hybridfree/eevblog-posts huggingface dataset:
Dallas DS1225Y - Is it possible to access Battery + from topside?   - Page 1
Forum section: electronics / repair

author: davefr
author_rank: Contributor
timestamp: June 17, 2023, 01:36:40 pm
content: I have a Tek scope with this 30+ year old NVRAM that still works. I've seen threads about adding a supplemental battery in parallel wiring from the underside. Has anyone done it from the topside without removing the IC from the board. Is it possible and any suggestions on technique?

author: wraper
author_rank: Unknown
timestamp: June 17, 2023, 01:49:02 pm
content: It's only possible with DS1225AB +70 as it's different internally from the rest. But doing so without removal it's not something you should do. Not to say you need to make a backup first if its contents are important.

author: DavidAlfa
author_rank: Super Contributor
timestamp: June 17, 2023, 04:49:48 pm
content: Nope, I've personally seen one of these under x-rays, the RAM covers the entire chip and the little coin battery is under it.Then I found:https://www.eevblog.com/forum/testgear/tek-2465b-dallas-nvram-replacement/?action=dlattach;attach=1105842

author: tkamiya
author_rank: Super Contributor
timestamp: June 18, 2023, 07:34:43 pm
content: Not on TEK scope, but I've done something like that for a Sun Microsystem Enterprise 3500 server. It's in storage (in physical sense) so I can't show you a picture. I recall filing carefully, attaching battery with wire, and making the final cut. If you do it right, you can keep the content.
Dallas DS1644 Time/NVRAM battery mod on TDS340/360? - Page 1
Forum section: electronics / repair

author: ChuckDarwin
author_rank: Regular Contributor
timestamp: July 12, 2021, 06:53:11 pm
content: I am working through my "someday" shelf and am up to a TDS340A. No notes to say what is wrong, passes diags, checkout procedures success, cal is still in RAM, seems to be OK. Candidate to be upgraded to a TDS360. Done.But now the ageing DS1644 VRAM... Option 1: desolder, read-out, battery mod or new 3rd party 1644 replacement, program, install in socket. From readings there seems to be mixed success in preserving the data even with good processes. Option 2 (leaning towards this approach): Protect area, excavate in-place for battery terminal leads and battery itself, tie in new battery source and disconnect old battery without grinding away something important. I can find the battery on the right of the module but have no idea where the terminal leads are in specific which would be helpful. Especially if I can tap and cut without major excavation. The upper side of the DS1644 module is blocked by the option 14 IDC connector for extra fun.I can find battery lead location information for other Dallas modules, but I can't find one for the DS1644. Anyone have this info? Better approach?

author: Labrat101
author_rank: Unknown
timestamp: July 12, 2021, 08:22:32 pm
content: to find the battery just run a small magnet over the top .the battery sits to the right side as of the picture . the top plastic shell is really thick . justdrimmel right side starting at the middle and follow the contour of the battery . the top lead of the battery is easy to remove but the bottom lead faces to the front right slightly up and is easilybroken and the connecting wire is stainless steel the battery lifts up if warmed slightly the bottomconnection can be cut with a small sharp modelling knife. to solder to stainless steel use organicflux & high tin content solder . I have done about a dozen of these replacements so far so good.which ever way you go you will lose the cal . but Recal is easy on this scope and the upgrade.I wrote a whole thing on this last year upgrading 340 to 360 & cal .saving the data will be harder than re cal which take about an hour apxthe red dot is about the centre of the battery . when the battery is really badthere is a slight bulginghttps://www.eevblog.com/forum/repair/upgraded-tds340-to-tds360-200mhz-1gsas-for-any-one-interested/msg3427528/#msg3427528about half way down the page i put a photo of the battery removedI hope this helps
Dallas DS1650Y & GQ-4X write problem - Page 1
Forum section: electronics / repair

author: MetalHead
author_rank: Contributor
timestamp: February 17, 2023, 03:57:05 pm
content: Hi guys!I try to move content from old DALLAS DS1650Y chip to the new one for my Tektronix TDS520A scope andI can't do this with GQ-4X programmer. DS1650Y is in a list of supported devices.Reading operation went fine, but when try to to write buffer into nvram chip it fails with thiserror message.Does anybody know what I'm doing wrong. Maybe chip is somehow write protected? I tried different speeds no way... (
DALLAS DS1743W replacement... - Page 1
Forum section: electronics / repair

author: whatboy
author_rank: Regular Contributor
timestamp: January 17, 2022, 06:42:54 pm
content: If this was already sicussed, sorry, I have not seen it!I got two SATO thermal transfer printers, I want to set'em up for selling, and notice this, both are SATO M-84Pro same printer difrent NVRAM, one has a dallas chip and the other has an EEPROM, guess it might be the same for the oscilloscopes!!! right???

author: Per Hansson
author_rank: Unknown
timestamp: January 17, 2022, 07:16:26 pm
content: Only the Dallas chip has a built in real time clock (RTC).So if that is not used then yes a regular SRAM can be an option.But then it is extremely strange why they would not just have used that for all units from the beginning.Because the Dallas chip is allot more expensive...Late edit: the other chip is not a SRAM but EEPROM and they require a very different process to write to.This is probably a very niche application that allowed one to substitute the other...
Damaged digital V/A meter  - Page 1
Forum section: electronics / repair

author: lordvader88
author_rank: Frequent Contributor
timestamp: June 25, 2019, 12:20:49 am
content: I have an ebay 100V 10A meter, and I've damaged it from not using it right, like mixing up wires more than once over a year so I don't remember..https://www.ebay.com/itm/DC-100V-10A-Voltmeter-Ammeter-Blue-Red-LED-Dual-Digital-Volt-Amp-Meter-Gauge-/312118220700The voltage works fine, but the current reading reading is not linear anymore. Spec's areQuoteIt used to be off a bit, but now its like it's off a few at 10's of mA and by 0.120A actual it reads 0.20A, 0.42A reads as 0.68AReminds me sort of like when I burned out a resistor in the divider chain of a DMM. I have the tools and even a digital microscope.How do these work ? Anyone know where to find a schematic ? I think they use a pretty generic chip for the V/A section.

author: james_s
author_rank: Super Contributor
timestamp: June 25, 2019, 12:26:22 am
content: Did you connect the current shunt across a voltage source? It sounds like you may have damaged the shunt resistor, that will cause the current reading to be wrong.Generally these things are just a microcontroller or ASIC with two voltage inputs, one of which reads the voltage across a current shunt.

author: lordvader88
author_rank: Frequent Contributor
timestamp: June 25, 2019, 12:51:50 am
content: The 1st time I used it I never read the diagram and probably did wire the shunt across the DUT.There's 2 ways to wire this. 1 is for a 30-100V, and the meter is pwer'd by another source under 20V. The other way is for 0-30VDUT and u can pwr the meter from the same source. And the shunt is wired different each time.I mixed that up too.Just today tho it's way off. I'm sure it was't like this last week.I can't see any letters/#'s on the chip, it's a fine pitch 20pin thing . It runs the LCD too. It uses an LM358 but most of it's pins are going to via's.These thing are a pain to take fully apart without melting stuff, and plus all the pins on the LCD would have to be de-soldered, dohIDK if it's the resistors I can see that are vital or if it's internal stuff in that chip that would be damaged.Nothing looks damaged.

author: lordvader88
author_rank: Frequent Contributor
timestamp: June 25, 2019, 02:21:42 am
content: I kid u not, if I turn the meter on it's side, with no load, it's going from 0.03-0.09A, just moving it around. It's shunt wires on the PCB of the PSU are in the middle of nowhere, so can't be touching anything wrong. How can the reading be changing from me moving the meter? Unless it's 60Hz AC noise in my room affecting it,seems the shunt connector is loose, moving it seems to have stopped the reading I just had moving it around.It's zero'ed again, but 0.57A reads as 0.78A
Damaged laptop LCD panel - what may have happened? - Page 1
Forum section: electronics / repair

author: Koray
author_rank: Regular Contributor
timestamp: September 14, 2022, 11:42:45 am
content: Hi there,I received a Thinkpad T450s laptop with a non-working display. I tested the mainboard with a known good display/cable combo, no problem there. Then I tested the LCD unit with a known good data cable, it works, too. So I decided that it was the cable that was faulty, and ordered a new one from Aliexpress. The new cable looked good, I connected it, and the laptop worked fine. I put a new OS on the machine, updated it and turned it off. The same evening I removed it from my bag, turned it on, and nope, backlight comes on and no image on LCD. Tested again with known good cable, no image. Tested the aliexpress cable on another screen, it works, cable looks OK.I then tested the new Aliexpress cable and found out that the metalized cloth tape that grounds connectors to each other is not complete, so the ground planes on the LCD was not properly connected to the ground on the mainboard and the shielding around the cable was missing for 2cm towards the end of the motherboard connector.Now the LCD will not work at all, backlight comes on, the fuses are OK, there are various voltages on the LCD board, but the LCD is always dark. It is a pity since the unit is a very high quality copy.Could this damage be a result of ESD damage? Maybe evil sparks during removal from the nylon cloth laptop bag? Is there any chance or way to revive the unit? Some photos attached (have no idea if they would help or not).Thanks in advance!Koray

author: m k
author_rank: Super Contributor
timestamp: September 19, 2022, 12:04:00 pm
content: It can also be either LCD or motherboard connector.When you connect it, it will work for a moment.

author: Koray
author_rank: Regular Contributor
timestamp: September 22, 2022, 06:57:10 pm
content: Thanks for the reply. Motherboard works OK with another LCD, but I will definitely check the LCD-side connector.K.
Damaged T4 transistor tester? - Page 1
Forum section: electronics / repair

author: orbanp
author_rank: Regular Contributor
timestamp: December 12, 2024, 04:18:45 pm
content: Hello Everyone,I have a T4 transistor tester (the yellow PCB, with green graphics display, from eBay) that gives a reading without any parts in showing that there is a 43pF cap between 2 and 3.I wonder if the tester is damaged? I do not recall the tester being zapped, though it could have happened without me noticing it.I cleaned the board with IPA, and before the cleaning the 43pF cap reading was between 1 and 3, and if the ZIF socket was closed the reading was between 2 and 3. Very interesting!I also did partially disassemble the ZIF socket, could not find any dirt or foreign matter inside the socket.The no part reading on the tester is obviously erroneous. If there is no part, it used to say that there is no part inserted or an unknown part is there.Other than this, the tester seems to measure parts normally.Measuring DC voltages on the inputs 1 and 2 reads about 18mV, 3 reads 1mV.I do have another T4 tester, yellow, etc, a bit younger, with different firmware, and it reads about 6mV on all inputs with no part.Measuring a couple of BJT transistors the beta readings differ between the to testers by about 15% - 20%.I might replace that Atmel 328P processor on the board, though removing that SM chip does not look too much fun.In that case at least I could compile the software myself.Any comment on the above?Thanks, Peter

author: u666sa
author_rank: Frequent Contributor
timestamp: December 12, 2024, 05:59:24 pm
content: Remove ATmega328 and stick it into programmer (I used T48), reflash the firmware and try it. If not, buy a brand new MCU.I bought mine here, it says page does not exists for me at the moment, but it might be accessible to you -https://aliexpress.com/item/1608634088.htmlMCU is real. When buying on ali, make sure you getting the real deal, not fake chip.

author: orbanp
author_rank: Regular Contributor
timestamp: February 15, 2025, 08:54:48 pm
content: Hello Everyone,All is well, the tester works fine with the original processor!It just needed running a "self test/calibration".I was reading the Transistor Tester engineering document to see what options I would want and what features the clone hardware supports when re-flashing the new processor, and was coming through the "Self Test" option.Luckily the Chinese clone tester has the self test option in the firmware.Running through a self test the process cleared up the error.The calibration values are stored in the EEPROM of the processor, and how and why it got changed or damaged is not clear. I will keep an eye on this.Peter
damaged usb 3 controller - Page 1
Forum section: electronics / repair

author: pitfermi
author_rank: Contributor
timestamp: September 15, 2020, 10:31:26 pm
content: i have an Asrock Z97 extreme 3 motherboard. I accidentally shorted vcc and gnd on one of the rear usb 3 ports (4 in total) when working with a usb-ttl adapter.since then, the max read/write speed has dropped to around 144MB/s. I tested with various usb 3 devices and disks, i can confirm that they are fine. the 2x front usb 3 ports work at full speed, as they apparently have a separate usb controller since they connect to the motherboard with a usb 3 header. all usb ports work fine, but apart from the reduced speed, i get some random reconnects/disconnects on some devices. im sure something is damaged in there.what is the procedure/steps to repairing a usb controller? I emailed asrock couple weeks ago but they never responded. any ideas?

author: pitfermi
author_rank: Contributor
timestamp: September 15, 2020, 11:17:32 pm
content: by the way, i have tried several drivers and check for hardware changes, disabling/uninstalling the controller on windows, no luck. thus i assume the problem is physical.

author: Haenk
author_rank: Super Contributor
timestamp: September 16, 2020, 05:44:19 am
content: Use a PCIe-card as a replacement.

author: magic
author_rank: Super Contributor
timestamp: September 16, 2020, 10:37:00 am
content: The controller is probably built into the chipset. But it doesn't care about VCC short to ground. Either you shorted something else or maybe it's a problem with the power supply on this port. Is it still 5V as it's supposed to be?

author: pitfermi
author_rank: Contributor
timestamp: September 17, 2020, 12:09:09 am
content: all 4 ports have the same problem. power is still 5VQuote from: magic on September 16, 2020, 10:37:00 amI'd rather try to repair it myself than spend money on additional hardware. there are already 4 ports on the rear of the motherboard.Quote from: Haenk on September 16, 2020, 05:44:19 am

author: magic
author_rank: Super Contributor
timestamp: September 17, 2020, 05:13:47 am
content: Quote from: pitfermi on September 17, 2020, 12:09:09 am5V also under load?In general, you are probably screwed. AFAIK there isn't much in there - polyfuses on the 5V line, maybe some ESD diodes on the signal lines and the lines go to a chip. The chip is likely difficult to replace (or even buy) and it might be the southbridge for all we know. Check in device manager what controller it is.

author: pitfermi
author_rank: Contributor
timestamp: September 24, 2020, 06:56:58 pm
content: so, it seemed to be a software issue. reinstalled windows, problem fixed. not sure what happened there
Damn component - Page 1
Forum section: electronics / repair

author: courantelectro
author_rank: Contributor
timestamp: August 27, 2021, 07:52:18 pm
content: Hello,do you know this damn component? Manufacturer, Part number?Thank you

author: fzabkar
author_rank: Super Contributor
timestamp: August 27, 2021, 08:27:12 pm
content: http://www.smdmark.com/en-US/search/code?id=b2
DANA 4200 Schematic - Page 1
Forum section: electronics / repair

author: Squarewave
author_rank: Frequent Contributor
timestamp: May 13, 2019, 07:12:10 pm
content: Hello, does anyone have a schematic for one of these please?I think the TX is open on the primary on mine, so I want to confirm the rest of the meter is ok by hooking up some lab power supplied where the secondary would sit.Thanks in advance.

author: picburner
author_rank: Frequent Contributor
timestamp: May 14, 2019, 08:33:20 am
content: You can find a well made copy of the manual (user/service with schematics) at Artek Manuals for a modest amount.It cannot be found for free on the net, at least I haven't found it anywhere.

author: Squarewave
author_rank: Frequent Contributor
timestamp: May 14, 2019, 04:11:46 pm
content: Thanks. Unfortunately the prices on the website make this uneconomical to repair.
DANA 5800 Digital Multimeter/Ratiometer seeking info/ Repair Thread  - Page 1
Forum section: electronics / repair

author: valley001
author_rank: Frequent Contributor
timestamp: December 20, 2019, 08:33:09 pm
content: Hello all,Edit: Ill also use this as a trouble shooting thread.I am seeking any additional information on this model. I do have a copy of the manual but is not comprehensive, it does not contain the usual troubleshooting information that DANA seems to have provided in their manuals. It does at least contain schematics. There is practically nothing out there on the web on this unit, I have hope that someone with boxes upon boxes of test equipment manuals may have some additional information on it, like a separate service/repair manual.My example has issues with the digitizing/logic sections, I think.
Dana Exact 7271 / Search for Manuals (Operating + Service) - Page 1
Forum section: electronics / repair

author: olliisit
author_rank: Newbie
timestamp: September 20, 2020, 03:36:45 pm
content: Hi there ,I get my hands on the Dana Exact 7271 Sweep Generator.It has Mechanical + Electrical damages (Burnt Resistors)So - I search for Manuals (Operating + Service).The Circuit/Manual Websites I checked - dit not have It.Any suggestions where to get the Manuals ?Thkns in Advance

author: KMoffett
author_rank: Regular Contributor
timestamp: September 20, 2020, 04:44:41 pm
content: https://www.ebay.com/itm/Dana-Exact-Model-7271-Manual-Lin-Log-Sweep-Generator-/124302500597
Danfoss (SMA) flx pro solar inverter error 361 - Page 1
Forum section: electronics / repair

author: monchichack
author_rank: Newbie
timestamp: May 08, 2021, 08:32:11 am
content: Hi,A number of inverters on site are failing due to error 361 which suggests either output protection relay or relay drive transistors maybe at fault.Upon opening an inverter I've noticed a failed smt cap on the output driver section.Has anyone got any experience with these devices? Once repair is completed, is there a software reset procedure?Thanks

author: Mohamad
author_rank: Newbie
timestamp: January 13, 2024, 12:15:50 pm
content: Hi I have same problem on my site and a number of inverters are failing due to error 361.Were you able to solve the problem?
Dangers in opening a 240V vinyl turntable? - Page 1
Forum section: electronics / repair

author: bleak
author_rank: Newbie
timestamp: January 16, 2020, 02:42:00 am
content: Hi all, first postJust wondering if there's any particular things I should watch out for when opening a direct drive turntable for repair?I have a 240v Gemini SA 600 turntable that I am thinking of opening as it is not rotating but otherwise seems to be operational. Of course it has all the standard, scary-sounding warnings on its case.Note: I am very very novice with electronics.Thanks o/

author: james_s
author_rank: Super Contributor
timestamp: January 16, 2020, 04:32:18 am
content: As long as you unplug it first there is not really any risk to yourself. There could be a risk to the turntable if you do not know what you're doing though. In most cases there is no visual indication of a fault.

author: shakalnokturn
author_rank: Super Contributor
timestamp: January 16, 2020, 08:58:39 am
content: I've repaired a few of those atrocities in the past, usually the motor driver IIRC.The only direct drives I've seen used by DJ's that were of decent design were Technics, all the others are a waste of money IMHO.Edit: First check platter bearings /grease haven't stiffened.

author: tggzzz
author_rank: Super Contributor
timestamp: January 16, 2020, 09:23:20 am
content: Quote from: bleak on January 16, 2020, 02:42:00 amMake sure there is no chance of mechanically damaging the tone arm.

author: andy3055
author_rank: Super Contributor
timestamp: January 16, 2020, 05:54:34 pm
content: For good measure, remove the head shell with the cartridge and the stylus before you start on it. Those are the most delicate in the whole unit. Removing the shell is just too easy to even write about!

author: james_s
author_rank: Super Contributor
timestamp: January 17, 2020, 07:07:34 pm
content: It is on some, but many turntables do not have a removable headshell. I just remove the stylus when I work on mine.

author: JohnG
author_rank: Frequent Contributor
timestamp: January 17, 2020, 07:46:41 pm
content: The most serious danger is that you will amass a giant collection of vinyl and that this could fall over and maim or injure someone.Cheers,John
Danica Modular power supply TPS3052A manual/schematic - Page 1
Forum section: electronics / repair

author: wedgetail
author_rank: Contributor
timestamp: September 14, 2019, 04:22:49 am
content: I have been cleaning up in the den and found this unit, I have forgotten how it came to land up with me and in what state. Visually it looks fine. Spent a lot of time on the searching the internet to find out more than just a part spec sheet.So far I gather it 5V and +/- 12V and several amps. Initially is there any one who can provide some more information. The quality of the unity had me thinking this would be easy to find some information on the internet, this is the second time I am attempting to pin it down and without luck after several hours hunting around. My guess so far originating in europe.Will take a photos later and post.

author: wedgetail
author_rank: Contributor
timestamp: September 18, 2019, 03:02:08 am
content: Finally got the photos

author: wedgetail
author_rank: Contributor
timestamp: October 19, 2019, 05:14:50 am
content: I will add another item here, just in case somebody have schematic information.Ultra 60 TelBix power supply for LEDs looks like the following picture, it is dead with no sign of damage.If I can get hold of a schematic I will try and repair.
Data I/O 3980 Power Supply Change->Callibration Error  - Page 1
Forum section: electronics / repair

author: Teichhermelin
author_rank: Regular Contributor
timestamp: March 20, 2021, 01:04:13 pm
content: The old power supply could no longer be saved. Now I've installed a new one. But the calibration step brings an error. Now I don't dare to adjust the regulator on the power supply. I measure 9.64V at pin78 and 1 and 11.88V at pin 1 and pin 24. It should be smooth 10V and 15V. Now my question in the round ... should I just turn up the 12 volts until it fits?

author: picburner
author_rank: Frequent Contributor
timestamp: March 20, 2021, 04:51:28 pm
content: 12V?to me the 2900/3900/3980 power supply turns out to be 15VDC.

author: Teichhermelin
author_rank: Regular Contributor
timestamp: March 20, 2021, 06:48:29 pm
content: So I will probably have to readjust something on the potentiometer. The power supply is the original MAP80-1012G that was built into me.

author: Teichhermelin
author_rank: Regular Contributor
timestamp: March 21, 2021, 08:59:44 am
content: So I turned up the no-load voltage on the power supply to 15.15V. Then exactly 15.00 V reference voltage is applied. Now the device is running again!

author: picburner
author_rank: Frequent Contributor
timestamp: March 21, 2021, 09:21:18 am
content: All solved then.Also in thedataioEPROM groupthey confirm that the power supply must be 15VDC (post#4300 point 4), then you can find the software version 9.40 there.
Data I/O model 201 Eprom Programmer. - Page 1
Forum section: electronics / repair

author: Paceguy
author_rank: Regular Contributor
timestamp: February 13, 2022, 03:11:08 pm
content: I recently purchased a Data I/O MODEL 210 Eprom programmer. Sadly 7 of the 16 keypad keys were broken off when it arrived. Does anyone know who make those tactile switches they used and would anyone happen to have a keypad from a parted out unit?
Data needed on Ledex Rotary Solenoid - Page 1
Forum section: electronics / repair

author: Roman oh
author_rank: Regular Contributor
timestamp: February 11, 2025, 12:06:10 am
content: I am repairing a piece of older machinery and need data on a Ledex Rotary Solenoid Model A37-509-001. This is quite an old unit.All my usual googles and a heavy rummage through all the data stored in my shed, have turned up nothing.Can anyone help?Thanks in anticipation….Roman

author: Poroit
author_rank: Frequent Contributor
timestamp: February 11, 2025, 04:28:11 am
content: G'day Roman,Unfortunately nothing in my data bank.What are you actuating with this Solenoid?If you know the torgue required to turn it,maybe you can select a newer model of Ledex.

author: Roman oh
author_rank: Regular Contributor
timestamp: February 11, 2025, 10:31:32 am
content: Thanks, Poroit,I have indeed identified what looks like an equivalent from the current Ledex range, but there are people in my organization who are hung up on paper trails rather than common sense ..Roman
Data Precision 8200 - 100V range out of pot range during adjustment - Page 1
Forum section: electronics / repair

author: Rax
author_rank: Super Contributor
timestamp: October 16, 2023, 02:17:32 pm
content: Hi all,I am adjusting a DP8200 and everything is going alright, except the 100V range is not adjusting enough to get into calibration. I am barely at 69.9038V and I've spun the pot to much I am certain I'll run out of range before I get it within 100uV of 70V as it's supposed to be.I enclose the schematic of the corresponding circuitry.Any input and thoughts welcome.

author: Kleinstein
author_rank: Super Contributor
timestamp: October 16, 2023, 02:47:17 pm
content: There are relay contacts in series with the 10 K +90 K (incl. trimmer) gain setting resistors. Especially K2 in series to the 10 K may be an issue with relay contacts that were not used for a long time. A few cycles and whatching the change may be a good idea.

author: Rax
author_rank: Super Contributor
timestamp: October 16, 2023, 09:04:28 pm
content: My other thing to investigate is whether the 130V rails are in good shape. It's been a while since I last looked at this, but I think the Q3-Q7 is the stage doing the 10x and if the rails are too low maybe that robs the stage of enough headroom to go as high as it needs to.

author: RandallMcRee
author_rank: Frequent Contributor
timestamp: October 16, 2023, 10:08:23 pm
content: Quote from: Rax on October 16, 2023, 09:04:28 pmYour description makes it sound like that trim pot is busted. Easily happens. Why don't you confirm that hunch, first?The pot can only trim a small amount, though, so perhaps look at your working unit to confirm correct voltages around the trimmer and its associated resistor.

author: doktor pyta
author_rank: Frequent Contributor
timestamp: October 17, 2023, 06:00:50 am
content: Dirty relay contacts are common issue of DP8200.Fortunately they are easy to open an clean with paper soaked with IPA.

author: Testtech
author_rank: Regular Contributor
timestamp: October 18, 2023, 09:18:54 pm
content: There is a 68K resistor, R51, near the rear of the board that often burns up or changes value. Also the hv amp power transistors and their drivers can fail.
Data Sheet Needed - Vectron 224-8037, 100 MHz OCXO - Page 1
Forum section: electronics / repair

author: rubidium
author_rank: Regular Contributor
timestamp: October 04, 2020, 03:22:15 pm
content: Anyone have a data sheet for this OCXO? The issue is that the internal 10-turn frequency adjust pot has a glitch right at the 100 MHz "sweet spot."So in my attempt to calibrate it against a frequency standard I end up with instability at the 100's of mHz to 1 Hz level. I'd like to replace the pot, but the unit is sealed with solder and I hate to embark on that risky adventure. In addition to the SMA RF output port, there's a 7-pin terminal arrat at the base of the unit. I was hoping that the OCXO can accommodate an external frequency control voltage and thereby bypass the corrupted pot. But I can't find a data sheet anywhere to know how those pins are assigned.Jim

author: eblc1388
author_rank: Frequent Contributor
timestamp: October 06, 2020, 05:53:05 am
content: Searching for vectron OCXOs led me to the following OCXO pinout diagram of a similar Vectron Model. I would say it has a high possibility of having the same pinout as your existing unit. It shows the respective pin arrangement and function.First you can measure if there is a DC voltage at pin #7 of the OCXO, if so, you can connect a 10K~20K POT between pin#3 and Pin#7, with the wiper going to pin#6. Hope this helps.

author: rubidium
author_rank: Regular Contributor
timestamp: October 07, 2020, 09:08:20 pm
content: There appears to be a lot of variability with pin assignments on similar looking Vectron OCXOs - at least with these older, now obsolete, units. Mine came in a Wavecrest DTS-2070 time interval system, and is being driven by 24VDC to pin 4, with the ground return to pin 3 which is also connected to the case. That agrees with your diagram. But I have explored the other pins, and discovered that pins 2 and 7 are also connected to the case. The remaining pins 1, 5, and 6 have no continuity to anything. I was hoping that these other pins would support external electronic frequency control. The problem is that the internal frequency control 10-turn potentiometer smoothly controls the frequency over a +/-500Hz range - except in the +/-1Hz subrange centered right at 100MHz, where there is a bad glitch. Must be a worn spot caused by 20+ years of people making cal adjustments. So frustrating, since this results in poor thermal and mechanical stability when I try and calibrate the thing myself against one of my house standards. The unit has been powered on for a week and is still drifting around. So I was hoping to bypass the internal pot with an external pot, but it appears that's not going to happen.Since my original post, I found a used 100MHz Vectron OCXO that was quite inexpensive (model 229-9268) for which I do have the pin map (from a 5-year old post on time-nuts), and so I'll try and adapt that once I receive it. If I end up failing at that, I'll just hook up my HP8664A sig gen, set it to 100 MHz and externally drive it with my 10MHz house standard.Jim
Datasheet 7 segment LED display KTL 1003 - Page 1
Forum section: electronics / repair

author: Rafiki
author_rank: Contributor
timestamp: July 20, 2025, 12:36:58 pm
content: I wanna replace the LED display of my refrigerator box as it's hardly readable anymore. Does anyone know where to find a datasheet of the current one? Think type is KTL 1003. See pictures.

author: ledtester
author_rank: Super Contributor
timestamp: July 20, 2025, 12:45:43 pm
content: The 1003 is likely a date code - either Oct of 2003 or March of 2010.A web search came up with this:Quotehttps://www.toyo-led.com/en/product/four-digits-displays/I would email Toyo to see if they can help you.It is also likely that you can use another LED display that has the same dimensions, pinout and common pin (either common cathode/anode).Here is a video which shows how to find a replacement for a LED display including determining the pinout and searching the Digikey catalog for a suitable match:Finding Replacement 7-Segment Displays -- Kainka Labshttps://youtu.be/qcLF-2hg0a4They demonstrate the procedure for a single digit but a lot of it carries over for 4-digit modules.

author: amyk
author_rank: Super Contributor
timestamp: July 20, 2025, 07:52:11 pm
content: https://www.toyo-led.com/wp-content/uploads/2017/02/E40362-LI.pdfLiterally the first result on Google for the part number.

author: ledtester
author_rank: Super Contributor
timestamp: July 20, 2025, 09:21:39 pm
content: Quote from: amyk on July 20, 2025, 07:52:11 pmUnfortunately that datasheet is for a 3 1/2-digit display. But the suffix is different so it still may be a Toyo part.

author: Rafiki
author_rank: Contributor
timestamp: July 21, 2025, 06:56:10 am
content: Thanks. Wonder why my search didn't find this. Of course I tried every combination also with E40362. Anyway datasheets at Toyo don't give an indication of brightness. Pinning is maybe like E40391-L3&I3.I hoped I can save the time to find out the correct pinning and brightness by myself. I asked Toyo via email. But honestly I don't expect any answer.

author: fzabkar
author_rank: Super Contributor
timestamp: July 24, 2025, 08:16:51 am
content: Quote from: ledtester on July 20, 2025, 09:21:39 pmIt's not Toyo.https://t1.daumcdn.net/cfile/tistory/2519504758BC6CC230KTL = Kindwin Opto Elektronic (H.K.) Co. Ltd.The part numbers match the number of digits in the photos in this thread.

author: amyk
author_rank: Super Contributor
timestamp: July 25, 2025, 02:12:24 am
content: How annoying, two different manufacturers with the same part number format and the same category of parts, but different parts.

author: Rafiki
author_rank: Contributor
timestamp: July 25, 2025, 12:08:54 pm
content: Thanks fzabkar.Although I can't find a specification of brightness I've enough info now to search for a replacement.
Looking for Datasheet for A2C44458 IC106 - Page 1
Forum section: electronics / repair

author: BC547B
author_rank: Contributor
timestamp: January 13, 2025, 06:46:53 pm
content: Hello, looking for the datasheet of this IC: A2C44458 IC106 found on a drivetrain control module of a Jeep Grand Cherokee. The internet lead me that it's manufactured by Texas Instruments. But couldn't find any info about it... Any information would be helpful. I've attached a pic.Thank you,

author: Harry_22
author_rank: Frequent Contributor
timestamp: January 13, 2025, 07:31:12 pm
content: Hi!I found only this info:A2C44458 is a QFN-56 package from Texas Instruments. It is a low-power, low-voltage, high-performance, 8-bit microcontroller with integrated Flash memory. It is designed for use in embedded applications such as automotive, industrial, and consumer applications. It features an enhanced 8051 core, up to 16KB of Flash memory, up to 4KB of RAM, up to 32 I/O pins, up to 4 UARTs, and up to 4 timers. It also features an integrated 8-channel 10-bit A/D converter, an integrated SPI, and an integrated I2C interface. It is suitable for applications requiring low power consumption, low cost, and high performance.

author: BC547B
author_rank: Contributor
timestamp: January 13, 2025, 07:42:54 pm
content: Very valuable info thank you so much!!

author: amyk
author_rank: Super Contributor
timestamp: January 14, 2025, 04:35:16 am
content: Quote from: BC547B on January 13, 2025, 07:42:54 pmSurely you're joking?Everywhere I've seen it for sale and looked at the pictures it's a QFN64. That post above looks more like an AI hallucination than anything which could be considered true.

author: ercan4434
author_rank: Contributor
timestamp: January 14, 2025, 03:53:28 pm
content: Someone asked this chip in china ti support but nothing found there too. Some websites says its a amplifier audio chip For ECU Board(that doesnt really make sense to me) and some says for ECU injection repair that doesnt really make sense to me. Its a specialized chip for sure but maybe if you post the photo of the pcb we can guess its purpose.
DATASHEET for ic SN76025 - Page 1
Forum section: electronics / repair

author: manoj2025
author_rank: Newbie
timestamp: August 01, 2025, 02:02:36 pm
content: I searched and could not find datasheet for ic SN76025 which is pwm motor driverused in hp d1668 printer.Can anybody give me the datasheet.

author: squadchannel
author_rank: Frequent Contributor
timestamp: August 01, 2025, 02:30:27 pm
content: https://e2e.ti.com/support/motor-drivers-group/motor-drivers/f/motor-drivers-forum/920442/ic-datasheet-sc76025Quote

author: manoj2025
author_rank: Newbie
timestamp: August 01, 2025, 03:04:35 pm
content: I saw that link but is datasheet available with anybody please post .

author: manoj2025
author_rank: Newbie
timestamp: August 01, 2025, 03:09:21 pm
content: any individual seller for this ic in india payment mode upi /cash on delivery please reply
Datasheet for L6252 - Page 1
Forum section: electronics / repair

author: Quarlo Klobrigney
author_rank: Super Contributor
timestamp: June 11, 2019, 11:52:18 am
content: Does anyone have a datasheet for an L6252, PLCC-44 package from ST?All the usual suspects on the web have been tried.The exact P/N is L6252 ES4.

author: Chris56000
author_rank: Frequent Contributor
timestamp: June 11, 2019, 07:13:59 pm
content: Hi!What's it used in?I found a datasheet for the 44 pin L6256 which is an H.D.D. motor drive controller.If it's any help you could trace round your L6252 and see if any of it's external components and connections match up with the L6256 – if your i.c. is from a h.d.d that's failed., then you might be able to get another h.d.d. with the same and swap 'em over!Chris Williams

author: Quarlo Klobrigney
author_rank: Super Contributor
timestamp: June 11, 2019, 09:58:40 pm
content: These are "loosies". No circuit board to reference to.

author: amyk
author_rank: Super Contributor
timestamp: June 12, 2019, 03:27:01 am
content: TheL6254is also a HDD IC, as is the L6250 and L6253 (http://www.shrubbery.net/~heas/willem/PDF/SGS-THOMSON/SGS/221.pdf-- where they are referred to as "3/5V Spindle Sensorless Driver" and "12V High Power Combo" -- no other references can be found on the Internet probably because these ICs are from the late 90s/early 00s...), so it's a pretty safe bet what the '52 is... but beyond "for HDD" nothing else can really be guessed.

author: Quarlo Klobrigney
author_rank: Super Contributor
timestamp: June 12, 2019, 10:50:59 am
content: I appreciate the try, but for example, an L297 & L298 are 2 different animals, if you are looking for similarities in number only. Yes they are motor related, but as far as connections it's anyone's guess.So I guess I am still looking for a datasheet......I've been continuing a parts inventory and just wanted to qualify them before sticking them back as unidentified.I can finally start to see a clear area of my workbench. A whole square 2 feet now!

author: CJay
author_rank: Super Contributor
timestamp: June 12, 2019, 11:49:17 am
content: Thought it rang a bell, they're used on Western Digital PATA HDDs,http://www.hdd-repair.com/gallery/hdd-photo-collection/western-digital-photos/186-western-digital-wdxxxxbb-00aua1-001003-pata.html

author: Quarlo Klobrigney
author_rank: Super Contributor
timestamp: June 12, 2019, 12:11:39 pm
content: I'm afraid that's an L6262 you've linked to:

author: CJay
author_rank: Super Contributor
timestamp: June 12, 2019, 08:48:27 pm
content: Ah, my bad, plus it's tqfp, not plcc but I think you'll find the 6252 on older WD drives

author: fzabkar
author_rank: Super Contributor
timestamp: June 13, 2019, 04:53:06 am
content: This chip was used in Western Digital's Caviar AC35100 and AC34000 models.See pages 10 and 11:https://www.acelab.ru/dep.pc/doc.pc3000dos/050530.001/PCA35100.pdf
Datasheet for NEC CP2001D VFD driver IC - Page 1
Forum section: electronics / repair

author: pcprogrammer
author_rank: Super Contributor
timestamp: March 25, 2024, 01:27:12 pm
content: I'm looking for the datasheet of a NEC IC with a data code of 1984. It has 38 pins and has narrow pin spacing compared to a standard dip IC. The width of the IC is the same as a standard 28 pin EPROM or 40 pin CPU.The manufacturer is NEC and the IC code is CP2001D.I found some suppliers with google, but could not find a datasheet in any of the usual places.The same applies for the display itself. Also NEC with the marking FIP40A5X. I did find it mentioned in several NEC product catalogs of 1988 - 1990, but no details on the pinout, voltages, etc.It is a would be nice to have thing to make reverse engineering easier, or bodge up some repair of the unit. The display is very old and I can't recall where I bought it and if I worked on it myself. Has been in a box for >30 years. The cut pins on the one CP2001D don't give the same measurement with a DMM as the same pins on the other CP2001D's on the board.I do have another one that works as intended. You can see ithere. The defective one misses some pixels in each character.

author: DavidAlfa
author_rank: Super Contributor
timestamp: March 25, 2024, 01:55:43 pm
content: Not the datasheet but a very useful schematic.Apparently each ic is made of four shift registers which can be daisy-chained.I guess it takes all the clocks and latches the data when OE is released.Source:https://ru-radio-electr.livejournal.com/1467417.html

author: pcprogrammer
author_rank: Super Contributor
timestamp: March 25, 2024, 02:52:37 pm
content: The VFD panel in that article looks to be the same as mine. Guess it was ripped from the second PCB in that article, the one with the CP2001's on it. My board is different but also has four of these CP2001's on it.I dove into my archive and found the manual of the display module with the max voltage and current specifications and how to control it from another device.With it a drawing I made of the boost converter that is on the module. Must have cut the pins myself back then.Also found the schematic for another VFD I have and was looking into connecting it up again. Saves a bit of work on that one.

author: pcprogrammer
author_rank: Super Contributor
timestamp: March 26, 2024, 09:46:58 am
content: Dug a bit deeper into my archive and found a bit more stuff on this module and the CP2001.The reference manual I found is for the FM40X1AA-A, where as my module is FM40X1AA-B. The interface with a host is the same though. The A module uses different drivers for the display.From what I have I can see that I played with it in 1994.Attached are zips containing the scans of what I have on this. There is a bit of my old handy work in there like shown with the attached images.Edit: I'm having some weird behavior trying to post with the .zip files attached. It does not save it and goes into a "start new topic" mode.Turns out the files are to big, and at the last try it told me so.

author: pcprogrammer
author_rank: Super Contributor
timestamp: March 26, 2024, 09:53:35 am
content: So here are the other files.
Datasheet for Nichicon SE series ? - Page 1
Forum section: electronics / repair

author: MathWizard
author_rank: Super Contributor
timestamp: May 02, 2024, 06:26:06 am
content: I'm checking some caps in an older stereo from the 1980's, and I can't find much info on Nichicon SE(M) series caps, they are typical looking radial leaded electrolytic's, only 85C rated.What's similar to them, what table or datsheets might I use to check their dissipation factor or ESR ?

author: fenugrec
author_rank: Frequent Contributor
timestamp: May 02, 2024, 05:03:55 pm
content: Might try on archive.org or bitsavers, sometimes you can find scans of old catalogs.Looking at the schematics where it's used will give a clue as to the important characteristics.

author: MathWizard
author_rank: Super Contributor
timestamp: May 02, 2024, 06:15:45 pm
content: So far their ESR seems pretty good, there's some Elna and Nippion caps as well, I can't find the exact Elna datasheet yet either. But Besides 1 or 2, they seem pretty good, for DF.But I don't check a lot of caps, so I don't have a good feel for the numbers.
datasheet needed  6802 40.000 MHz AT OCXO Crystal Oscillator 5VDC  - Page 1
Forum section: electronics / repair

author: Smile2016
author_rank: Regular Contributor
timestamp: September 23, 2024, 05:12:19 pm
content: datasheet needed 6802 40.000 MHz AT OCXO Crystal Oscillator 5VDC , e-bay product claims to be Vectron....
Datasheet needed  - Page 1
Forum section: electronics / repair

author: Alimash
author_rank: Newbie
timestamp: March 27, 2025, 08:20:42 pm
content: HelloI need the datasheet for the APC2010 IC.It's an ASIC as i found out and manufactured by ON semi, and it's used in an inverter I'm trying to repair.

author: loulou31
author_rank: Contributor
timestamp: March 27, 2025, 09:17:56 pm
content: Hi,If it is an ASIC that means it is Application Specific IC and the it is a customer specific device. Usually the manufacturer is not providing the specification nor the device as standard product. To have the specification you have to ask the customer.Regards.Jean-Louis

author: suntime
author_rank: Contributor
timestamp: March 27, 2025, 09:19:31 pm
content: Maybe this will help:https://b.itemimg.com/i/213237993.3.jpg?1

author: fzabkar
author_rank: Super Contributor
timestamp: March 28, 2025, 12:18:35 am
content: https://monitor.espec.ws/files/apc_back_ups_250i_400i_600i_sxems_837.pdfhttps://www.geocities.ws/saphanlex/ups/1.pdf

author: coromonadalix
author_rank: Super Contributor
timestamp: March 28, 2025, 03:19:40 pm
content: only place no datasheet who pop's up is :https://www.aliexpress.com/item/1005002304648987.htmlthey are not expensives ..
Datasheet or spec required for p87032 - Page 1
Forum section: electronics / repair

author: mOSkit
author_rank: Contributor
timestamp: October 11, 2025, 01:22:32 pm
content: HiI searched the entire internet and did not found any single reference to this following chip.On the case it's saying: 3-215, P87032 then below MTI9312.All I'm interested Is which is the output trigger pin and output characteristics.It's currently tied up into inductive pickup on a timing light.Thanks for any help

author: fzabkar
author_rank: Super Contributor
timestamp: October 11, 2025, 07:08:17 pm
content: It's a hybrid package, so it's probably a custom part. "9312" could be a YYWW date code, ie week 12 of 1993. Alternatively, 8703 could mean week 03 of 1987.Maybe it's a signal conditioning circuit for the pickup in your timing light.https://patentimages.storage.googleapis.com/fd/08/e5/7973deff9e670f/US4713617.pdfQuoteI have attached similar hybrids from a Sony MXP-3000 mixer and one other. It would appear that the bottom line is the date code or batch code, and MTI could be the manufacturer, possibly Japanese.
Date and time in HP 8596E - Page 1
Forum section: electronics / repair

author: hnjmkl
author_rank: Regular Contributor
timestamp: January 22, 2022, 07:00:32 am
content: I replaced supercap and battery to my 8596E, the new date and time entry is apparently not detected, I ask if yymmdd entered from the keyboard should appear at the same time in the dedicated area at the top left. Solved thanks.