV is 39V, (after C13 & C14 replacement).Vraw (5V stab. input) is about 9V.

author: madires
author_rank: Super Contributor
timestamp: June 19, 2022, 03:57:12 pm
content: A dodgy display (ST7735)?

author: mtcaus
author_rank: Newbie
timestamp: July 09, 2022, 03:20:12 pm
content: Solved the no power up issue. When the button is pressed, there is no display and Step-up/Boost IC at U5 is so hot. It could burn your finger. The fault is the Schottky barrier diode at D2. The diode with marking code SS18 (1A, 80V) was tested fine both in-circuit and out-of-circuit. Replaced it with SR2100 (2A, 100V) and the unit is working again. Measured the peak voltage of 52V at the cathode side of SR2100 Schottky diode when the button is pressed. Since the voltage rating of 1206 SMD capacitor at C11 is only 50V. Eventually C11 will give up. I replaced it with an electrolytic capacitor Rubycon 4.7uF @50v. I couldn't find a higher rated voltage of capacitor. Ideally should be like 100v. However, when I tested the Rubycon withstand voltage, it could go up to 100v. No wonder Rubycon capacitors are good. Anyway, fixed the unit by replaced two components at D2 and C11. See photo fixed.jpg.From the transformer, when the button is pressed, there are two outputs, 9v (for powering the unit) and 37v(at least for Zener diode testing). See photo Bottom.jpg. Mine was like 2v on either path. Obviously there was a short somewhere. Through the process of elimination, I removed Schottky diode first. I got the 9V back. At first I thought ATMEGA324PA was the fault, but it was tested fine when applying 5V directly. See photo Top1.jpg and Top2.jpg. At first replaced D2 with SS24(2A, 40V) for testing. Obviously the voltage is not rated high enough. The diode was so hot and high pitch sound can be heard from the transformer when power up. Since I don't have any other SMD Schottky diode with a voltage rated that high. I used a through-hole Schottky diode SR2100 and there is enough space to install it. For the capacitor at C11, it will give up eventually if the peak voltage repeatedly go above the rated 50v 1206 SMD capacitor. This maybe the reason why people reported C11 shorted in the forum.My LCR-TC1 is from the original creator. The original has 3 Chinese characters (浩祺心) on the top of the circuit board. See photo Top1.jpg. The component layout may be slightly different than yours since there are so many clones out there. However, the general layout is the same.I have been troubleshooting this unit for a while. Replaced numerous Step-up/Boost IC ALxxx at U5 with different numbers. xxx are three numbers. The numbers do not matter if anyone who cares to know. Even bought STC15L104W chip at U4 and programmed it. By the way, I couldn't find the original U4 firmware. Luckily I didn't overwrite the original chip. Obviously none of them worked until I replaced Schottky diode at D2. The time and money spent may not justify, but the feeling of successfully fixed the unit is worth it. Hope this post will help someone out there.

author: masster
author_rank: Regular Contributor
timestamp: August 09, 2022, 11:27:46 pm
content: I bought today my TC1. As many other users before me, I calibrated the tester then started to check parts.After maybe 8 parts measured, the tester turned off as usual by himself, but never came back on. It is dead. I didn't check any capacitor, only resistors, transistors, and a diode.I thought the battery is low, although the tester showed 3.85V. I charged it on USB and after 10 minutes the LED turned from red to green. Yet still no luck. The tester is dead.Full of confidence, I opened the case, hoping to change two capacitors and move on. But... surprise! Although on the outside, my TC1 looks identical to the rest of TC1's in this topic, on the inside there is another story. A totally different parts layout. See attached photo. I managed to read the codes on each IC and annotated the photo accordingly.So my question is: how should I diagnose for the fault? Anyone happens to have the schematic for this version?Many thanks in advance if you can help me.

author: masster
author_rank: Regular Contributor
timestamp: August 10, 2022, 05:46:43 am
content: Update:The output of 78L05 (VCC) is shorted (3.5 ohms). What is the best method to decide which component is shorted? Capacitors, input protections, IR receiver, MCU, ATMEGA itself.

author: TurboTom
author_rank: Super Contributor
timestamp: August 10, 2022, 07:24:39 am
content: If you have a thermal imager, attach a current limited lab supply to the shorted supply line (set to maybe 100mA) and observe what component heats up. This is also possible without such gear: if you use a sprayer (the type used for misting flowers) filled with isopropanol or ethanol and spray the board with a very thin layer of the liquid, you can usually observe where it evaporates first. Good luck!

author: masster
author_rank: Regular Contributor
timestamp: August 10, 2022, 07:37:45 am
content: 78L05 has a maximum output current of 100mA with proper heat dissipation.How much current draws the device on 5V when measuring?

author: madires
author_rank: Super Contributor
timestamp: August 10, 2022, 11:33:08 am
content: I don't know the specific current draw for that model, but usually it's about 15mA on average for the 5V rail.

author: mtcaus
author_rank: Newbie
timestamp: August 10, 2022, 09:32:42 pm
content: TC1 will very likely break down after continuous tests in a short period of time because it always generate high voltage for zener diode test every time. The components along that path simply cannot take it. Your unit is the newer design, but it's basically the same. Instead of one transformer with two outputs, your design simply uses two sets of inductors and step-up converters. By looking at the photo, you have a burnt resistor R24 circled in green. You should also check all the components circled in red. I saw your circuit online somewhere before. Just search around and you can find out the value for your R24.

author: masster
author_rank: Regular Contributor
timestamp: August 10, 2022, 11:45:39 pm
content: @mtcaus

author: indman
author_rank: Super Contributor
timestamp: August 11, 2022, 07:06:52 am
content: masster,a malfunction in these clones with certain skills in repair and understanding of the principle of their work is found in a couple of minutes.The schematic diagram of your clone will roughly correspond to the scheme on the LCR-T7H, only the numbering of the elements will be different. R24 will correspond to R13 on my circuit and will be 10Kohm.If you have a heated 7805, then there is a high current consumption.We need to determine the cause.Remove the 7805 from the circuit and check its serviceability separately using an external power supply. Also, temporarily remove the U2 diode assembly(SRV05) and the 6V8A suppressor from the circuit. Then check with the multimeter whether there is a low resistance at the output of the 7805 (3.5 ohms)?

author: Per Hansson
author_rank: Unknown
timestamp: August 11, 2022, 08:56:15 am
content: Quote from: mtcaus on August 10, 2022, 09:32:42 pmIsn't it just installed with the bottom side facing up?

author: masster
author_rank: Regular Contributor
timestamp: August 11, 2022, 09:31:43 pm
content: @indmanThank you for your reply. I know you researched this tester heavily. The only thing that keeps me from doing a better job in diagnosing the issue is the microscopical size of the parts. I wanted to minimize the intervention on the board because I really hate it working with heavy magnifying glasses for electronics or with a microscope.Anyway, I have desoldered in turn the following parts: 78T05, the two filter capacitors on the 5V output, the input protections (6V8A and SRV05-4), and the IR receiver.Shorted parts found: SRV05-4 and the IR receiver. Yes, I know. The latter being faulty was a total surprise.I find that the quality of the parts used in these tester clones is deplorable (POS), hence the low price. In fact, the seller didn't offer any guarantee. Although after replacing the bad parts the tester will most probably work, it is very unreliable. Who knows what else will break? My advice? Don't waste the money on those China clones. Make one yourself with good quality parts, maybe in bigger size to avoid doing neurosurgery on the board, and definitely I would try finding a better input protection because right now if somebody is messing with the input pins by shorting them inadvertently or forgetting a cap is not discharged, he will look again(!) at a dead tester.@Per HanssonYou are right. The resistor was soldered upside down. I measured it after desoldering. It has 10k indeed.

author: indman
author_rank: Super Contributor
timestamp: August 12, 2022, 07:20:47 am
content: Quote from: masster on August 11, 2022, 09:31:43 pmYour problem does not in any way confirm the low quality of Chinese parts, although such a reality certainly exists.A short circuit immediately in 2 parts allows us to conclude that there was some surge of increased voltage, which these parts took over. Put it back in place 7805 (if intact) and turn on the tester without SRV05-4 and the IR receiver. The device should turn on and work without them.Very often the culprit of similar malfunctions is static electricity.Quote from: masster on August 11, 2022, 09:31:43 pmOf course, you are right that a thing made with your own hands will bring much more benefit and experience than a purchased one!But on the other hand, thousands of Chinese clones work well for many people and they don't bother looking for other options.

author: masster
author_rank: Regular Contributor
timestamp: August 12, 2022, 10:35:51 am
content: @indmanI have soldered back in place just the 78L05 and 6V8A. The display came back to life, but instead of showing "No, bad part, or unknown part" message, it shows Cell 1.84V between pin 1 and 3.I remind you that I didn't test any capacitor whatsoever from new. Moreover, when I worked on the board, I used an ESD wristband.

author: madires
author_rank: Super Contributor
timestamp: August 12, 2022, 12:13:11 pm
content: Most likely the ATmega was damaged too.

author: indman
author_rank: Super Contributor
timestamp: August 12, 2022, 12:59:34 pm
content: Quote from: masster on August 12, 2022, 10:35:51 amIt takes a very good reason to make several parts malfunction at once.Wouldn't you agree?If you rule out static electricity and an undischarged capacitor, it will not be easy to find the cause of such an occurrence with your clone.I do not exclude the possibility that somehow in an incredible way the voltage that is created to test the Zener diodes (25V) hit the input of the measurement ports of the processor and knocked out the protective assembly, IR and the ports themselves.In my practice there have been several cases where the part for testing was placed on the K contact on one side and on one of the 1-2-3 test contacts on the other side.

author: masster
author_rank: Regular Contributor
timestamp: August 12, 2022, 03:42:03 pm
content: 1) What is the maximum voltage/current supported by the input ports of ATMega?2) Is there a better solution to protect the input ports against charged capacitors?3) Is there a better solution to protect the input ports against wrongfully connecting tested parts? Fool proof and full proof.

author: indman
author_rank: Super Contributor
timestamp: August 12, 2022, 04:05:22 pm
content: Quote from: masster on August 12, 2022, 03:42:03 pmThis information can be found in the datasheet of the AVR. MaxVoltage -5.5V, MaxCurrent for 1 port - 40mA,for all ports -200mAQuote from: masster on August 12, 2022, 03:42:03 pmYou can replicate the protection circuit using a relay with 3 contact groups as shown in the Karl-Heinz manual.But as correctly noted by the authors of the project - no protection provides a 100% protection guarantee. The same goes for the answer to your question №3

author: masster
author_rank: Regular Contributor
timestamp: August 13, 2022, 01:58:55 am
content: QuoteIf the display says "Testing..." and after 5 seconds it shows "Cell, 1.40 V between pin 1 and 2" , is that definitive proof the ATMega is damaged?

author: indman
author_rank: Super Contributor
timestamp: August 13, 2022, 05:22:55 am
content: Yes, this is one of the characteristic signs that one or more measuring ports of the processor are damaged. To make sure of this definitively, you can check the resistance of each port relative to GND and VCC. Provided that the SRV05-6V8A protective assembly is removed and nothing else is connected to the ports in parallel.You can also believe whether the nominal values of the measuring resistors 680ohm and 470k are in order. If they are in good condition, and the port resistance is very different, then this indicates damage to the processor.

author: masster
author_rank: Regular Contributor
timestamp: August 14, 2022, 01:45:53 am
content: I decided to remove the 6V8A and SRV05-4 to measure the resistance between each pin of ATMega and GND. See schematic below. Where there is no resistance value, the resistance is higher than 2 Mohm.I find abnormal the resistance between VCC and GND, which is still low IMO. I have used an external power supply for VCC and I have measured a current consumption of 170 mA. That is way too high, over what 78L05 can deliver. Hopefully there is another faulty filtering capacitor on the VCC bus. I didn't remove them all. I still have hope that ATMega is not toasted.Please have a look at my resistance measurements and tell me what else you find odd. I don't like the values on pins 34 to 37, corresponding to PA0 to PA3.Right now, with external VCC supply and battery connected, I get the Cell of around 1.2V between 1 and 2. Sometimes I get a Cell between pin 1 and 3.

author: mtcaus
author_rank: Newbie
timestamp: August 14, 2022, 10:54:14 am
content: There is one more area you could check for your issue before you determine its ATmega. Check your testing sockets for any possible "shorts". I once bought a ESR02 PRO and it's working "fine". However once in a while after testing a few components, I would get calibration screen or show pin 1(3) and pin 3(2), (random pins) shows a cell, resistor or capacitor just like yours, but there is none on the testing sockets. Upon close inspection, I saw a solder sticking out from 1 test socket to another. They weren't touched each other, but enough to cause weird problems. I removed it and the problem solved. It's a manufacturing defect.

author: masster
author_rank: Regular Contributor
timestamp: August 15, 2022, 02:47:22 am
content: I didn't find any short between input pins.Instead, I took another thermal image (see attached) and there is a hotspot on filter capacitor C7. Fingers crossed. By the way, what value have the filter capacitors? 10 uF and 0.1 uF ?The output voltage of first step up converter is 6.67V (correct according to resistor divider (0.6 x (1+100k/10k)) but lower than 2 Volts over stabilized voltage of 5V.The output voltage of the second step up converter is 22.6V, again correct.

author: TurboTom
author_rank: Super Contributor
timestamp: August 15, 2022, 01:07:05 pm
content: No, the hot spot is not C7. The optical overlay over the thermal image isn't accurate at these close distances, the hot component is the Atmel. Better disable optical overlay when working at close distaces and use common sense...

author: masster
author_rank: Regular Contributor
timestamp: August 15, 2022, 06:06:50 pm
content: What optical overlay are you talking about? There is no such thing. The image on the left was taken with a regular phone camera. The image on the right came directly out of the FLIR device, and it is not in overlay mode.I have cropped the left photo to look similar to the framing of the FLIR photo. Moreover, what common sense are you talking about? Condemning the ATMega chip by default? I'm looking for a short circuit on VCC bus. What is wrong with a capacitor being shorted? What do you know about the precision and resolution of the FLIR device I'm using? Nothing.

author: TurboTom
author_rank: Super Contributor
timestamp: August 15, 2022, 06:14:49 pm
content: Sorry I didn't mean to sound rude or to offend you. But if you look at the colour grading of the heat distribution, you can clearly see the "X" shape of the chip carrier inside the Atmel. And with "common sense", I mean, that at a maximum temperature of sixtysomething degrees, just use your finger for a quick check. I'm absolutely sure that in this case, it's the Atmel that's getting hot. And the thermal image surely looks as if there is a visual overlay. The thermal image itself is quite out of focus, so the sharp structures visible in there cannot be part of the thermogram. I hope this makes sense...P.S. FYI, I attached a true in-focus close-up thermogram of my (old style) TC1 PCB after maybe three consecutive testing cycles. You can clearly see the metal chip carrier inside the AtMega's enclosure. But you can also see the (reflective metal) terminals that don't emit heat. Obviously, temperature difference of this intact unit is much lower than you found on yours. If you look carefully, you see two of the tiny SMD resistors get slightly "warmish" -- the high side of the zener voltage divider and the shunt of the voltage reference -- and that the copper tracks below the silkscreen dissipate some of this heat. Thermal camera is a "pimped" Flir E4 with an additional close-range ZnSe lens with a focal length of 75mm IIRC. Without this optics, close-range thermographs aren't possible with this entry-level thermal imager.

author: Per Hansson
author_rank: Unknown
timestamp: August 15, 2022, 06:37:46 pm
content: Quote from: masster on August 15, 2022, 06:06:50 pmPlease look at the thermal picture of the crystal, and where it is in the photograph from the Flir:

author: masster
author_rank: Regular Contributor
timestamp: August 16, 2022, 11:24:30 pm
content: After I removed capacitor C7, the current consumption dropped to 57 mA when testing (from 170 mA). No more overheating on the board.The tester looks functional now. I have to replace the faulty 78L05 chip, the SRV05-4, and the filtering capacitors I removed.Thank you for your replies.

author: TurboTom
author_rank: Super Contributor
timestamp: August 17, 2022, 07:53:48 am
content: Yes. Of course. Good luck with your repair!

author: shved
author_rank: Regular Contributor
timestamp: August 17, 2022, 11:07:00 am
content: Been there, done that. I've also had excessive power draw. Double check the caps, esp. C6 & C7. Also check for corrosive flux. Give a quick read to the rest of the thread.

author: masster
author_rank: Regular Contributor
timestamp: August 17, 2022, 12:08:37 pm
content: Quote from: TurboTom onTodayat 12:53:48 am>QuoteDespite your useless sarcasm, the device works. Learn to accept you were wrong. Good bye.

author: TurboTom
author_rank: Super Contributor
timestamp: August 21, 2022, 09:28:56 am
content: @masster:I'm not questioning your repair success. But I would really like to understand the undisputable findings that in your thermal image, the microcontroller heated up while this cannot be clearly told for the capacitor. The thermal part of your image is too far out-of-focus to tell.I assume you took the images with a FLIR ONE or a similar device which has the thermal and the optical cameras installed side-by-side, so at close distance you've got a parallax error. The wide angle optics will result in this problem to vanish at higher distance. Moreover, there may be some active correction for this parallax error built into the thermal imager's software. FLIR's more recent cameras offer an optical overlay mode that they call "MSX" which is enabled by default. And that's contributing the apparent in-focus structures in your thermogram. Try disableing MSX display mode and experiment a little with your TIC.If the replacement of the apparently shorted capacitor C7 (and maybe the 5V linear voltage regulator) brought your TC1 back to life as you reported, and the microcontroller no longer heats up, the only explanation for this is that the designer of this PCB made a bad error: He may not have connected all the supply lines of the ATMEGA to Vcc individually and have the node where C7 is attached floating. This means, C7 will buffer this supply line but power will flow over the metallization of the ATMEL's die. And if C7 shorts this supply, this metallization layer can well become a heating element. It would be interesting to check that on the current TC1 version's PCB... As I reported before, my TC1 is of the previous design with the single voltage converter and the transformer.Depending on the ruggedness of the ATMEGA die and the current limit of the voltage regulator, this may or may not cause permanent damage to the microcontroller.That's IMO the only reasonable explanation that a shorted capacitor C7 may result in the microcontroller to heat up.

author: MarkMLl
author_rank: Frequent Contributor
timestamp: August 25, 2022, 01:34:08 pm
content: I'm just about to lob one of these into the spares bin, I've spent more time on it than it's worth. However, a couple of comments if I may:The PCB is as shown in Kamlakkannan's #78 with silkscreened "LCR-TC" and "XR-112" markings, and an unpopulated 8-pin outline next to the ISP header position.C11, 12, and 13 appear to be in roughly the same place and have the same function on all boards discussed (all appear good in my case).C6 and in particular C7 appear to vary. On my (and most) boards they're associated with U4 (8-pin chip probably STC) while on the board discussed by Masster C7 is associated with the Atmega's pin 38 (Vcc).I agree with the points made by various people about the parallax error between the optical and IR optics on IR cameras. I'm surprised that there isn't an offset table, either on the side of the camera or at least in the manual.MarkMLl

author: PcarSBA
author_rank: Newbie
timestamp: January 09, 2023, 06:47:27 pm
content: Hi,I blew up my Atmega324 based TC-T7-H transistor tester by connecting a 470uF capacitor charged to 5V to pin 1 and 3It took out the TVS diode array. With it removed the Atmega324 comes on again but I get the dreaded 4.1V cell voltage between 1 and 3. Pin 3 has 56Ohm to Vcc. And that resistance remains with it lifted off the PCB when measuring the pin directly to Vcc.So I conclude that I need to replace the Atmega. Can someone help me decide what version of main firmware I should or can install onto the new Atmega324. I read through a lot but am still not clear as to whether I also need to change firmware on the STC15W104 when I pick one of the versions of Github?Thanks for any help

author: abdulbadii
author_rank: Frequent Contributor
timestamp: February 02, 2023, 02:32:33 am
content: original C is non polarized C isn't it, how can be replaced by polarized one?

author: madires
author_rank: Super Contributor
timestamp: February 02, 2023, 11:55:04 am
content: Quote from: PcarSBA on January 09, 2023, 06:47:27 pmIf you want to run one of the two OSHW firmwares you need also to reprogram the STC15W104 or replace it with a simple 2-transistor circuit.

author: madires
author_rank: Super Contributor
timestamp: February 02, 2023, 11:55:42 am
content: Quote from: abdulbadii on February 02, 2023, 02:32:33 amWhich cap do you mean?

author: Siriano53
author_rank: Newbie
timestamp: March 16, 2023, 06:07:44 pm
content: Salve a tutti. Grazie per le vostre discusion sui possibili guasti del tester tc1.Il mio tc1 si è risvegliato sostituendo il 78L05 e zener l'SRV05.

author: gianb_diazm
author_rank: Newbie
timestamp: March 29, 2023, 02:43:19 am
content: Hi everybody,I'm also the proud owner of a malfuctioning T7 component tester, but it's not suffering from the two typical failures described here. My tester is stuck in the Zener testing mode and won't budge from there. I was testing some Zener diodes, and having forgotten that you're supposed to use the KAA section of the ZIF connector, I was using the 123 section. I realised my mistake and started moving the wires around when I saw it: the little spark of death. Long story short, I derped out and gave the 123 testing probes a good ZenerZap™, and now it thinks everything is a Zener.The tester is this one exactly:https://a.co/d/3DXImdQThe PCB looks exactly like this one:https://vrtp.ru/uploads/post-39-1674996347.jpg, it says C5.1.3_2022/5/25I have tried desoldering different components from the board to try and break its Zênerie (Zener rêverie lol), to no avail. It turns on, charges the battery, decodes IR and even speaks serial to the Arduino IDE at 500000 baud.Any ideas?

author: madires
author_rank: Super Contributor
timestamp: March 29, 2023, 10:28:44 am
content: Most likely the ATmega's probe pins are zapped, and the ATmega needs to be replaced.

author: indman
author_rank: Super Contributor
timestamp: March 29, 2023, 10:46:07 am
content: madires, if it has exactly the same circuit board as he indicated in the link, then this is a Chinese processor, for which there is no working firmware yet.gianb_diazm, remove the U7 chip from the board and turn on the tester again. What will be on the display?

author: gianb_diazm
author_rank: Newbie
timestamp: March 29, 2023, 08:20:29 pm
content: Hello again and thanks in advance,Even though the boards are identical, mine has a real ATmega 328P, instead of that U1 chip on the picture I linked to. I didn't catch the difference until afterindmanpointed it out.Also, I removed U7 and it's still showing Zener. I have removed before, out of desperation more than anything, L1, the R6 and R7 voltage divider, U6, D1, R16, D2, basically anything less than 2 traces away from the KAA probes. In all cases, it shows the Zener test and a random 3.4ish voltage.I forgot to mention, whenever I short all the 123 probes, the tester goes into selftest mode no problem, so there might be some hope left for the device.I wouldn't mind losing the Zener functionality as long as the rest of the tester works, as I mostly use it for MOSFETs and the like.

author: indman
author_rank: Super Contributor
timestamp: March 30, 2023, 05:35:05 am
content: Quote from: gianb_diazm on March 29, 2023, 08:20:29 pmUnfortunately, you are mistaken. If you have the same board as I showed in the photo below, then this is not a real ATMEL, but a Chinese fake. In fact, the APT32F172 processor is installed, it’s just a fake marking on the case. This has already been proven 100% and many buyers of similar clones have already successfully won the dispute and returned the wasted money. This Chinese controller is damaged on your board with 99.9% certainty, so return to life this clone is unrealistic.

author: gianb_diazm
author_rank: Newbie
timestamp: March 30, 2023, 07:04:43 pm
content: Yes, it's exactly that board, down to the markings on all the chips. A very convincing forgery!Well, such is life. I guess I'll have to replace the microcontroller then.It's a real shame that these MCUs are not reprogrammable, because I could've reused the chip for a digital pins-only project.Thanks a lot for the help and the patience!

author: elecdonia
author_rank: Frequent Contributor
timestamp: April 02, 2023, 10:41:31 pm
content: Quote from: indman on March 30, 2023, 05:35:05 amTwo dead give-aways for identifying LCR-Txx units with APT32F172 MCU:1) MCU has 32 pins2) There is no crystal anywhere on the PC boardOther details often found in LCR-Txx units with APT32F172MCU:- A pair of LMV358 dual op-amps at locations U9, U10 (I'm still in the process of learning exactly why these opamps are used)- D2 cathode connecteddirectlyto test socket "K" pin for zener diode test. This circuit is guaranteed to fail. Before using the zener test feature the trace between D2 and pin "K"mustbe cut and a series resistor installed.2.2k ohmsworked well for me.This is important!DO NOT test zenersbefore making this series resistor modification!

author: elecdonia
author_rank: Frequent Contributor
timestamp: April 02, 2023, 10:44:22 pm
content: Perhaps someone with PC board layout talent will design a small adaptor PC board for replacing the APT32F172 with either ATmega328P or ATmega324?Although the pinouts are considerably different this still might be feasible.

author: Glide
author_rank: Newbie
timestamp: May 11, 2023, 07:28:38 am
content: My one is showing just zener diode now, I found out that D2 is dead. Can you please tell me the value for D2.

author: madires
author_rank: Super Contributor
timestamp: May 11, 2023, 08:14:21 am
content: If D2 is related to the boost converter for the Zener test voltage then it should be an SS18. Any jellybean Schottky diode rated for >=80V is fine.

author: Glide
author_rank: Newbie
timestamp: May 11, 2023, 10:04:18 am
content: Thank you, I have around a BAS86 but is rated just for 50V. You think I can use it?

author: madires
author_rank: Super Contributor
timestamp: May 11, 2023, 11:37:29 am
content: It depends mainly on the output voltage of the boost converter and the type of converter. There are several models of the TC-1 (and family) with Zener test voltages ranging from about 25V up to 45V. For a model with a lower output voltage a 50V Schottky could be ok.

author: Glide
author_rank: Newbie
timestamp: May 11, 2023, 12:12:10 pm
content: I think is busted, now is showing 330pF 1-3 without nothing connected.

author: Nokeshas
author_rank: Contributor
timestamp: May 11, 2023, 12:43:00 pm
content: Hello colleagues,I have this TC1 board variant with atmega328pu and since accidentally put charged capacitor to 1-3 i fried atmegas inputs and everytime it show that any device is a small voltage battery.I have one atmega328pu chip laying around...maybe someone have original firmware from that atmega chip.And can somenone explain how to program that atmega328 with that firmware/program if i have only ftdi usb programer.Sorry for stupid questions, but in this kind of jobs i am noob.Thanks in advance.

author: madires
author_rank: Super Contributor
timestamp: May 11, 2023, 01:23:52 pm
content: Quote from: Glide on May 11, 2023, 12:12:10 pmDoes removing the SRV05-4 help? Otherwise the ATmega could be toasted.

author: madires
author_rank: Super Contributor
timestamp: May 11, 2023, 01:32:52 pm
content: Quote from: Nokeshas on May 11, 2023, 12:43:00 pmSame advise, remove SRV05-4 (U2) and check again. If this doesn't help replace the ATmega and go for one of the two OSHW firmwares. Your specific model doesn't need the STC15L104W mod.

author: Nokeshas
author_rank: Contributor
timestamp: May 11, 2023, 02:59:24 pm
content: Hi,thanks for answer.I have tried to remove U2, but the same result... detecting only low voltage battery.(that is not connected at all)Regarding your suggestion to swap those atmega328.Where to get those firmwares that you mentioned (tried to search in this thread, but with no luck).And another question.I have this thing FTDI: (picture attached) can i do reprogram atmega328 with that thing and some tutorial would also be awesomeI am not familiar with programming these...

author: madires
author_rank: Super Contributor
timestamp: May 11, 2023, 05:06:26 pm
content: Firmwares and documentation:-https://github.com/kubi48/TransistorTester-source-https://github.com/madires/Transistortester-WarehouseRegarding the FTDI please search for 'avrdude FTDI'. And there are also tons of websites explaining the AVR toolchain and how to flash an ATmega.

author: Glide
author_rank: Newbie
timestamp: May 12, 2023, 06:59:57 am
content: I remove U2 (10A45 on the chip) and now is stuck on "Testing...". It seams that I'm getting somewhere:)). Any other suggestions?

author: madires
author_rank: Super Contributor
timestamp: May 12, 2023, 10:09:32 am
content: What happens when you check a resistor?

author: Glide
author_rank: Newbie
timestamp: May 12, 2023, 09:14:31 pm
content: Nothing, is not getting unstuck from this state. Only if I disconnect the battery is shutting the screen off, otherwise is staying like with that message on forever.

author: madires
author_rank: Super Contributor
timestamp: May 13, 2023, 10:25:21 am
content: That points to a broken MCU. If your tester has a genuine ATmega you could replace it and flash one of the two OSHW firmwares. Possibly you need also to reflash the control MCU or replace it with a simple two-transistor circuit.

author: Nokeshas
author_rank: Contributor
timestamp: June 26, 2023, 03:15:59 pm
content: Hello, well i have tried lots of things...Last one - flashed with avrdude 3.3 original firmware, but i get just short light up of display and nothing else.verified lock and fuses all ok, eprom and firmware also verified ok, but still nothing on the screen just short splash of lcd backlight and thats it...my tc1 has atmega328p so in config everything selected fine i think.fusesEXTENDED = 0xFF (valid)HIGH = 0xD7 (valid)LOW = 0xFF (valid)lockLOCKBIT = 0xC0 (valid)

author: madires
author_rank: Super Contributor
timestamp: June 26, 2023, 03:39:06 pm
content: Erase the whole ATmega to reset the lock fuse. Then set h-fuse 0xd9, l-fuse 0xf7 and e-fuse 0xfc. After that program the firmware (flash & EEPROM).

author: Nokeshas
author_rank: Contributor
timestamp: June 26, 2023, 03:51:28 pm
content: done, still the same, lcd only lights up on pressing button and thats it.

author: madires
author_rank: Super Contributor
timestamp: June 26, 2023, 04:34:55 pm
content: The pin assignment for the power control could be incorrect. AFAIK, it should be PB1.

author: Nokeshas
author_rank: Contributor
timestamp: June 26, 2023, 06:01:02 pm
content: i got LCR-TC1(T7)ATMega328DIP firmware since my board is with ATMega328DIP.Flashed atmega, but display is show wrong and its not like original firmware that was before with graphics not only text.Is there a way to put atmega324 firmware to armega328p?Actually the best help would be to get files for avrdude to program it, i have tried to read about something like makefile, but cant understand there anything since i do not have resource for starting up linux os.... maybe someone can help me regarding this? My TC1 model is with dip ATMEGA328P.Thanks in advance

author: madires
author_rank: Super Contributor
timestamp: June 27, 2023, 08:32:33 am
content: The display offsets are a bit off. You can't simply progam an ATmega328 with a 324 firmware as they have different port pins (need to be adapted). The AVR tool chain is also available for Windows, and there's Microchip's IDE too.

author: Nokeshas
author_rank: Contributor
timestamp: June 27, 2023, 12:31:52 pm
content: WELL..1. installed WinAVR-20100110-install2. extracted contents from avr8-gnu-toolchain-3.7.0.1796-win32.any.x86_64.rar to winavr directory.edited makefile, config.h, config_328.h (to specify correct display)started programers notepad(winavr)opened makefiletools-> make all -> pile of errors.i think i wasted enough time = time to buy new tc1

author: madires
author_rank: Super Contributor
timestamp: June 27, 2023, 01:01:53 pm
content: If you prefer to buy a new one be aware that many come with a different MCU (APT32F172K8T6 or LGT8F328) at the moment. And the firmware is poorly adapted, i.e. a few measurement results are really bad and less features. Some even lack the self-adjustment.

author: Nokeshas
author_rank: Contributor
timestamp: July 03, 2023, 10:20:02 am
content: i have solved "tools-> make all -> pile of errors."problem with uploading msys-1.0.dll new version to winavr installation folder.Now i have fully working, with correct lcd offsets and other corrections TC1 dip atmega368p model with 1.47 M firmware since i have not been able to adopt it to 1.49 or 1.48.But also done mistake and ordered TC1.in the picture is what arrived... i have never seen that board, there is no quartz and also it is fake atmega328p i think it is APT32F172K8T6 or LGT8F328.I agree ... poor device cant identify some components and when self testing it - no firmware version shown.Maybe there is some known seller or source where i can get tc1 or tc2 with real atmega324pa?Thanks

author: madires
author_rank: Super Contributor
timestamp: July 03, 2023, 01:15:01 pm
content: Yep, your new TC1 has an APT32F172K8T6. Here are some hints on identifying the MCU:- MCU in DIP is usually an genuine ATmega.- APT32F172K8T6 has different power pins:- 32-LQFP/QFN: 18=Vss, 19=Vdd (ATmega328 32-TQFP: 5=Gnd, 4=Vcc)- APT32F172K8T6 uses SWD port for ISP:- 5 pins: Vdd, Vcc, F_SDAT, F_SCLK, F_RST- Testers with APT32F172K8T6 often lack a quartz crystal.- LGT8F328 has slightly different pins:- QFP32L: 21=PE2/SWD (ATmega328 32-TQFP: 21=Gnd)- LGT8F328 uses SWD port for ISP:- 5 pins: Gnd, Vcc, SWD, SWC, Reset- Clone variants with an genuine ATmega are usually about EUR/US$ 5 moreexpensive than the variant with a different MCU.

author: jimmc
author_rank: Frequent Contributor
timestamp: July 16, 2023, 04:12:10 pm
content: Yet another version here.Processor appears to be LGT8F328 and ISP 5 pins: Vcc, Gnd, Reset, SWD, SWC.Firmware reported as 3.12K.As supplied about 1 in 5 starts gave a jumbled screen (see pic), restarting after timeout gave normal screen.I guessed the the processor might be starting before the screen and not initialising it correctly.I tried adding a 100n capacitor between RSTN (pin 29) and ground (physically between R22 and the end pin of the display).So far this seems to have cured the problem.Jimps Thanks to madires for all the hard work he has done on these devices.

author: galaga1982
author_rank: Contributor
timestamp: July 21, 2023, 05:53:01 am
content: Hello madires,I also had an unfortunate incident where TC1 broke down while testing a charged capacitor. To be honest, I knew for the first time that measuring a charged capacitor could damage the device.Anyway, trying to replace zd1 (6V8A) zener diode and dz2 (SRV05-4) diode.dz2 (SRV05-4), SEMTECH is no problem to obtain, but ZD1 (6V8A) was difficult to know the exact PART NUMBER and MAKERAs you know, there's a lot of fake online. I would appreciate it if you could let me know the part information you know.Thank you.

author: madires
author_rank: Super Contributor
timestamp: July 21, 2023, 09:28:42 am
content: Any 6.8V TVS should be fine.

author: shved
author_rank: Regular Contributor
timestamp: July 28, 2023, 03:46:29 pm
content: I've blown up another TC1. Needed to replace and reflash AtMega and remove zeners. Now works as usual.Backstory: I have several transistortester models, both store bought and DIY. Pin-outs are different on some of them. I took checked and discharged cap from an vintage amp I was repairing and mistakenly connected it to the zener (AK) terminals, then I've realized my screw-up(as this is the only model with zener mode) and reconnected the cap as it should be connected (123) terminals. Next thing i know - permanent resistors between terminals no mater what....The moral of the story: Discharge caps before testing! Do not connect anything but zeners and LEDs to KA terminals as this will charge the caps! If cap is big enough both internal and external zeners will not help. The repairs are simple enough, but annoying.Have more than one tester for the job!Hoard test equipment!

author: elecdonia
author_rank: Frequent Contributor
timestamp: July 28, 2023, 08:04:57 pm
content: Quote from: galaga1982 on July 21, 2023, 05:53:01 amI had similar accident with a Transistor Tester.In the original Transistor Tester thread there are discussions about an upgrade with a small relay which totally disconnects the probes from the MCU until the power button is pressed. Additionally, while in the "off" state the relay connects resistors between all 3 probes to discharge capacitors. This is a very reliable protection system as long as one remembers to connect the probes to the capacitor under test while the Transistor Tester is in the "off" state.I intend to add this relay protection mod to the Transistor Tester I use most often on my test bench.(At this point I think I have at least 6 Transistor Testers)

author: galaga1982
author_rank: Contributor
timestamp: July 29, 2023, 05:31:41 am
content: Quote from: elecdonia on July 28, 2023, 08:04:57 pmHello?Can you show me a real picture of the relay protection mod you made? I want to make this circuit, too.In my case, even though there were ZD1 and DZ2 diodes, the VCC and GND of ATMEGA324P were damaged by SHORT.I don't want to break the lovely $20 TESTER with CAPACITOR anymore.

author: galaga1982
author_rank: Contributor
timestamp: July 29, 2023, 06:35:55 am
content: Quote from: madires on July 21, 2023, 09:28:42 amHi madires,I've read this thread several times, removed zd1 and dz2, and hoped it would be no problem, but the sad prediction was never wrong.I connected 3.7 voltage battery, but the screen became very dark, and after a while I had no choice but to look at cell voltage.I think atmega324p is broken. When the resistance of vcc and gnd is measured, a low value of about 50ohm is obtained.Maybe the I/O is damaged by the energized capacitor, but I don't know why the screen got dark.Regarding atmega324p mcu programming,I have Xgecu t48 (upper version of TL866 programmer). I'm trying to program it with 324p mcu using qfp44 to dip40 adapter and I'm wondering if I need an isp connection as well.I'm not used to programming avr microcontrollers. There are many ways like USB-UART, 3V3, etc,but rather than buying another programmer, I would appreciate it if you could tell me how to use the TL866-based programmer I have.Sungmin

author: madires
author_rank: Super Contributor
timestamp: July 29, 2023, 09:58:17 am
content: Sorry, I can't help you with the TL866 based programmer. The universal programmer I have supports ISP and HV parallel programming of ATmegas. ISP is the standard method and the HV mode is used in case the fuses are screwed up and ISP doesn't work.

author: indman
author_rank: Super Contributor
timestamp: July 29, 2023, 01:07:07 pm
content: Quote from: galaga1982 on July 29, 2023, 06:35:55 amNo, you don't need isp in this case. If the qfp44 to dip40 adapter is working properly, you should have no problem programming the ATMega324 and any other controller. ISP is necessary if you are going to program the controller without removing it from the PCB (in the schematic).

author: galaga1982
author_rank: Contributor
timestamp: July 30, 2023, 07:08:35 am
content: Thank you for answer. By the way, if the atmega324p breaks down, does the tc1 screen get dark? The zd1, dz2 diodes have already been removed.

author: madires
author_rank: Super Contributor
timestamp: July 30, 2023, 09:27:44 am
content: Could be a backlight issue. Does the 3.3V LDO for the display output 3.3V?

author: galaga1982
author_rank: Contributor
timestamp: July 30, 2023, 01:30:06 pm
content: I think it's low drop out too, but I'm not sure if it's caused the mcu to fail. There was no back light problem before the disaster.

author: digik
author_rank: Regular Contributor
timestamp: August 07, 2023, 10:27:49 am
content: I have this version:after testing one charged cap is dead. I have dead short betweed D1 terminals.I have removed D1, D2, C3, C25 and C30, same result.I removed 78L05 and is still dead with a short between D1 terminal.Is MCU bad?

author: madires
author_rank: Super Contributor
timestamp: August 07, 2023, 04:15:29 pm
content: Yes, most likely. BTW, that MCU is an LGT8F328.

author: digik
author_rank: Regular Contributor
timestamp: August 07, 2023, 07:11:30 pm
content: is there a reliable way to test if is the MCU?also seems that the LGT8F328 version is the highest specs one but also the only one without schematic available

author: madires
author_rank: Super Contributor
timestamp: August 07, 2023, 07:27:04 pm
content: Power the tester by a lab PSU and look for hot components. Proper testers come with an genuine ATmega.

author: digik
author_rank: Regular Contributor
timestamp: August 08, 2023, 10:27:51 am
content: everything stays cool. is there a schematic for this specific version? btw i have tested everything and no component seems shorted...except the MCU. I will desolder the MCU and see if the short goes away

author: digik
author_rank: Regular Contributor
timestamp: August 10, 2023, 08:40:28 am
content: short is gone after removing the MCU. In the bin the thing goes.

author: acerquax
author_rank: Contributor
timestamp: September 24, 2023, 08:54:29 pm
content: Hello all,my name is HarryI am new here and I am impressed of all this good ideas, repairing this "tiny" tester. Great stuff!!I read this threat very thoughtful, but I am a bit unsure how to handle my killed tester?!I did exact the same as many others:Forgotten to discharge a condensator, tried to measure capacitance on my T7 and "PENG".The result:I switch it on, the display shows as usual Testing.... and after a while it shows some voltage sometimes between Pin 1 and 2 and sometimes between 2 an3 a.s.o.I guess my ATmega324 has got some spike and is death.So I have to replace it, but what do I have to flash, only the 324 or the 15L104 as well?I don't understand the function of the 15L104.Why do I have to flash it as well?Can I get an idea here in this threat where to find an original firmware copy ?Many thanks in advanceHarry

author: madires
author_rank: Super Contributor
timestamp: September 25, 2023, 11:03:25 am
content: If you got a copy of the T7's modified firmware (flash and EEPROM) you would only need to program the replacement ATmega since the STC15L104W still works. The STC15L104W is an additional MCU which controls power and the test button which makes that tester incompatibile with the standard design. The alternative is to go for an OSHW firmware and also reprogram the STC15L104W with an alternative firmware, or to replace it with a simple two-transistor circuit.

author: acerquax
author_rank: Contributor
timestamp: September 25, 2023, 09:50:31 pm
content: Thx for your infos. great!Where can I get a copy of the t7 firmware from?I couldn't read out the firmware from my atmega 324, it was blocked..

author: madires
author_rank: Super Contributor
timestamp: September 26, 2023, 08:33:59 am
content: The Chinese clone manufacturers usually set the lock bits to prevent the firmware being read. I haven't seen any available copy of the T7's modified firmware so far.

author: indman
author_rank: Super Contributor
timestamp: September 26, 2023, 08:54:36 am
content: acerquax,madires, usually the circuit design of the T7 and TC1 clones with the ATmega324 and the STC controller is the same, so the original Chinese firmware can be found on my resourcehttps://yadi.sk/d/yW8xa5NJgUo5zin the folder LCR-TC1/Firmware/OriginalBut since this firmware, apart from the presence of beautiful graphics, has no more advantages compared to m-firmware and k-firmware, and on the contrary, has many bugs and shortcomings, I recommend installing it only to check the functionality of the tester. Chinese firmware it is unsuitable for correct work with most parts.

author: acerquax
author_rank: Contributor
timestamp: September 26, 2023, 12:32:39 pm
content: indman, madires, thanks a lot for your inputsEhmmm...ATmega 324<-->Atmega644 1:1 replaceable? Are there pincompatible for the T7-pcb or do I have to modity the T7 pcb?

author: madires
author_rank: Super Contributor
timestamp: September 26, 2023, 04:33:18 pm
content: Yep, they are pin-compatible.

author: LeWidget
author_rank: Regular Contributor
timestamp: October 03, 2023, 02:27:14 pm
content: Hi all. I was looking to get one of these testers but tossing up between the TC1 & T7. Which one is more useful, reliable, easier to repair if something goes wrong ?

author: acerquax
author_rank: Contributor
timestamp: October 07, 2023, 03:24:41 pm
content: Quote from: LeWidget on October 03, 2023, 02:27:14 pmIn the meantime I have two of these T7, I blowed up one of this devices by trying to measure a charged capacitor () so a huge spike killed the analog input of the MCU!I changed the MCU today and now we will see how good the different firmwares are.No experience with the TC1 but if I understand the threat correct, these pcbs are almost the same.Don't bring too much current into the MCUs 644 or 324 or whatever,the absolute rating for input current of this MCUs are strong limited!Otherwise you need a microscope and a good soldering device and a good idea to get rid of the damaged MCU

author: acerquax
author_rank: Contributor
timestamp: October 08, 2023, 04:40:04 pm
content: With a microscope and a good soldering station I could replace the atmega32x with an atmega644.I could flash the hex-files and eep-files(only test button) which indman suggestedbut after switching on the T7 I see only a white screen for some seconds!Thats it!What do I wrong?Do I have to reflash the 15L104 as well?

author: madires
author_rank: Super Contributor
timestamp: October 09, 2023, 10:10:17 am
content: There are several variants of the T7. Please post a picture of the tester's PCB and also one of the display module (the side with LDO, levelshifter, etc).

author: acerquax
author_rank: Contributor
timestamp: October 09, 2023, 06:07:46 pm
content: Voila'...Thanks mate! (Dankschee)

author: madires
author_rank: Super Contributor
timestamp: October 09, 2023, 07:42:39 pm
content: That one needs a firmware update for U4 (https://github.com/atar-axis/tc1-u4) or a simple two-transistor circuit which replaces U4 (https://github.com/madires/Transistortester-Warehouse/blob/master/Hardware/TC1-Mod.pdf).

author: acerquax
author_rank: Contributor
timestamp: October 10, 2023, 02:53:47 pm
content: Quote from: madires on October 09, 2023, 07:42:39 pmThx mate..!butNo flashing possible.....FTDI USB/UART connected,started stc-isp6,adjusted 12MHz ,opened code file U4.hex--->Download program.....>>> ..checking target MCU....................nothing more!

author: indman
author_rank: Super Contributor
timestamp: October 10, 2023, 02:59:55 pm
content: acerquax, It is not necessary to reprogram U4, remove it from the board and save it to be able to return the factory Chinese firmware. Instead of U4 build a very simple circuit on 2 transistors, which madires suggested. It works much better and more reliably than the U4.

author: madires
author_rank: Super Contributor
timestamp: October 11, 2023, 11:40:54 am
content: ... and the quiescent current is much lower.

author: acerquax
author_rank: Contributor
timestamp: October 17, 2023, 03:38:39 pm
content: .....in the meantime......I built up your transistor replacement U4.What happensThe tester starts with the introduction menue<<<Component Tester>>><<<LCR-TC1 v1.43m>>>then it is displayed for a short timeTesting....Bat 3.9V VCC 4.98Vthen >>>switching offWhat is the functionality of this two transistors?When I push the buttonenable goes high (Pin3) ;PD1 (Pin7) goes low;PD2(Pin8) always Highas long as I see the introduction menueThats it...

author: madires
author_rank: Super Contributor
timestamp: October 17, 2023, 05:24:19 pm
content: What have you set for BAT_LOW? PD1 is the test button input (low active) and PD2 is the power control output (high active). U4's pin 3 (enable) is connected to the boost converter's 'enable' input. When you push the test button Q1 turns on the boost converter via the 'enable' signal. The ATmega is powered and starts running the firmware. One of the first things the firmware does is setting PD2 high. This keeps the 'enable' signal for the boost converter high, regardless of the test button. At the same time PD2 is also used as power source for the button input PD1, generating a high signal when the button isn't pressed. When the button is pressed Q1 turns on and switches Q2 to generate a low signal for PD1.

author: acerquax
author_rank: Contributor
timestamp: October 17, 2023, 10:17:51 pm
content: Thx mate...BAT_LOW?no idea what this means, maybe the problem?!!What I measured, no more high at PD2 after the intro, that means for me no more power state locking and therefore no power for the MCU at all.

author: indman
author_rank: Super Contributor
timestamp: October 18, 2023, 06:20:32 am
content: Quote from: madires on October 17, 2023, 05:24:19 pmMadires,acerquaxuses my modified version of m-firmware 1.43ModEn, which is posted on my yandex disk resource. BAT_LOW is set to a threshold of 3300 and that is not the reason for the shutdown.Firmware 1.43Mod is tested by me personally on a similar TC1 clone and also by a very large number of other people and has shown itself to be very reliable and stable.Toacerquax:1.Check again very carefully how well you soldered the new ATMega644 processor and cleaned the flux afterwards! This is the main reason that causes difficulties and problems for the owners of the device.2.Show me the state of the fuses, which is read by your programmer from ATMega644?ToAll!The forum has 1 global thread "$20 LCR ESR Transistor checker project" which has many different experienced people participating and reviewing, including our esteemed author madires. So I don't see much point in creating several duplicate new threads with questions like "my TC1 or T7 tester doesn't work, what should I do?". Ask your questions about this project in the global thread and you will be answered quickly. And to look through a dozen new branches with the same questions I personally do not have any desire.

author: acerquax
author_rank: Contributor
timestamp: October 18, 2023, 08:21:12 am
content: Thx indman...No problem to swing over to the threat you suggested.I didn't managed the fuses at all!I can't find your suggested firmware... :'([ Attachment Invalid Or Does Not Exist ]

author: indman
author_rank: Super Contributor
timestamp: October 18, 2023, 08:31:55 am
content: acerquaxhttps://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg3578117/#msg3578117

author: indman
author_rank: Super Contributor
timestamp: October 18, 2023, 08:50:13 am
content: What programmer and software are you using?

author: acerquax
author_rank: Contributor
timestamp: October 18, 2023, 06:27:02 pm
content: I checked it with several softwaresAVR Burn-o-matandmyAVR Prog toolMy programmer worked always perfect in different projects! (Arduino,esp32...)

author: Cartel
author_rank: Newbie
timestamp: December 17, 2023, 12:16:52 pm
content: whats it mean when it saysbattery 368mv365mon the screen every test?I barely used this thing and it seemed way off from the lcr-t4.now its more money wasted on china junk

author: madires
author_rank: Super Contributor
timestamp: December 17, 2023, 08:52:48 pm
content: That means the tester measures those voltages between the probe pins and assumes an external voltage source. Typically this is caused by a bad SRV05-4 or by damaged MCU pins. Remove the SRV05-4 and check again.

author: Cartel
author_rank: Newbie
timestamp: December 20, 2023, 07:42:17 am
content: Quote from: madires on December 17, 2023, 08:52:48 pmI have a blue version. U5 gets very hot after just 1 test.

author: indman
author_rank: Super Contributor
timestamp: December 20, 2023, 07:49:50 am
content: Cartel,remove D1 and D2 from the PCB and turn on the tester without these parts. If nothing changes, the main controller is damaged.All of these nuances are chewed up in detail in this thread several times on every page.

author: iv3wjr
author_rank: Newbie
timestamp: December 29, 2023, 02:28:25 pm
content: Hi to all,first of all let me say THANKS to all of you for this amazing thread, I've learned a lot from reading.I'm owner of a TC-V2.12k. Mine worked fine until I forgot to charge the battery for... years. Now I replaced the dead battery with a new LP524558 3.7V 1450mAh battery. After full charge (red led, than green) pressing the start button the device boots, the screen turns on but I see only the message "Charge the battery" with a (wrong) [ Vbat = 2.26V ] message. No way to calibrate, only that message.Now the question: is there a way to "reset" the device or to "force" a new calibration?Thanks for your time.Bob

author: csuhi17
author_rank: Frequent Contributor
timestamp: December 29, 2023, 02:48:38 pm
content: Quote from: iv3wjr on December 29, 2023, 02:28:25 pmHi, have you measured the voltage of the replacement battery, is the device really fully charged?Can you use it while charging?

author: iv3wjr
author_rank: Newbie
timestamp: December 29, 2023, 03:04:02 pm
content: Sorry, forgot to add the battery voltage: 4.16V at the battery pins, after full charge (green led) and charger disconnected. Charging or not makes no difference, cannot get rid of the message after power on/off several times.

author: njsw88
author_rank: Contributor
timestamp: February 02, 2024, 02:41:23 pm
content: i know this is an old post but i have the same issue with my TC-1 multi-function tester, but my pcb board, is very different than the one in the post, i have attached the pic but i found that C11 and C12 seam to be ok, but i found that there is a short on C2 , is this a new fault or should i still replace the C11 , C12 and the C2, and what should i replace them with as i do not know what they are ? please help as im new to electronic any help at all will be appreciated, thankyou shane from Brisbane Queensland Australia

author: madires
author_rank: Super Contributor
timestamp: February 02, 2024, 05:19:33 pm
content: Remove C2 and check if it's really shorted or if the short is somewhere else. BTW, your tester has a fake ATmega (looks like an APT32F172K8T6).

author: njsw88
author_rank: Contributor
timestamp: February 04, 2024, 06:41:41 am
content: tock out the C2 and no difference still short some where

author: njsw88
author_rank: Contributor
timestamp: February 04, 2024, 07:17:05 am
content: hi again , what is a good multi-function tester to buy i was looking at the " MESR-100 ESR Capacitance Ohm Meter Capacitance Resistance Tester" or is there a better on with the same sort of display as the TC1thankyou in advance for your replies shane

author: MarkMLl
author_rank: Frequent Contributor
timestamp: February 04, 2024, 09:05:41 am
content: EEVBlog still advertises budget multimeters: perhaps we also need a definitive recommendation for a budget component tester with a stable design that the community can support happily.MarkMLl

author: madires
author_rank: Super Contributor
timestamp: February 04, 2024, 09:28:03 am
content: AY-AT (aka GM328A) with a DIP ATmega (best bet at the moment to avoid alternative MCUs).

author: njsw88
author_rank: Contributor
timestamp: February 04, 2024, 10:48:29 am
content: yes that would be awesome

author: njsw88
author_rank: Contributor
timestamp: February 04, 2024, 10:49:55 am
content: yes i will thanks

author: MarkMLl
author_rank: Frequent Contributor
timestamp: February 06, 2024, 10:07:18 am
content: Quote from: madires on February 04, 2024, 09:28:03 amBut from where? Is there somebody reputable like Farnell ** who will commit to supplying a stable design?** Noting of course their extortionate small-order handling chargeMarkMLl

author: njsw88
author_rank: Contributor
timestamp: February 07, 2024, 03:12:28 am
content: what about RS Components

author: njsw88
author_rank: Contributor
timestamp: February 07, 2024, 10:06:14 am
content: what i have found now , that if i put 3v on the VCC of the CH340N chip which is located at U3 on my PCB board which i show on my other post it starts up and i have no more shorts on C2, do you think that this is the problem ?

author: madires
author_rank: Super Contributor
timestamp: February 07, 2024, 11:08:09 am
content: How much current is drawn on that external 3V? Are CH340N and C2 connected via some trace?

author: njsw88
author_rank: Contributor
timestamp: February 08, 2024, 09:17:17 am
content: 3v 1amp

author: madires
author_rank: Super Contributor
timestamp: February 08, 2024, 09:39:41 am
content: Such a high current is an indication of a shorted component. You could use that and look for a hot component (most likely an MLCC).

author: njsw88
author_rank: Contributor
timestamp: February 08, 2024, 02:12:45 pm
content: ok thankyou i will check

author: MarkMLl
author_rank: Frequent Contributor
timestamp: February 09, 2024, 09:53:49 am
content: Quote from: njsw88 on February 07, 2024, 03:12:28 amThey unilaterally cancelled half of one of my orders after assuring me on the 'phone that they were able to fill it. 'Nuff said? :-/MarkMLl

author: njsw88
author_rank: Contributor
timestamp: February 09, 2024, 01:11:45 pm
content: hi again guys ok the Volts are 3.2v and the amps are 0.3 on the U3 CH340N chip it cam on and stayed on, but i notice that the MEGA928P got hot but could not feel any other chips getting hot, any ideas ? or is it the MEGA928P chip that needs replacing, thanks Shane

author: madires
author_rank: Super Contributor
timestamp: February 09, 2024, 03:03:29 pm
content: Another common problem is a bad SRV05-4 (U6 in your case, near the ZIF). If it's shorted it would also impact the MCU. Remove U6 and see if it helps.

author: njsw88
author_rank: Contributor
timestamp: February 10, 2024, 04:42:55 am
content: ok thankyou i will give it a go thanks again

author: spacebiscuit
author_rank: Newbie
timestamp: February 21, 2024, 06:29:20 pm
content: Can I jump in - I have the T7 - was working fine but I think I forgot to discharge a capacitor. Tried to turn on the tester today and it is dead - led comes on if I plugin the usb.I've open it up and I get open circuit on c3, c25, c9 and r15 - is that my issue?I have this model (taken from page 11)Thanks in advance.

author: carl1961
author_rank: Contributor
timestamp: February 22, 2024, 03:21:08 am
content: Quote from: spacebiscuit on February 21, 2024, 06:29:20 pmas on page 11 looks like same as one @madires said has a LGT8F328 MCU I have the same board, but still working, I never tried dumping the firmware, most likely useless to try as they seem to lock them from dumping.

author: spacebiscuit
author_rank: Newbie
timestamp: February 26, 2024, 08:43:36 pm
content: So is this only good for the recycling/trash now?

author: njsw88
author_rank: Contributor
timestamp: March 02, 2024, 02:41:08 pm
content: Can any one tell me what this chip is or what is its equivariant, as i cant find anything on the net about this chip.any help thankyou

author: indman
author_rank: Super Contributor
timestamp: March 02, 2024, 04:45:22 pm
content: njsw88, this is a microcircuit SD6210A

author: njsw88
author_rank: Contributor
timestamp: March 03, 2024, 05:30:59 am
content: thankyou so much

author: dlkeng
author_rank: Newbie
timestamp: March 06, 2024, 01:25:49 pm
content: I recently received a LCR-TC1 tester from AliExpress and it is the same blue board one with the LGT8F328 MCU shown on page 11 and replies #320 and #321.If anyone is interested, I have reverse-engineered its schematic and have attached it here.

author: MarkMLl
author_rank: Frequent Contributor
timestamp: March 08, 2024, 08:41:30 am
content: Quote from: dlkeng on March 06, 2024, 01:25:49 pmCould we have a robust link to that on AliExpress, since there are many sellers represented with different products?MarkMLl

author: dlkeng
author_rank: Newbie
timestamp: March 08, 2024, 12:45:08 pm
content: I don't know that there is such a thing as a robust link to an AliExpress product as each time I have returned to the page of the item I ordered, it seems to have a different price! (it was about $14 when added it to my shopping cart, but I was charged $11.73 for it and it is now advertised as $9.57)Anyway, the link to the page I ordered from seems to be:https://www.aliexpress.us/item/32611989538.html

author: MarkMLl
author_rank: Frequent Contributor
timestamp: March 11, 2024, 01:31:33 pm
content: Quote from: dlkeng on March 08, 2024, 12:45:08 pmThat certainly works at the moment.Bear in mind that price will depend on exchange rates, which will depend on multiple countries' whim.I'd add that it's interesting that the photos on that page show that the cased variant has a USB connector for charging, while the uncased variant has a clip for a PP3 battery. It's almost as though they're intentionally preventing anybody swapping in the cheaper board when they blow the cased meter...MarkMLl

author: SA
author_rank: Contributor
timestamp: March 11, 2024, 10:32:41 pm
content: Quote from: Nokeshas on July 03, 2023, 10:20:02 amCan you please share the hex and epp files? I also have got TC1 with atmega328p DIP. Fried the MCU.Thanks in Advance

author: galaga1982
author_rank: Contributor
timestamp: April 02, 2024, 01:56:53 am
content: Thyristor measurement error?Hello?I got a lot of information from here and helped me to repair TC1 lcr-meter well. However, I have a new question.When measuring Thyristor with TC1 lcr-meter, has anyone experienced it being marked as PNP or NPN transistor instead of accurately? The Thyristor I measured was common TYN610 (ST), 5P4M (NEC).Another strange thing is that after setting DMM in diode measurement mode and connecting + probe(red) to Cathode and - Probe to Anode to check for failure, the resistance value is infinite, and when I short Gate and Anode, the current is not maintained, and it is immediately released. If it is normal, it is said that this should hold current. Is my Thyristor failure measurement method wrong?Thank you.

author: Kim Christensen
author_rank: Super Contributor
timestamp: April 02, 2024, 02:15:46 am
content: Your Thyristor needs a minimum hold current to stay on. It also has a minimum trigger current. For the TYN610, the trigger current could be up to 15mA and the hold current up to 30mA. The DMM and TC1 probably doesn't provide enough current for that. Build a simple test circuit instead. (Adjust lamp size and R1 for your Thyristor) :

author: galaga1982
author_rank: Contributor
timestamp: April 02, 2024, 05:13:24 am
content: Thank you. I briefly thought about the gate-triggering current, and I think that's right. I'll try it and let you know the result.

author: algorithm
author_rank: Regular Contributor
timestamp: April 05, 2024, 04:35:30 pm
content: Having had a tc1 since before this thread was started, I find the device useful often in many ways, double checking. Though everytime I reach to use it lately its dead even though it was fully charged. Sometimes in as little as 1 week. Using a usb power meter it saysitsdrawing between 18-24mA , even when dark/off.According to others posts this is in line with shorted c6/c7.Im keen to replace these, though hesitant as I dont know the correct capacitances.Anybody know what value those 2 mlccs are?Hoping I can properly fix this rather than hacking a dipswitch into the battery. Though with no battery it draws 0mA

author: madires
author_rank: Super Contributor
timestamp: April 05, 2024, 04:47:00 pm
content: They shouldn't be critical, maybe 100nF?

author: indman
author_rank: Super Contributor
timestamp: April 05, 2024, 04:53:45 pm
content: Quote from: algorithm on April 05, 2024, 04:35:30 pmWhy don’t you admit that there may also be a leak in capacitors C2-C5?You need to check all the capasitors that are in the battery circuit. Their capacitance, asmadirescorrectly noted, is not particularly important, but usually in such circuits, to eliminate possible interference and noise, several capacitors of different capacitances are placed next to each other, for example 1nF, 100nF, 1mkF, 5-10mkF

author: algorithm
author_rank: Regular Contributor
timestamp: April 05, 2024, 05:27:09 pm
content: Quote from: madires on April 05, 2024, 04:47:00 pmI halfway expected that but also didnt want to assume and find out I was wrong.Thats perfect if so because I have a tape of 100nf suitable. Thanks for chiming in.Quote from: indman on April 05, 2024, 04:53:45 pmWell I can dig that, just going off the past 14 pages. I saw multiple posters stating that draw was fixed by replacing 1 of those 2. Though you are right, im not sure what the cause is.I also read that could be a fried mcu or shoddily programmed mcu. But id hope I could get lucky and only need to replace a few caps.Found a parts list for the gm328r, not sure if that is applicable but that had 100uF and 100nf.Wish the tc1 schematic had values. But yeah testing c6 and c7 shows like 6uF but c7 shows 0uF randomly (with good contact on probes )

author: BILLPOD
author_rank: Frequent Contributor
timestamp: April 05, 2024, 06:40:12 pm
content: Quote from: algorithm on April 05, 2024, 04:35:30 pm

author: algorithm
author_rank: Regular Contributor
timestamp: April 05, 2024, 06:56:55 pm
content: To answer my own question c7 is 10uF, c6 is 100nF.Confirming the wise topological words from indman pertaining to interference/noise suppression.Seems c6 was shorting. Though after replacing it its still drawing 18mA.EDIT: im an idiot. I was trusting that cheap usb power meter.After thinking about it I realized that I was only seeing the current consumption on charging...And after I still saw 18mA draw after replacing c6, I left it on charge until full.Upon full charge the power meter declared 0.00mA consumption though.So I tried to test the draw with a multimeter in series with the battery +.I got 2.xx mA when powered. After timeout it dropped to 0.10mA (100 microamps) screen dark. After 10-15 seconds it drew 0.00mA.So another satisfied customer after replacing c6/c7. (Though I didnt change c7 as it tested good out of circuit). I just wish I would have tested the consumption correctly with a dmm before replacing the cap.Rather than lazily trusting the usb power meter. I definitely know something was wrong because it would lose a full charge in a week.For fun and irony I used the tc1 to test c6 and it would show 95nf 0.17k esr. If I hit test again it would read "no unknown or damaged part", repeating the test repeated the result. So yeah if your capacitor randomly drops to 0.00uF while testing worth suspicion.I might have avoided the toggle switch mod.Quote from: BILLPOD on April 05, 2024, 06:40:12 pm

author: galaga1982
author_rank: Contributor
timestamp: April 20, 2024, 07:13:21 am
content: Hi,As you said, a simple circuit for thyristor test was constructed. The LED turns on when you close the gate and anode as shown in the picture. And even when opened, my 5P4M thyristor seems to be normal as it remains on.By the way, why is thyristor not accurately marked on the LCR meter as shown in the picture? I'm using LCR-TC1 2.12K FIRMWARE, and this wrong information was the same for other types of monochrome LCR meters. It would be very appreciated if madires, indman or anyone else could answer this symptom.Regards,

author: indman
author_rank: Super Contributor
timestamp: April 20, 2024, 07:35:17 am
content: galaga1982, The tester can test parts with a voltage of maximum 5V and a maximum current of only 5-7mA. This is stated in the author's instructions. For your 5P4M Gate-trigger Current(Igt) is 10mA, so the tester cannot create it and reliably open the thyristor. Therefore, thyristors and other parts that require higher voltage and current cannot be detected correctly. We must always remember this!

author: madires
author_rank: Super Contributor
timestamp: April 20, 2024, 09:22:04 am
content: The 5P4M has a maximum trigger current of 10 mA and a typical holding current of 10 mA. That's is bit more than the tester can provide.

author: gmc
author_rank: Regular Contributor
timestamp: May 27, 2024, 09:22:20 am
content: Purchased a TC1 from Alix and also received a blue version with U1. The numbers on the chip have been erased but guessing its a LGT8F328Attaching a photo for reference.Is there any firmware dump for this version?

author: madires
author_rank: Super Contributor
timestamp: May 27, 2024, 10:05:42 am
content: Yes, the MCU's pinout matches a QFP48L LGT8F328. So far I haven't seen any firmware dump for that one.BTW, jm_araujo replaced the LGT8F328 of his T7 with an ATmega328:https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg5518618/#msg5518618

author: SA
author_rank: Contributor
timestamp: May 29, 2024, 05:49:11 pm
content: I have fried my TC1 with charged capacitor. The MCU also fried. My TC1 comes with ATMega328p DIP IC. I am not an expert in but if I could get complied code, I would be able to fix it. Please help me

author: madires
author_rank: Super Contributor
timestamp: May 29, 2024, 07:48:56 pm
content: Have you already tried with U2 and D1 (weak input protection) removed?

author: Kim Christensen
author_rank: Super Contributor
timestamp: May 29, 2024, 08:07:21 pm
content: Quote from: SA on May 29, 2024, 05:49:11 pmThere are compiled versions out there. But on another note, while a pin or two might be fried, you may still be able to read the Flash and eeprom. (You need both) Then simply write it to a new chip.Depends on whether the chip has copy protect enabled or not.

author: slash14
author_rank: Newbie
timestamp: May 30, 2024, 08:47:53 pm
content: Hello Everyone,Sorry for being a little off topic here, but this picture caught my attention.Quote from: digik on August 07, 2023, 10:27:49 amI was intending to play a bit with one of these component testers (first by attempting to flash an original, latest firmware, just to try).So got my self a T7, which has exactly this blue PCB.And I was wondering: the ISP connection (at the very top of the picture if not mistaken) seems to have only 5 pins, instead of the usual 6.Am I missing something?Like on the picture above, none of the pins are labelled on mine, apart from the +5VDC and G(nd) pins.Any ideas about what are the 3 other pins, and why only 3 and not 4?The MCU marking on my unit has been erased, I doubt it is a genuine Atmel thing. Could be a LGT8F328 of some sort but who knows. Therefore I can't really find out the pins from a MCU datasheet.Thank you.

author: madires
author_rank: Super Contributor
timestamp: May 30, 2024, 09:17:47 pm
content: Yes. that's an LGT8F328. Pin 21 is SWD which is also part of the SWD programming interface (Gnd, Vcc, SWD, SWC, Reset). Pin 21 of a genuine 32-TQFP ATmega328 would be Gnd.

author: gobi2000
author_rank: Newbie
timestamp: June 15, 2024, 01:14:18 am
content: Quote from: madiresHave you found the pin out of this PCB?

author: madires
author_rank: Super Contributor
timestamp: June 15, 2024, 08:17:36 am
content: No, neither do I have that clone nor its schematic.

author: gobi2000
author_rank: Newbie
timestamp: June 15, 2024, 03:29:38 pm
content: I measured a capacitor, which was discharged behind the multi meter and is now dead, so I wanted to know if it had any protection.

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 15, 2024, 04:34:56 pm
content: Quote from: gobi2000 on June 15, 2024, 03:29:38 pmIf you have the same device asslash14 postedthen the protection device is probably D2 on that PCB which is similar tothe SRV05-4 by ON-semi.D1 also looks to be part of the protection circuitry.

author: SA
author_rank: Contributor
timestamp: June 18, 2024, 11:03:42 pm
content: Quote from: madires on May 29, 2024, 07:48:56 pmYes, I replaced the U2 and D1 is fine.After replacing it came to life but showing cell from 1-2 pin. The mcu also heating. So I have to replace the atmega328p. But I need the compiled code and Fuse bits. I will be greatful if you please help me.

author: SA
author_rank: Contributor
timestamp: June 18, 2024, 11:07:03 pm
content: Quote from: Kim Christensen on May 29, 2024, 08:07:21 pmCan you please provide the link of the compiled code for tc1 with dip Atmega328p?? And where to find the fuse bits??I have tried to read but the mcu is read protected

author: madires
author_rank: Super Contributor
timestamp: June 19, 2024, 08:39:32 am
content: Quote from: SA on June 18, 2024, 11:03:42 pmIn case you're looking for an OSHW firmware:https://github.com/madires/Transistortester-Warehouse

author: SA
author_rank: Contributor
timestamp: June 20, 2024, 01:09:21 am
content: Quote from: madires on June 19, 2024, 08:39:32 amI am unable to find suitable code for my device.This one is my device:

author: madires
author_rank: Super Contributor
timestamp: June 20, 2024, 06:52:50 am
content: Sorry, I don't provide compiled firmwares.

author: tedris
author_rank: Contributor
timestamp: June 23, 2024, 05:15:34 pm
content: hi ihave t7 I measured without discharging the capacitor. malfunctioned but i notice that 7805 in 0v so no give 5v. and i connect 5v 7805 its run but not measured. i push button bur show same power voltage how solve this?not measuring why?

author: madires
author_rank: Super Contributor
timestamp: June 23, 2024, 07:03:05 pm
content: Please post a picture of the PCB to help figuring out which specific model you have and if it got a genuine ATmega.

author: tedris
author_rank: Contributor
timestamp: June 24, 2024, 04:17:33 pm
content: My board picture this thanks

author: madires
author_rank: Super Contributor
timestamp: June 24, 2024, 05:13:00 pm
content: Your T7 is an early version and has a genuine ATmega. Remove ZD1 (6.8V TVS) and DZ2 (SRV05-4) and try again. If the tester still shows "Cell" then the ATmega is damaged.

author: tedris
author_rank: Contributor
timestamp: June 26, 2024, 09:18:34 pm
content: hi i try it but not work it same. if i bought this chip is it run? it adapt my board? thanks for help sory my english is bad.

author: madires
author_rank: Super Contributor
timestamp: June 27, 2024, 08:24:41 am
content: You can replace the ATmega and program an OSHW firmware. You'll also need to reprogram U4 or replace it with a simple two-transistor circuit.

author: indman
author_rank: Super Contributor
timestamp: June 27, 2024, 08:52:41 am
content: Quote from: madires on June 27, 2024, 08:24:41 ammadires,tedrishas an ATmega32 in the screenshot, it is not supported in the OSHW project.tedris,you can only replace a damaged controller with an ATmega324 or ATmega644.

author: MarkMLl
author_rank: Frequent Contributor
timestamp: July 05, 2024, 08:52:22 am
content: Quote from: madires on June 19, 2024, 08:39:32 amSince this is very much an FAQ, I suggest that that page could usefully have some specimen photos of supported boards possibly with a couple of arrows showing people what to look for.MarkMLl

author: madires
author_rank: Super Contributor
timestamp: July 05, 2024, 09:34:32 am
content: Something likehttps://github.com/madires/Transistortester-Warehouse/blob/master/Documentation/English/Clone-Comparison-Chart.pdf?

author: MarkMLl
author_rank: Frequent Contributor
timestamp: July 08, 2024, 12:46:40 pm
content: In the main repo I see a fairly prominent link tohttps://github.com/kubi48/TransistorTester-source/blob/master/picture-link.pdfParticularly now that somebody has usefully raised a question based on a tester that /can't/ be upgraded from your repo I think that you could usefully have a "These are the testers known to work" link to the PDF you gave.MarkMLl

author: tedris
author_rank: Contributor
timestamp: July 12, 2024, 11:55:06 am
content: Hello, I bought 3 atmega324pa chips, which file will I write to them when they arrive? can you send a link?

author: madires
author_rank: Super Contributor
timestamp: July 12, 2024, 12:43:39 pm
content: Regarding the additional control MCU U4 (STC15L104W) there are two options:- reprogram:https://github.com/atar-axis/tc1-u4- replace with two-transistor circuit:https://github.com/madires/Transistortester-Warehouse/blob/master/Hardware/TC1-Mod.pdfFor m-firmware download the latest version fromhttps://github.com/madires/Transistortester-Warehouse/tree/master/Firmware/m-firmwareand use the settings listed in the Clones file (TC-1, old variant). Compile the firmware and program firmware and EEPROM. And don't forget to set the fuse bits.

author: tedris
author_rank: Contributor
timestamp: July 13, 2024, 03:19:58 pm
content: Thanks What is the difference between these two options? Which is better? practical? Which one can I use?

author: madires
author_rank: Super Contributor
timestamp: July 13, 2024, 04:50:52 pm
content: The two-transistor circuit mod requires some soldering and decreases the quiescent current to about 5 µA. Reprogramming the STC15L104W takes less effort but the tester still has a high quiescent current (you could add a switch).

author: tedris
author_rank: Contributor
timestamp: July 13, 2024, 06:38:32 pm
content: "tester still has a high quiescent current (you could add a switch)." i dont understand. this Thank you for your help. How is this a problem for me? What is the harm? Is it enough for me to go back to its old self? I will be careful not to make the same mistake again (testing without discharging the capacitor).

author: madires
author_rank: Super Contributor
timestamp: July 13, 2024, 07:22:55 pm
content: With the STC15L104W the tester has a high quiescent current which drains the battery in a few months. To mitigate this you can add a simple switch in series with the battery.

author: SA
author_rank: Contributor
timestamp: July 14, 2024, 05:19:54 am
content: Where to find the suitable fuse bits??

author: madires
author_rank: Super Contributor
timestamp: July 14, 2024, 08:45:16 am
content: For m-firmwmare: edit Makefile (MCU, clock, programmer) and run 'make fuses'

author: tedris
author_rank: Contributor
timestamp: July 27, 2024, 04:17:56 pm
content: Hi i buy atmega324pa and i use usb programmer with STC15L104W but not upload why? maybe in software chip not use? is there software adaptape this?

author: madires
author_rank: Super Contributor
timestamp: July 27, 2024, 05:11:14 pm
content: Have you followed the guide onhttps://github.com/atar-axis/tc1-u4?If the STC15L104W can't be programmed maybe it's also also bad. In this case go for the two-transistor circuit modification.

author: tedris
author_rank: Contributor
timestamp: July 27, 2024, 07:31:52 pm
content: Hello, I don't understand, my Atmega processor is faulty, I will install software on it. Why am I dealing with stc15l104w? In the video I saw on the net, it was loading the Atmega processor. I tried as in the link provided, but I could not write stc in any way. I don't understand the other 2 transistor thing, it would be easier if there was a video or a card video. Thank you for your patient help.

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 27, 2024, 07:46:37 pm
content: tedris, if you want to program your Atmega processor, then you need to connect the programmer to J4 instead!

author: tedris
author_rank: Contributor
timestamp: July 27, 2024, 07:54:30 pm
content: What will the connection pins be like? Can this be done with a programmer?

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 27, 2024, 10:14:43 pm
content: Not 100% sure, but I think this is the pinout for J4. (Got pinout from a TC1 schematic) Double check by ohm metering between J4 and the Atmel MCU.(Reset, SCK, MISO, 5V, MOSI, GND)What I did to program my TC1 was connect Reset, SCK, MISO, MOSI & GND to the programmer. Then I temporarily jumpered out the test button to keep the unit powered up during programming.

author: tedris
author_rank: Contributor
timestamp: July 28, 2024, 10:47:16 am
content: I am using win11, could this be the reason? Were you able to do it in win11?

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 28, 2024, 03:37:00 pm
content: I used AVRDUDE on a Win10 machine using it's legacy serial port connected toa crude programmerthat I temporarily built on a breadboard. (That programmer does not work with a USB --> Serial adapter)Why? Because I'm cheap and haven't used Atmel chips for anything else.

author: tedris
author_rank: Contributor
timestamp: July 28, 2024, 05:49:08 pm
content: Can you send a picture? How did you do this, what did it look like? I bought 3 atmega324pa chips thinking that the legs would be short again. However, both programming it and finding the software is a serious problem. There is no software for T7, it will not return to its original state, I have no idea if other versions will work.

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 29, 2024, 02:28:25 am
content: Sorry, I've already disassembled the breadboard and didn't take any pictures at the time. But it wouldn't have been much to see anyway. I simply builtthe programmeron the breadboard and connected it to my TC1 via grabber clips. A very temporary setup. I complied the binaries using WinAVR.

author: tedris
author_rank: Contributor
timestamp: August 06, 2024, 03:33:02 pm
content: Hello, I couldn't find how to make program settings and how to make upload settings. I connect to Atmega and it uploads but a white screen appears, I think there is a special setting that I need to choose.

author: madires
author_rank: Super Contributor
timestamp: August 06, 2024, 04:09:15 pm
content: You can ignore that when using a quartz crystal. That 'oscillator calibration byte' is an adjustment value for the internal RC oscillator.

author: tedris
author_rank: Contributor
timestamp: August 06, 2024, 05:10:47 pm
content: https://github.com/Ho-Ro/ComponentTesterI think I need to edit and compile the file here with ready-made settings according to my own device. Is there a similar video about this? I don't understand how to do it. Is there a chance to compile in Atmel studio? I'm using Windows 10.

author: Kim Christensen
author_rank: Super Contributor
timestamp: August 06, 2024, 08:12:47 pm
content: Don't forget that you have to program 3 things in the atmega324pa:FusesFlash memoryEEPROM memoryIf you forget to program the EEPROM memory, then you can also get a white screen or other problems.

author: tedris
author_rank: Contributor
timestamp: August 07, 2024, 08:09:29 pm
content: When I compile the code, 2 files are created. One is ComponentTester.hex and the other is ComponentTester.eep. I load both of them. I saw that everyone has set the fuse settings differently. I don't understand what my setting should be?

author: SA
author_rank: Contributor
timestamp: August 29, 2024, 02:59:13 pm
content: Does the IR Decoder should look like this? Is it possible to get Hexadecimal code?

author: madires
author_rank: Super Contributor
timestamp: August 29, 2024, 04:46:11 pm
content: It's an unsupported protocol:Quote

author: SA
author_rank: Contributor
timestamp: August 29, 2024, 06:54:02 pm
content: I have tried more than 20 remote. I think the problem is firmware related. Can you please check that... Also compiler output shows this.. (I tried 1.45m, 1.47m, 1.48m,1.53m)

author: madires
author_rank: Super Contributor
timestamp: August 29, 2024, 07:38:33 pm
content: I've checked the IR protocol detection with tons of remote controls and different Transistortesters over the years. It's working fine. However, your tester seems to have a clock issue. The start pulse/pause periods of 172 and 85 (* 50 µs) point to the NEC protocol which is 9 ms (179 * 50 µs) and 4.5 ms (89 * 50 µs). The protocol detection allows some margin for the timing, but the offset is too large in this case. The MCU clock looks to be a bit slow. Have you set the ATmega's fuse bits to use the external quartz crystal instead of the internal RC oscillator? You can ignore the compiler warnings.

author: SA
author_rank: Contributor
timestamp: August 29, 2024, 08:18:56 pm
content: Low fuse 0xF7High fuse 0xD9Extend fuse 0xFCAtmega328pis it right??

author: madires
author_rank: Super Contributor
timestamp: August 29, 2024, 08:57:26 pm
content: That looks right. Still, the MCU clock is the most probable cause, especially since none of your remote controls were detected. The timing of a single remote control might be off, but not all.

author: SA
author_rank: Contributor
timestamp: September 03, 2024, 02:36:03 am
content: After twiking for a long time I am still unable to make the the IR decoder to work properly. But that is not a big problem. Everything else works fine. But when no component is tested it shows Parasitic capacitance ranges from pf to 100uf even after self test and adjustment. Is that also for the MCU clock issue??

author: madires
author_rank: Super Contributor
timestamp: September 03, 2024, 09:07:09 am
content: No, that could be a power supply issue (unstable Vcc).

author: ssimic71
author_rank: Newbie
timestamp: January 21, 2025, 06:04:49 pm
content: Hi guys, what is wrong with my LCR TC1? It shows unreadable number in measurements, like in the given figure.tnx,Sasa

author: madires
author_rank: Super Contributor
timestamp: January 21, 2025, 06:23:04 pm
content: Was it working before? Did it start suddenly or became worse with time?

author: ssimic71
author_rank: Newbie
timestamp: January 21, 2025, 06:26:10 pm
content: That how it was when I first turn on. Until now, I tryed just to calibrate it, and that was succesful. Although, during calibration, also showed this peculear numbers in percentages.

author: madires
author_rank: Super Contributor
timestamp: January 21, 2025, 06:52:37 pm
content: In case the tester works fine besides the weird digits it could be a bad firmware. Since the tester is new I would ask the seller for a replacement.

author: ssimic71
author_rank: Newbie
timestamp: January 21, 2025, 07:23:35 pm
content: It was bought from Aliexpress, the seller is informed about the problem, but I do not expect miricle.The idea of refreshing firmware is ok to me. Could you please direct me how to upgrade, and where to find latest files.Thank you very muchSasa

author: madires
author_rank: Super Contributor
timestamp: January 21, 2025, 07:41:18 pm
content: That depends on the specific model you have. Current models come often with an alternative MCU, making it hard to get any firmware. Genuine ATmegas are supported by the two OSHW firmwares. Please post a picture of the PCB and I might be able to identify the MCU type.

author: ssimic71
author_rank: Newbie
timestamp: January 22, 2025, 08:15:40 pm
content: Here are the pictures, there are no markings on mcu.

author: madires
author_rank: Super Contributor
timestamp: January 22, 2025, 08:51:14 pm
content: Looks to be an LGT8F328 (one of the alternative MCUs), i.e. not supported by the OSHW firmwares.

author: ssimic71
author_rank: Newbie
timestamp: January 22, 2025, 08:54:16 pm
content: Tnx for clarifying.

author: wickedrc
author_rank: Newbie
timestamp: February 05, 2025, 11:46:23 am
content: Hi Guys, and congratulations for this useful forum!I've in trouble with a TC1 tester (version with ATMEGA324PA)It's been broken after a check of a charged capacitorI've check it, and I've found broken DZ2 and U1.I've changed them, now the tester starts, but I've backlit blank screenCan someone explain how to flash the U1?I've already bought a USBasp-H6P interface, and I've soldered a connector to tester PCB (as in picture)Thank you so much!

author: vinhlg
author_rank: Newbie
timestamp: February 09, 2025, 09:24:53 pm
content: Hello all,Does anyone have the schematic diagram of this TC1 version?My TC1 broken, LCD display is total black. When I press "Start" L1 becoming very hot. It seems a short-cirtcuit somewhere?Any advices? Thanks.--- update ---I think I found the reason: U1- LGT8F328 is dead - almost short circuit between PIN 4 (VCC - 5V) and PIN 5 (GND). Removed U1 and I have light on display - (of course nothing).It was my mistake: I check capacitor during charging the battery of LC1 - because I saw low voltage.Lesson learned.Solution is replacement of U1 and reprogramming it. I think.

author: madires
author_rank: Super Contributor
timestamp: February 10, 2025, 10:56:01 am
content: ... if you're able to find the firmware for the LGT8F328. That MCU isn't supported by the OSHW firmwares (only ATmega).

author: madires
author_rank: Super Contributor
timestamp: February 10, 2025, 11:00:15 am
content: Quote from: wickedrc on February 05, 2025, 11:46:23 amPlease search the web for 'programming ATmega' and you'll find tons of tutorials.

author: sanjeevjain
author_rank: Newbie
timestamp: March 30, 2025, 11:37:26 am
content: My LCR TC1 tester always show zener diode on screenSelf Calibration and IR function is working, it battery got too much heated,

author: madires
author_rank: Super Contributor
timestamp: March 30, 2025, 03:01:53 pm
content: IIRC, the modified firmware runs the Zener check after performing the normal probing. Possibly there's something wrong with the circuitry for the Zener check. Does the tester display the Zener voltage? Does it stay about the same or change wildly?

author: littlebalup
author_rank: Newbie
timestamp: July 15, 2025, 12:46:19 pm
content: Hello guys,I unfortunatly fried my T7 tester with an old cap... it blown the SRV05-4 and damaged the Atmel MCU (PA0 shorted to GND).I'd like to repair it by replacing the Atmel chip. Now comes the question of flashing a new firmware. The original chip was bit locked so no way to dump it.I tried the 1.55m with the settings I guessed was the more appropriated to my model (7.12. Multifunktionstester TC-1 or T7 newer variant with ATmega324, 16 MHz). It kind of work (screen) but the test button must constantly be pressed.My model is the one distributed by jot-it :https://joy-it.net/files/files/Produkte/JT-LCR-T7/JT-LCR-T7_Manual_2023-09-21.pdfThe board is the same as this one with "FNIRSI-4A10" marking :https://www.eevblog.com/forum/testgear/tc1-lcr-meter-transistor-tester-fix/msg4349419/#msg4349419I didn't found a matching schematic so I managed to create it to have a better view of what's going on:https://www.dropbox.com/scl/fi/nhep7nofblowvybj1coy1/joy-it-LCR-T7-FNIRSI-4A10-Schematic.pdf?rlkey=cwgv53vsnv0slwwttjkvneh8d&dl=1It may be not 100% accurate. Specially I don't really understand how the test button is working in conjuction with Q1,Q2 and Q3. What is the role of U8. And the U6 and U7 circuitry looks weird compared of what I seen on other clone schematics.So, please comment and give me some clues of the configuration I need for the firmware.

author: indman
author_rank: Super Contributor
timestamp: July 15, 2025, 01:08:35 pm
content: https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg5369153/#msg5369153

author: Proxy64
author_rank: Regular Contributor
timestamp: July 15, 2025, 01:51:35 pm
content: Hi guys,CH341A seems to be supported by avrdude,but how to setup in the Makefile, especially for options ?# CH341A ProgrammerPROGRAMMER = ch341aPORT = /dev/tty.usbserial-1410 #(MacOs)OPTIONS =Thank you

author: madires
author_rank: Super Contributor
timestamp: July 15, 2025, 02:04:48 pm
content: Quote from: littlebalup on July 15, 2025, 12:46:19 pmHave you tried the PASSIVE_POWER_CTRL option (in config.h)?

author: indman
author_rank: Super Contributor
timestamp: July 15, 2025, 02:42:03 pm
content: Quote from: littlebalup on July 15, 2025, 12:46:19 pmYou can safely remove the STC chip, it is not needed for the work of the m-firmware and only interferes.https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg5332607/#msg5332607

author: littlebalup
author_rank: Newbie
timestamp: July 15, 2025, 07:14:38 pm
content: Quote from: madires on July 15, 2025, 02:04:48 pmYes I tried both with and without. I probably messed up some pin assignments. I'll investigate.Quote from: indman on July 15, 2025, 01:08:35 pmYour 1.51m works but constantly in probing loop. Your provided config files will be helpfull anyway. Thank you.Quote from: indman on July 15, 2025, 02:42:03 pmOk so I'll remove it. I tested the 2hry's compiled firmwarehttps://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg5332478/#msg5332478It seems to work fine. But is 1.51m. Any advantage to update to 1.55m?

author: indman
author_rank: Super Contributor
timestamp: July 16, 2025, 08:26:37 am
content: Quote from: littlebalup on July 15, 2025, 07:14:38 pmRead the m-firmware manual carefully frommadiresand then you will have less unnecessary questions!The tester can work in continuous (cyclic) and manual start modes.

author: littlebalup
author_rank: Newbie
timestamp: July 16, 2025, 12:59:39 pm
content: Quote from: indman on July 16, 2025, 08:26:37 amYep. Sorry for the dumb questions that you probably answered a million time. The project is really dense and a bit intimidating but I will deep dive into it.I already figured the feature with #define CYCLE_MAX.The 1.55m seems to run ok now with the proper power control configuration...I also figured out the memory space is very tight and fine tuning is necessary.Anyway thank you both for your help and your amazing work.

author: Proxy64
author_rank: Regular Contributor
timestamp: July 16, 2025, 01:53:22 pm
content: Hi guys,My LCR-TC1 has an LCD type Z180SN009 and a chip 324pa.-GND-VCC-RES PB4-A0 PB5-SDA PB6-SCK PB7I saw several similar boards in this topic, but I can't find this screen in the config_644.h file!Is it supported by Markus firmware?

author: madires
author_rank: Super Contributor
timestamp: July 16, 2025, 04:00:59 pm
content: A quick search returns that it should be an ST7735 which is supported.

author: Proxy64
author_rank: Regular Contributor
timestamp: July 17, 2025, 04:20:13 am
content: Quote from: madires on July 16, 2025, 04:00:59 pmExactly, but firmware 1.55m it missing in config_644.h, finally found at the bottom of this topic, just had to change the offset X&Y to 0.Code:/** Z180SN009 (ST7735)* - 4 wire SPI interface using hardware SPI*///#if 0#define LCD_ST7735 /* display controller ST7735 */#define LCD_GRAPHIC /* graphic display */#define LCD_COLOR /* color display */#define LCD_SPI /* SPI interface *//* control and data lines */#define LCD_PORT PORTB /* port data register */#define LCD_DDR DDRB /* port data direction register */#define LCD_RES PB4 /* port pin used for /RESX (optional) *///#define LCD_CS PB4 /* port pin used for /CSX (optional) */#define LCD_DC PB5 /* port pin used for D/CX */#define LCD_SCL PB7 /* port pin used for SCL */#define LCD_SDA PB6 /* port pin used for SDA *//* display settings */#define LCD_DOTS_X 128 /* number of horizontal dots */#define LCD_DOTS_Y 160 /* number of vertical dots */#define LCD_OFFSET_X 0 /* enable x offset of 2 or 4 dots */#define LCD_OFFSET_Y 0 /* enable y offset of 1 or 2 dots */#define LCD_FLIP_X /* enable horizontal flip *///#define LCD_FLIP_Y /* enable vertical flip */#define LCD_ROTATE /* switch X and Y (rotate by 90�) *///#define LCD_BGR /* reverse red and blue color channels *///#define LCD_LATE_ON /* turn on LCD after clearing it *//* font and symbols: horizontally aligned & flipped *///#define FONT_10X16_HF /* 10x16 font *///#define FONT_10X16_ISO8859_2_HF /* 10x16 Central European font *///#define FONT_8X16_WIN1251_HF /* 8x16 cyrillic font */#define FONT_8X16ALT_WIN1251_HF /* 8x16 alternative cyrillic font *///#define SYMBOLS_30X32_HF /* 30x32 symbols */#define SYMBOLS_32X32_HF /* 32x32 symbols, horizontally aligned & flipped *//* SPI bus */#define SPI_BITBANG /* bit-bang SPI */#define SPI_PORT LCD_PORT /* SPI port data register */#define SPI_DDR LCD_DDR /* SPI port data direction register */#define SPI_SCK LCD_SCL /* port pin used for SCK */#define SPI_MOSI LCD_SDA /* port pin used for MOSI *///#define SPI_HARDWARE /* hardware SPI *///#endif

author: Proxy64
author_rank: Regular Contributor
timestamp: July 17, 2025, 07:13:48 am
content: I'm still having a problem with my TC1 amtel324pa LCD display Z180SN009 with firmware 1.55m.If I enable the zener test (#define HW_ZENER), I only get a flashing white screen !Config.hCode:#define HW_ZENER#define ZENER_DIVIDER_CUSTOM#define ZENER_R1 100000#define ZENER_R2 12000#define ZENER_UNSWITCHEDConfig_644.hCode:#define TP_ZENER PA4note:I just noticed that I have the same result if I enable #define HW_ADJUST_CAP

author: madires
author_rank: Super Contributor
timestamp: July 17, 2025, 08:13:09 am
content: Have you set the pins as listed in the Clones file (TC-1, old variants)?Code:Pinout for test probes:#define TP_ZENER PA4 /* test pin with 10:1 voltage divider */#define TP_REF PA3 /* test pin with 2.5V reference */#define TP_BAT PA5 /* test pin with 4:1 voltage divider */#define TP_CAP PA7 /* test pin for self-adjustment cap */Pinout for fixed cap for self-adjustment:#define ADJUST_PORT PORTC /* port data register */#define ADJUST_DDR DDRC /* port data direction register */#define ADJUST_RH PC6 /* Rh (470k) for fixed cap */

author: Proxy64
author_rank: Regular Contributor
timestamp: July 17, 2025, 08:18:09 am
content: Quote from: madires on July 17, 2025, 08:13:09 amYes I did

author: madires
author_rank: Super Contributor
timestamp: July 17, 2025, 08:34:42 am
content: That kind of errror is new to me. Firmware too large (>32kB)? Besides that I have no other ideas.

author: Proxy64
author_rank: Regular Contributor
timestamp: July 17, 2025, 09:45:38 am
content: Quote from: madires on July 17, 2025, 08:34:42 amHumm//#define HW_ZENERCode:AVR Memory Usage----------------Device: atmega324pProgram: 32828 bytes (100.2% Full)(.text + .data + .bootloader)#define HW_ZENERCode:AVR Memory Usage----------------Device: atmega324pProgram: 32990 bytes (100.7% Full)(.text + .data + .bootloader)edit:Disabled some useless stuff like squarewave generatorAnd now it's working with zener test enable@madires THANK YOU!Code:Program: 29336 bytes (89.5% Full)(.text + .data + .bootloader)