hybridfree/eevblog-posts huggingface dataset:
ICHILL Geforce 980 TI Air Boss repair - Page 1
Forum section: electronics / repair

author: Sci666
author_rank: Newbie
timestamp: December 03, 2018, 01:47:31 pm
content: helloi got some average to good soldering skills but i dont have many experience with measuring graphics cards (but i got a realative good multimeter and a hot air station ... unfortunately no IR station until now ;-) )i had a ichill GTX 980 TI. the fans spins but no picture.no optical damage or burn marks on any parts. no part gets warm if its powered up and the GPU stays cold too !measuring input and output of some parts seems to be good ... all necessary inputs got 12V or 5 volts but it stops at the coils ... all of them 0 Volts output .... the middle ones beeps to ground in the beep modesee picture. do you need some more informations ?i dont really know how to go on to find the problem because i dont know the interaction between all these parts.can you give me a hint what i can measure next to identify the faulty part ?so questions,1)why is there no voltage on the GPU lines from the coils ?2)why is there no voltage to RAM from the 2 middle coils ?3) why is there a beep to ground - is there a short somewhere in tha ram circuit ?

author: Rasz
author_rank: Super Contributor
timestamp: December 03, 2018, 03:04:16 pm
content: probably junk bin candidate

author: wraper
author_rank: Unknown
timestamp: December 03, 2018, 03:15:36 pm
content: Quote from: Sci666 on December 03, 2018, 01:47:31 pmLow resistance likely is fine but not a complete short. "Beep" does not say anything about what it actually is.

author: Sci666
author_rank: Newbie
timestamp: December 10, 2018, 02:01:49 pm
content: ok ... but i dont understand why theres no voltage at the output side of the coils .... so the mosfets didnt let the voltage through ? because of ... what can happen here ... maybe the PWM signal is missing ? what happens if theres no PWM ? can i measure out the PWM signal here ?
Repair HP 3467A - Showing No Display - Page 1
Forum section: electronics / repair

author: VK5RC
author_rank: Unknown
timestamp: December 09, 2018, 10:47:44 am
content: As a bit of an old HP gear fan, and the small boy in me likes moving parts - I bought an "As Is" HP 3467A a 4 1/2 digit 4 channel recording DMM with Maths and Time stamping on the thermal paper printer.On arrival - it had not clearly been used for some time - it worked for a minute until a command to print was requested - the printer moved a little then the display (LED) vanished . On repeat switch on - nothing. Checking DC PSU voltages for values and ripple were OK, the microprocessor clock was active and but the micro appeared to be rebooting every few seconds or so.Manual Issues. An original manual took some months to find as the one on the Keysight website is borderline readable - I have scanned the Letter sized pages, but the schematics are beyond my scanning abilities - if you need a section let me know and I can send a copy and or photo.The manual indicates the micro can reboot if it isn't happy with power voltages etc. They appeared OK but it all went pear shaped at the time of using the printer - so I looked there first.Printer Unit Access- to get to the printer you need to unclip the front plastic face - this is achieved form the top of the unit by pushing down carefully. the 3 lugs (see photo below) and then the face hinges forward. The printer unit is held in by 4 screws on the side, 2 power cables and a large signal harness.This printer uses a small motor (metal cog in photo below) driving an intermediate cog (indicated below in photo) and this intermediate cog had perished and a large chunk had broken off, With quite a bit of care and luck I was able to make another from plastic stock I had, the completed unit below. Took me three goes to get it right mind you. (Mini lathe, rotary table and small mill) Cog 10.0mm diameter 30 teeth.Rewinding the printing head unit back to its 'returned' position and a bit of dry lubrication was applied. Replacing the unit initially resulted in the paper feed being a bit erratic, cleaning the 2 drive rollers with a bit of water then a very gentle sandpapering to get a bit of friction and all is working again!Results below

author: Floopy
author_rank: Regular Contributor
timestamp: December 09, 2018, 06:57:59 pm
content: Very nice,when I find physical manuals I always make sure that they have been scanned. Hp gear is always a pleasure to work with. At least the old gear. Easily servicable, clearly layed out.

author: VK5RC
author_rank: Unknown
timestamp: December 10, 2018, 12:12:37 am
content: Thanks, I enjoy these challenges - I know my limits

author: xrunner
author_rank: Super Contributor
timestamp: December 10, 2018, 01:01:28 am
content: Very cool job. Must be nice to be able to make your own gears.

author: VK5RC
author_rank: Unknown
timestamp: December 10, 2018, 04:29:24 am
content: First time and in plastic! Was quite a steep learning curve, I had never heard of a gear's modulus before! Still a bit vague really.I couldn't find any gear even close on eBay etc
Weird circuit in children toy - Page 1
Forum section: electronics / repair

author: frenky
author_rank: Unknown
timestamp: December 09, 2018, 07:37:54 pm
content: I have bought a bathtub toy which has a water pump in it and it stopped working on the first day.I thought pump has died so I took it apart to see which model should I order online.After a month I got it and replaced the faulty one.But this new pump also was not working so problem was elsewhere.I took it completly apart and found capacitor in series.I have never seen that in DC circuit. Any idea why the cap is there?The whole circuit is battery, capacitor, switch and 5v dc pump in series.

author: frenky
author_rank: Unknown
timestamp: December 09, 2018, 07:44:36 pm
content: The toy is powered by 3xAA batteries and pump looks like this:And toy:

author: David Hess
author_rank: Super Contributor
timestamp: December 09, 2018, 08:01:32 pm
content: The part is not a capacitor. It might be a PTC thermister used as a resetable fuse to prevent damage to the battery in the event that the motor seizes.

author: frenky
author_rank: Unknown
timestamp: December 09, 2018, 09:10:33 pm
content: That makes sense. Perhaps its to low value and its limiting current too much. Because pump was working but it did not produce enough water pressure to spin the accessories.
Motorola Moto G6 - Water Damage, part blown away - Page 1
Forum section: electronics / repair

author: ra-ma
author_rank: Contributor
timestamp: October 31, 2018, 10:11:50 am
content: Hi, after water damage and cleaning there’s a missing part on the motherboard of my Moto G6. Interestingly enough the phone works (Screen, Wireless, etc.) except GSM/LTE network access. Therfore I do have hope that it can be repaired.I’d need a schematic trying to fix it. If you look at the picture there’s abviously one part blown away (lower right) and in the upper left section there’s also some corrosion. I cleaned it up and it looks much better now, but the part in the lower right section is just gone…

author: ra-ma
author_rank: Contributor
timestamp: December 09, 2018, 03:52:20 pm
content: Hi All,another try: as I can't find a schematic: Does anybody have a high resolution picture of the area in question?Thank youMarco

author: JKKDev
author_rank: Regular Contributor
timestamp: December 09, 2018, 08:42:55 pm
content: Are any of the components around the blown up part identifiable (that chip in top left for example)? You could try figuring at least the type of the component missing that way.
HP 3312A pushbutton covers and knob - Page 1
Forum section: electronics / repair

author: belzrebuth
author_rank: Frequent Contributor
timestamp: December 20, 2018, 01:44:16 pm
content: Hi all,I've just received a HP3312A from eBay that has some signs of abuse namelytwo of the range push switches' covers are broken off and one vernier top knob is missing.The vernier pot itself is okay and the switches work fine too so it's purely cosmetic but I'd like to get this thing in better shape.Does anyone know where I could find these pushswitch covers or the knob?Compatible are fine so no need for HP spares as long as they fit.
Huntron Tracker TR 200 failed after first powering after long long time. - Page 1
Forum section: electronics / repair

author: Hrvoje_CRO
author_rank: Regular Contributor
timestamp: December 08, 2018, 10:29:50 pm
content: Hello!So today i've had urge to check my cca. 15y old Huntron Tracker TR 200 after not being used for around more than 5 years. And guess what? Magic smoke escaped! So i've opened it and found tantalum capacitor burned out and now entire unit is dead.So what i'm asking myself is: is it possible that in electronic equipment which is not used for a longer period, failure rate increases?And if yes, as in my case tantalum capacitor failed so what if field crystallization caused it to failure?Or, any other component failed and "pulled" cap to fail? I hope that is not a case!Thank you in advance!Hrvoje

author: t1d
author_rank: Super Contributor
timestamp: December 09, 2018, 02:26:41 am
content: Cap failure in older devices is just plain common. You can google as to why this happens. Electrolytic caps are notorious. Tantalum, too. I think it very likely that if you replace the bad cap that the unit will work again. You will want to inspect all of the caps and replace any that are suspect. It is not unusual to just replace all such caps as a routine maintenance matter, in old equipment. Pictures would help.

author: JFJ
author_rank: Regular Contributor
timestamp: December 09, 2018, 04:10:25 am
content: The Huntron Tracker TR 200 is also known as the Tektronix TR210. The TR210 service manual can be downloaded from here:https://www.tek.com/tr210-manual/tr210-service-manualIt doesn't include schematic diagrams, but a schematic for the main PCB is available from here:http://www.huntron.com/privatesales/technical/tracker200-main-pca.pdf

author: Hrvoje_CRO
author_rank: Regular Contributor
timestamp: December 09, 2018, 09:12:41 am
content: Quote from: JFJ on December 09, 2018, 04:10:25 amDear JFJ, i know about Tektronix TR210, i don't know how can i thank you, you got a beer from meThank you guys so much!Regards,Hrvoje
HP 54502A saving calibration with battery change? - Page 1
Forum section: electronics / repair

author: Tim88
author_rank: Regular Contributor
timestamp: December 11, 2018, 12:11:46 am
content: Picked up a super clean HP 54502A scope cheap. Bought it assuming it was not functioning. Turns out, it was just a bad contact in the power switch. Anyways, the date code on that Dallas chip is 1992 and evidently, the battery still works. Was gonna dremel in a new external battery and wondered if I should try to save the calibration settings with a TL866A programmer? The calibration seems spot on and didn't know if it recalibrates itself with a new battery or I should save the memory?Thanks!

author: dzseki
author_rank: Frequent Contributor
timestamp: December 11, 2018, 08:33:09 am
content: Either way. You can back up the memory, but it can also self calibrate with only a BNC cable.
Identify i component - on broken scoringtable computer - Page 1
Forum section: electronics / repair

author: Tony.T
author_rank: Regular Contributor
timestamp: December 08, 2018, 10:55:26 pm
content: We have a huge scoringboard for indoor hockey. it is wireless connected to the computer (http://www.westerstrand.se/sport/multi/LED300.htm) . Like this but i newer one.The battery does not charge and even if the powercord is connected to the unit it hangs and reboots, like it does not have enough power. If i disconnect the internal battery and use only powercord directly iw works without crashes.Soo something is wrong on the batteryside. if the external powersupply is connected, some leds are turned on. INdicating that it is connected to a powersupply. the strange thing is if the internal battery is connected...and i turn off the computer on a switch. These leds are still on...draining the battery totally. The internal battery should be 3.6V but was only 3.2, which is way to low. But one can not turn of the leds and it drains the battery totally.Ans as i mentioned before....disconnecting the internal battery makes everything work again and the computer does not shut it self down anymore.Tried to probe on a capacitor. the capacitor on the bottom of the picture is shorted. Removed it and it was not anymore....but tha pads are. Both ar connected to the ic visible in the picture. But i can not find what kind of IC it is.Could someone please help me here? This IC is directly connected to the pins from the internal battery...soo it must be something to do with that. I thing something is shorted there.Thanks...

author: sd
author_rank: Unknown
timestamp: December 09, 2018, 03:36:48 am
content: That looks like a BQ24060.
Need help identifying this component (pics) - Page 1
Forum section: electronics / repair

author: billbyrd1945
author_rank: Regular Contributor
timestamp: December 07, 2018, 02:35:34 am
content: I've been working on a wine cooler for a month or more. I suspect I have two bad transformers, but rookie enough to be unsure whether they actually are transformers. I'm posting a picture of one of the boards and its "transformer". I've Googled the number to death, but, can find no source for it. If I could, I would know for sure what they are and how to order them. I've checked them with meter out of circuit and found both coils to be open. Thanks for any help.

author: xavier60
author_rank: Super Contributor
timestamp: December 07, 2018, 02:54:03 am
content: The component in the first photo is a common mode choke, often called "hash choke". They rarely fail. It has a simple construction of 2 equal windings.That power supply has the same topology of early XT/AT PC power supplies. Start up relies on the half bridge power transistors self oscillating.If one or both of the 150K start up bias resistors are open, the large HVDC reservoir capacitors are likely to still be charged.Take care to not touch anything until you have checked.

author: billbyrd1945
author_rank: Regular Contributor
timestamp: December 07, 2018, 03:43:24 am
content: Thank you sir! Back to the drawing board.

author: floobydust
author_rank: Super Contributor
timestamp: December 07, 2018, 05:05:27 am
content: I found a schematic for that FX-101 and FX-102A Wine Cooler control board.

author: Armadillo
author_rank: Super Contributor
timestamp: December 07, 2018, 08:22:35 am
content: Looks like a pretty hard working C16.

author: billbyrd1945
author_rank: Regular Contributor
timestamp: December 07, 2018, 05:10:57 pm
content: "I found a schematic for that FX-101 and FX-102A Wine Cooler control board."WOW! Thank you! Never expected this!

author: floobydust
author_rank: Super Contributor
timestamp: December 07, 2018, 07:05:39 pm
content: Quote from: Armadillo on December 07, 2018, 08:22:35 amYes the 12V filter capacitor works very hard and has a short life.Some of these wine cooler controllers use a MCU while this one looks strictly analog.Replacement boards are also cheap to buy on Ali or eBay.These wine coolers just don't last, they run 24/7 and the Peltier cells can go bad too.

author: Armadillo
author_rank: Super Contributor
timestamp: December 07, 2018, 07:54:48 pm
content: Agree, its alternating either between 85V or 160V depending on the supply voltage.It should be a big polyyester capacitor for that purpose.Quote from: floobydust on December 07, 2018, 07:05:39 pm
Fixing Atten 8586 not reaching set temperature - Page 1
Forum section: electronics / repair

author: cyborg16
author_rank: Contributor
timestamp: December 07, 2018, 06:54:31 pm
content: Hi. I saw several people asking for the same problem a few years ago, and since I wasn't able to find the solution for this model here it goes.Since I changed the heater element of my solder iron I needed to set the temperature way higher than before, so I tried calibrating it with the preset meant to do that, but I couldn't get anywhere close (150ºC below the set temperature at max temp)I'm not really sure about it, but apparently the thermocouple in the new heater element is not quite the same than the original, so the circuit never gets to the real temperature.To fix that you simply have to add a 56K resistor in paralell to R29 (27K) or change the original to about 17K (for that you'll have to desassembly a lot more). This isn't very rigurous, I know, but the results are quite acceptable.The linearity is good and the preset now is able to regulate above and under the set temperature.In the pictures you can see the modification and a few meassurements.Cheers.PD: sory for bad english
Sony PVM-20M4U Power Supply Degaussing Circuit - Page 1
Forum section: electronics / repair

author: eccoboy
author_rank: Newbie
timestamp: December 08, 2018, 08:03:44 pm
content: Sony PVM-20M4U degauss circuit has failed. So far I replaced the relay and measured 210 ohms across the thermistor. I swapped the entire power supply from another monitor and degauss worked so I know the coil is still good. Not sure what to check next...https://www.manualslib.com/manual/1303987/Sony-Pvm-20m2u.html?page=42#manualhttps://www.manualslib.com/manual/1303987/Sony-Pvm-20m2u.html?page=64#manualfixed
Tefal Optiss BC5000V1 Kitchen Scale - Page 1
Forum section: electronics / repair

author: Jompy
author_rank: Newbie
timestamp: December 07, 2018, 01:03:38 pm
content: First of all, let me say that I am a very new to electronics as a whole so you might need to explains things a bit more than normalNow, I've got a Tefal Optiss BC5000V1 kitchen scale that is sort of dead. When the batteries are plugged in (as soon as the batteries are in, without pressing any buttons) all the display shows is "1.0". None of the buttons do anything at all, it does not auto-power off nor does it power off using the power button.The scale has a sensor on each foot and three (capacitive) buttons. I have attached a picture of the innerings of this thing (file too big, put it on imgur here:https://imgur.com/a/pcjaY2v).Not quite sure if I'm doing this correctly, but I tried to measure the voltage on each of the labelled solder joints (with batteries in) by putting the multimeter's COM lead on the negative battery wire and the other lead on the solder joint being measured.These are the voltages measured (+ red cable, - black cable)Top left foot:+ 1.18V- 0.6VBottom left foot:+ 2.37V- 1.76VTop right foot:+ 0.00V (expect this will be the problem)- 0.6VBottom left foot:+ 1.18V- 1.76VLeft side white cables: 1.76VRigth side white cables: 0.6VBased on the pattern, I would expect the top right foot + to be getting 2.37V but that's not happening, which I expect might be the problem. However not really sure where to go from here. Any help would be appreciated.I'm more interested in learning about electronics than actually fixing this thing which has been broken for a couple years. But if I manage to do both in one go, even better!
N-channel JFET info - Page 1
Forum section: electronics / repair

author: w2aew
author_rank: Super Contributor
timestamp: December 06, 2018, 12:34:15 am
content: My google-foo is failing - can't seem to locate any data or replacement info for this N-channel JFET. Most searches result in finding a Programmable Unijunction Transistor, but I know for sure that it is a N-channel JFET. Of course, it pre-dates the internet... Can anyone help?

author: Chris56000
author_rank: Frequent Contributor
timestamp: December 06, 2018, 01:00:33 am
content: HiiIt's Samsung coded but not a direct copy of a more well–known 2N–etc., device!If you do need to replace it, PN4393, BF256, 2N3819, etc., would probably do!Chris Williams

author: w2aew
author_rank: Super Contributor
timestamp: December 06, 2018, 01:26:07 am
content: Quote from: Chris56000 on December 06, 2018, 01:00:33 amThanks! I'll have to see which of them come closest to what I measured on the curve tracer.Where did you find the info?

author: Chris56000
author_rank: Frequent Contributor
timestamp: December 06, 2018, 10:43:17 am
content: Hi!My own personal store of device specs and equivalents gained from over 35 years doing Audio, TV and Industrials!There is also:–2SK30, and the J100, J200 and J300 series as well! Most JFETs rarely require a voltage rating of more than about 25–30V!As you have access to a C.T., it might be worth checking eBay, AliExpress, Bangood, etc., etc., for cheap "goodie bags" of 10–20 or so and trying a selection, then marking their tops with a little dot of paint from a paint marker and keeping 'em in a clearly labelled bag!Chris WilliamsPS!If the FET you showed us came out of a meter or similar piece of T & M, you might require one with low leakage characteristics, in which case, the parameter to look at is "Igss".The E200/E300 and J208/J209 are characterised for low gate–leakage, and there's others as well!If you need to check Igss, bias the gate about –3V with respect to source and interpose a 10M resistor in series with the gate lead – 1nA leakage will drop 10mV across a 10M resistor!You'd need a nanometer with an electrometer–type input amplifier to try and measure Igss directly – Keithley 616/617 for instance!

author: CHexclaim
author_rank: Regular Contributor
timestamp: December 07, 2018, 06:50:01 pm
content: BTW, from the picture, great PCB design! ... or not.

author: w2aew
author_rank: Super Contributor
timestamp: December 08, 2018, 03:47:56 am
content: Quote from: CHexclaim on December 07, 2018, 06:50:01 pmYeah, NOT! I bent the JFET over to get a better picture. Single layer PCB, no silk-screen, but then again, the instrument is likely almost 40 years old.
Pioneer PDP-LX5090 with 8 red blinks – Repair - Page 1
Forum section: electronics / repair

author: rosherman
author_rank: Newbie
timestamp: December 05, 2018, 04:50:18 pm
content: Hi,My Pioneer PDP-LX5090 (manufactured in UK, 2008) has the following issues:1. After watching TV for a few hours (~2-3 hours) it suddenly turns off and the red indicator light blinks 8 times, stops for a few seconds and starts blinking again (8 times) and so on.2. If I disconnect it from the power supply, and after 2-3 minutes I connect it. When I try to open the TV it feels like it starts (the blue light is on) but after a second it turns off and the red blink starts again.3. When I disconnect it from the power supply and then wait a couple of hours and then re-connect it, the TV works again.Appreciate if someone here can help me with this problem.

author: Chris56000
author_rank: Frequent Contributor
timestamp: December 05, 2018, 11:06:41 pm
content: Hi!S.M. first:–https://elektrotanya.com/pioneer_pdp-lx5090_arp3480.pdf/download.htmlTraining Guide:–https://drive.google.com/open?id=1Z8nBBLRi49GJ-OaabpBXlB38PyOkW7bEPioneer don't provide detailed component–level circuit diagrams unfortunately as they consider the PCB assemblies to be non–repairable, but there's plenty of information in the two documents I've linked to help you trace the location of the fault!Then begin by examining the power supply board for bulging or just "tired" electrolytics, any overheated resistors or other components that might point to semiconductor faults elsewhere, then check ALL power supply rail voltages against those stated in the service manual.Please note – the digital and signal processing boards, etc., may have their own voltage regulators and the outputs from these will need checking as well!Have a read thro' these and a good look at your boards, follow thro' the diagnostic and fault–finding charts Pioneer provide, then come back by all means if you're still stuck!Chris WilliamsPS!Don't forget this TV would almost certainly have had the boards assembled in the factory with that "lead–free" muck, so you've got the old bogey of dry–joints, etc., which, unfortunately, could literally be anywhere, but connectors, heat–sinked transistors and ICs, transformers, large electrolytic capacitors, anything running hot., etc., etc., are the places to look first!A good illuminated magnifier is your best friend here – RS Components do a good German–made one for about £9!
fujitsu siemens bios flash - Page 1
Forum section: electronics / repair

author: kokodin
author_rank: Regular Contributor
timestamp: December 07, 2018, 10:06:36 am
content: hello therei have a project that need someone help, because i am going crazy with how oem and internet forums works these dayproject isi want to flash bios file from a fujitsu siemens d2904 motherboard into d2724 boardseems simple enoughflash chips are the samechipset configuration and most of hardware is the samewhat is different is cpu support list and tweaked cpu power delivery on the pcb (not a problem really)but there start some stairs1 fujitsu only distribute bios files in compressed format and embeded decompressor in flashing program and it knows it isn't that motherboard2 bios update is only made out of patches so.. i don't think i can even make flash file out of that3 motherboard is wierd and 3rd party programmers do not like it, they do work , but not happyi have found this cryptic post from few years agohttps://forums.mydigitallife.net/threads/update-fujitsu-esprimo-e5625-bios-to-support-amd-am2-am3-c3-revision-processors.58787/and atempted to understand iti got the mentioned decompressing softwaregot the mentioned flashing software (probably outdated version)i flashed bios on the d2724 board with the newest bios avalable using oem flashing soft revision 02 to 08 with successi read that flash from the bios using mentioned 3rd party flashing grogram it was not happy that it does not know the computer brand and stuff though had to be forcedused mentioned decompressing software to make the same bios file into a flash fileand opened both flash files in hex editor before going any furtherlet's just say the flash i read from motherboard and the one i created with decompressing tool look vastly different even if they are suposed to be the same bios revision for the same motherboard (there are some common areas but not much), therefore i don't think flashing motherboard with created replacement bios is a good idea at this point because i have no way of veryfying if it is even a correct flash for the bios (i have no way of checking if flasher messed up or if creator messed up, but it look more like creator i can read some text in flash i backed up in plain english eg company names and some hardcoded string values)problem is i want to make an atempt and i need some ideas how to do itany help would be apriciated
Ct system (wavetek) CTS 5100 Service monitor  - Page 1
Forum section: electronics / repair

author: Ka9gfs
author_rank: Newbie
timestamp: December 05, 2018, 04:47:11 pm
content: I have acquired a new to me service monitor wavetek CTS 5100SI have had no luck in finding any information as of now, Does anyone in the world have anything available for this piece of equipment?The company has since went out of business and I am desperate for anything.DavidKA9GFS
Tektronix TDS754C one channel showing some offset - Page 1
Forum section: electronics / repair

author: MattiaM
author_rank: Newbie
timestamp: December 04, 2018, 12:15:55 pm
content: I have been using a GW Instek oscilloscope for quite some time now, and when I found online a Tek TDS754 for sale at an incredibly low price, I decided to buy it, even if it was listed for parts; acording to the description, channels 1 and 2 did not work. However, given that it passed all self tests, I decided to go ahead with the purchase.Once I received the scope, I started looking into the problems and, at first, I could not get anything from channel 1 and 2. After a factory reset, they both work and display signals correctly. The scope passes all self tests (signal compensation, voltage reference, freq. response, pulse trigger).The issue is this: Channel 2 visualizes voltages properly only if the vertical scale is set to 2V per division or greater. As soon as I set the vertical scale to 1V per division or less, the signal gets an offset of about +2.7V (with no input, the line visualized shifts up to +2.7V), and it stays there. With the vertical scale set to smaller values, the signal eventually goes off scale. If I have a waveform displayed, the amplitudes remain the same, just with the added offset. The trigger levels also need to be increased by that offset for the trigger to work. Between 1V and 2V per division, a relay clicks.What could that be?Thanks.

author: eKretz
author_rank: Frequent Contributor
timestamp: December 05, 2018, 05:19:18 am
content: There are relays in the signal path that divert the signal to different paths depending on voltage setting. They are a common failure point in these scopes. It's possible that a relay with excess on resistance could be causing issues. Usually this shows up as an SPC error though.
Bunch of electronics in brisbane - Page 1
Forum section: electronics / repair

author: Shoota75
author_rank: Newbie
timestamp: December 05, 2018, 02:19:06 am
content: Cleaning out my garage and have a bunch of old caps resistors switches chips and more looking for someone who is a learning as im 43 and a telecommunications network engineer and don't have the time for it anymore.

author: TERRA Operative
author_rank: Super Contributor
timestamp: December 05, 2018, 03:43:24 am
content: What sorts of chips? I might be interested in any old silicon.

author: Shoota75
author_rank: Newbie
timestamp: December 05, 2018, 04:16:50 am
content: sorry they where the first to go, I think only some Motorola "or gates" are left mc74hc32n and mc1488p line driver

author: Shoota75
author_rank: Newbie
timestamp: December 05, 2018, 04:24:42 am
content: pic2 would love to find a young person who is starting out like Dave did in his shed and understand some of the old school gear as well as the new.
RT809H AND TV BRAVIA - Page 1
Forum section: electronics / repair

author: lionelkjh
author_rank: Frequent Contributor
timestamp: December 03, 2018, 06:33:01 pm
content: Good evening everyone! I just received my RT809H programmer with many supports to house the integrated circuits. But, I have to regret a nand on a tv SONY BRAVIA, and the problem is that the programmer supports only bin: gold, sony could send me 2 soft, 1 to write the new program in the nand , and the other, to install the app, but these 2 files are in the format upd. How to install them in the nand? Should you convert them? Another remark: I have the choice between desoldering the nand and reprogramming it, to put it back on the motherboard; or put a RS232 cable to do the reprogramming directly (easier): but how to doCan someone help me? Thank you for you precious help

author: shakalnokturn
author_rank: Super Contributor
timestamp: December 04, 2018, 08:29:35 pm
content: Maybe you'd get more useful input by giving the TV model, fault history, symptoms, target processors for the software... Posting or linking to the .UPD files...You could consider looking at your .UPD file with a hex editor, that may give you some clues as to whether it is worth trying to rename and flash the files as plain binary .BINOf course if they are compressed in any way you're into trouble...Your google translate is sometimes a little hard to follow even for a French speaking person.Here is a French speaking forum where there are a few people knowledgeable on LCD TV's.https://www.répartout.com/
Omnicure S1000 Light Bulb problem - Page 1
Forum section: electronics / repair

author: hl68fx
author_rank: Newbie
timestamp: December 03, 2018, 08:04:44 pm
content: Hi everyone,we are using an Omnicure S1000 in our lab and since today its light bulb does not work anymore because it reached 2000 operating hours. We have already ordered a new bulb but the delivery time is ~4 weeks. At the back of the bulb there is a PCB with a chip and three wires. I have attached a picture of it.I could not find a datasheet of the chip on the PCB. I am not sure what this chip does, maybe it is some kind of timer?I have read the manual and it does not seem to be possible to reset the device. Disconnecting the cable did not work either.Do you have any idea how I could cheat to get the bulb working again until the new one arrives?Kind regards,Tom

author: Bashstreet
author_rank: Frequent Contributor
timestamp: December 03, 2018, 08:27:02 pm
content: Unlikely.The pulps are designed to have nominal lifespan and after reaching this will cease to function.Cheers.Ps: Remember to order few spares.

author: wraper
author_rank: Unknown
timestamp: December 03, 2018, 08:44:42 pm
content: It should be possible but without working lamp at hand I would give up on cracking protection. The only way I see getting it working is brutally hacking the device itself.

author: wraper
author_rank: Unknown
timestamp: December 03, 2018, 08:48:05 pm
content: Quote from: Bashstreet on December 03, 2018, 08:27:02 pmIt's just an electronic time bomb. The same as with printer cartridges and drums. The fact timer run out does not mean that lamp itself is bad.

author: hl68fx
author_rank: Newbie
timestamp: December 04, 2018, 07:27:34 am
content: Thank you very much for your replies! I am sure the bulb is not broken and I know it has less intensity then a new one but that is ok for our current purpose.The bulbs are really expensive so it is not a part which you have several times in stock. I do not think it is ok to sell things with "electronic time bombs".Is there a way to reset the timer?

author: Bashstreet
author_rank: Frequent Contributor
timestamp: December 04, 2018, 04:05:36 pm
content: These lamps are designed have specific lifespan and are not to be used after reaching the limit.Timer is there to prevent exposure from the mercury vapors and contamination as result of exploding pulp.
Gaggenau appliances list of error codes - Page 1
Forum section: electronics / repair

author: CHexclaim
author_rank: Regular Contributor
timestamp: November 30, 2018, 04:25:29 am
content: Hello. as you may have seen from a previous post I have a couple of Gaggenau appliances that malfunction, thus I require their service manual which seems to be made of unobtanium.Anyhow, as a start I would appreciate if someone can help me with a list of the error codes, as, of course, none of the error codes that show up are listed on the user's manual.Thanks, Carlos.

author: CHexclaim
author_rank: Regular Contributor
timestamp: December 07, 2018, 06:46:30 pm
content: No one?? Are these so obscure?Thanks, Carlos.

author: tsman
author_rank: Frequent Contributor
timestamp: December 07, 2018, 06:57:15 pm
content: You should try asking on appliance repair forums. I don't think there are that many appliance repair engineers on here so it isn't that people are ignoring your request, they just don't know the answer.

author: CHexclaim
author_rank: Regular Contributor
timestamp: December 07, 2018, 07:00:13 pm
content: Good point, Thank you.Carlos.
Anyone successfully use Microwave Oven HV diodes for a Scope voltage multiplier? - Page 1
Forum section: electronics / repair

author: Not_Sure
author_rank: Newbie
timestamp: December 03, 2018, 11:44:32 pm
content: Hello,I am wondering if the very inexpensive CL01-12 type Microwave oven HV Diode would be suitable to use in a DIY voltage multiplier for a Tek 465. I have been unable to get any information on the TRR of this type of diode as the datasheets don't spec it or leave a value out. I assume its either not tested, or very slow, maybe both but searching has revealed nothing about this class of HV diodes.Thanks,Not

author: xavier60
author_rank: Super Contributor
timestamp: December 04, 2018, 01:32:52 am
content: The diodes used in Panasonic MW inverters are likely to be faster. They operate at up to about 40Khz.

author: xavier60
author_rank: Super Contributor
timestamp: December 04, 2018, 01:54:22 am
content: Not cheap though,https://www.wagneronline.com.au/panasonic-stack-diode/microwave-parts/service-repair-parts/ux-c2b-3644/960833/pd/I tested one here. It takes 60ns to recover from 20ma forward bias.Years ago I used much smaller diodes to build a split winding flyback EHT supply for a BWD oscilloscope. They were about 1cm long and pointed at one end. I think they were for small black and white TVs.

author: Not_Sure
author_rank: Newbie
timestamp: December 04, 2018, 03:28:36 am
content: Check Ebay or Amazon or AliExpress. From China they are ~$1/ea. In the states its more like $1.50 if you look around and buy in 5 or 10 each lots.

author: floobydust
author_rank: Super Contributor
timestamp: December 04, 2018, 03:50:01 am
content: 350mA diodes are way overkill.For a scope you don't need over 5mA, typically a2CL73is used as an example. 5mA 12kV 100ns but get the longer 17mm parts if you are not potting the whole thing. Lots of 10mm sized parts for cheap on Ali or eBay.Panasonic Inverter microwave I took apart usedSanken UX-F5Bpretty big 350mA at 8kV PIV 150ns fast-recovery. A bit low on PIV I think.
Piss poor design of Air Vent Inc "Enviro-Stat" attic vent sold at home stores. - Page 1
Forum section: electronics / repair

author: 1sciguy
author_rank: Contributor
timestamp: November 29, 2018, 08:48:46 pm
content: Bought the latest and greatest powered attic ventilation fan from Air Vent Inc. Paid an extra $60 for their "high efficiency variable speed" model. Fan is microprocessor controlled and vents the attic based on temperature and humidity. Install is simple enough, cut a hole in your roof, wire it up and it automatically runs. Seemed great at first. I finished my install in the afternoon in Charleston SC and it turned on and ran at a nice controlled speed to vent the heat buildup. As the temperature dropped, the fan slowed and eventually stopped.Day 2. Woke up at 5am because I heard what appeared to be a freight train. Strange, because there are no train tracks on my island. It was that damned air vent. There was a fog outside and it set off the humidity sensor. This, of course, draws in more cold damp air and the fan wants to run even faster. The damn thing went to full speed and was never going to stop on its own. It would continue to draw cold moist air into my attic. I turned it off and since I had already cut the hole in my roof there was no way I can remove it an return it. Removed the motor because everything is built into the motor. The motor has a small humidity/ temperature sensor sticking out the side.Day 3. Called Air Vent Inc. Let me tell you, the representative on the phone was about a rude as I have ever heard. Bottom line, they had no engineer that they could let me talk to. I simply wanted to know if the sensor they used was a digital sensor with I2C communication or was it an analog sensor. If analog, I would have cut the humidity signal wire.Today I looked up the patent number written on the motor and found out it is made by McMillan Electric in Wisconson. Called them and spoke to an engineer. Engineer confirmed it was an I2C chip, so there is no way to disable "only" the humidity function.Anybody have any great ideas about coating a humidity sensor? Dry it out and then apply a varnish or hot glue? Maybe put it in another tube with a desiccant inside? If I can't disable the humidity function of the fan, I will have to add a second thermostat so the power to the entire fan is only present when the attic is over 80 degrees.

author: fixy88
author_rank: Contributor
timestamp: December 01, 2018, 04:43:39 am
content: I'd be hesitant to coat it directly - I would just seal it in a small air space somehow when the humidity is low, or as you say add some desiccant to the air space you seal it in.

author: SilverSolder
author_rank: Super Contributor
timestamp: December 01, 2018, 06:17:26 pm
content: If it is an I2C sensor, you may be able to use a shielded cable of some kind and move the sensor to a better location?It seems reasonable enough that if moisture is detected in the attic, the fan should keep going? We just don't want it to get triggered by the weather outside, if the attic itself is dry - right?
Yihua 995d+high resolution photos please  - Page 1
Forum section: electronics / repair

author: solderjoint
author_rank: Newbie
timestamp: November 29, 2018, 10:09:04 pm
content: HiAllI have a Yihua 995d+ 2 in 1 soldering station that is not workingThe soldering iron part of it does not turn on when I press the SMD tact switch, there is a red wire going from one of the legs but where it goes has snapped off.I was wondering please if anyone has any high resolution photos of the yihua 995d+ of the inside on the same side of the LCD and on the other side please.This is so that I can trace where the red wire goesI will really appreciate it pleaseThanks so much in advance

author: solderjoint
author_rank: Newbie
timestamp: November 30, 2018, 11:34:33 am
content: HiPlease can anyone help

author: Rasz
author_rank: Super Contributor
timestamp: November 30, 2018, 11:59:01 am
content: buy cheap(shit) buy twice

author: solderjoint
author_rank: Newbie
timestamp: November 30, 2018, 01:30:06 pm
content: I saw these videos but i can't see any components or wires On the pcb boardCan anyone take photos of the 995d+ and upload pleaseOr tell me what the wiring is for the smd tact switch to turn on the soldering ironThanks

author: solderjoint
author_rank: Newbie
timestamp: December 01, 2018, 01:35:49 am
content: HiAll
Repair of stick welder, can't find suitable IGBT replacement - Page 1
Forum section: electronics / repair

author: Snake____1
author_rank: Contributor
timestamp: November 27, 2018, 12:21:24 am
content: Hello,My stick welder stopped working and I have narrowed it down to the IGBT module pack, problem is I can't find any replacement or even datasheet for that matter. I have attached an image of the IGBT module, the only number I can get any hits of is: P280B57.Can anyone here help a fellow DIY'er out?

author: tautech
author_rank: Super Contributor
timestamp: November 27, 2018, 01:52:25 am
content: Can you do a pic of the pin out please ?

author: coromonadalix
author_rank: Super Contributor
timestamp: November 27, 2018, 05:26:53 am
content: model and brand name may help too, be more descriptive thks

author: Housedad
author_rank: Frequent Contributor
timestamp: November 27, 2018, 06:27:48 am
content: It looks a whole lot like a Vincotech part, but that part number did not come up. I agree. What maker of welder? Age? Tig, mig, or stick? Declared amperage of welder?

author: Snake____1
author_rank: Contributor
timestamp: November 30, 2018, 11:33:58 pm
content: Quote from: tautech on November 27, 2018, 01:52:25 amPinout is all over the place, the dismantling of the IGBT pack was more or less destructive as I had to snip the pins. Some of the pins came lose from the IGBT pack and was left on the PCB...Quote from: Housedad on November 27, 2018, 06:27:48 amIt may be a TYCO P280B57 part, hard to get a hold of a retailer. This is a stick "MMA" welder, Fronius TP1100. Maximum 110A.

author: PaulAm
author_rank: Frequent Contributor
timestamp: December 01, 2018, 12:26:58 am
content: There's a listing on Alibaba for that, might be worth a chance if nothing else turns up.
Let's talk old Darlingtons: Looking for a sub for PMD10K40 - Page 1
Forum section: electronics / repair

author: cvanc
author_rank: Frequent Contributor
timestamp: November 30, 2018, 04:44:36 am
content: I'm thinking 2N6384 but wondered what the braintrust here thought. It's for an old 5V bench supply and is driven by a 723 regulator IC.(yup, it's that old, I was just amazed to find the 723 is still being made!)Datasheet for the PMD10K60 attached; it's the closest document I could find. Thanks.

author: floobydust
author_rank: Super Contributor
timestamp: November 30, 2018, 05:19:07 am
content: I don't see much critical for a substiture pass transistor in a linear power supply, other than safe operating area.How many amps is the 5V output? Raw DC voltage is? If you really want to dig in, a schematic helps. Otherwise, just use brute force and put in a beefy part with similar speed and enough hFE so that the LM723 is not loaded much.2N6284is low cost and has SOA curve to check, and 160W rated.MJ11012is stronger SOA and 200W rated.
Agilent E4402B Spectrum Analyser no 10Mhz reference output on rear connectors - Page 1
Forum section: electronics / repair

author: djsb
author_rank: Super Contributor
timestamp: November 26, 2018, 08:50:22 pm
content: I have retrieved an Agilent E4402B spectrum analyser from a skip. I have no 10Mhz reference (should be 0dB) signal on the rear BNC connector only a low frequency low amplitude sine wave (there is a 10MHz external input next to it as well). Also there appears to be a 10Mhz high stability output socket as well (Option??) but no output on that BNC socket either.The instrument seems to work OK but it's frequency accuracy seems a bit off and it probably hasn't been calibrated in a while. I've just fitted a new internal battery/crystal and now the Real time clock and date is OK.I have a service manual but don't know how to narrow down the problem or if it can even be fixed. Not sure if the 10 Meg clock ref output is always meant to be available on the rear outputs or if it needs to be switched on. Can anyone suggest where I should look for clues? Thanks.

author: orbanp
author_rank: Regular Contributor
timestamp: November 29, 2018, 03:30:53 pm
content: Hi David,Here is a service guide for that family of SAs, in case this is not the one you have:https://literature.cdn.keysight.com/litweb/pdf/E4401-90474.pdf?id=2439413Good luck, Peter
H55 motherboard damaged mosfet  - Page 1
Forum section: electronics / repair

author: lordicenova
author_rank: Newbie
timestamp: November 29, 2018, 04:55:28 am
content: I'm trying to fix H55 motherboard with a damaged mosfet. The damaged mosfet says k4213 ks07 but I can only find a k4213 ks08 online. Will this be fine for the motherboard or does it need to be the same? It's only 1 number off so it should be fine right? Or do all of them need to be the same?https://www.ebay.com/itm/5-PCS-2SK4213-TO-252-K4213-SWITCHING-N-CHANNEL-POWER-MOS-FET/291775690105

author: ElecSeb
author_rank: Regular Contributor
timestamp: November 29, 2018, 05:59:26 am
content: K4213=2SK4213I presume KS07/KS08/KS0? is date coding.However without a picture it is hard to tell...You already found the datasheets:https://alltransistors.com/pdfview.php?doc=2sk4213-zk_2sk4213a-zk.pdf&dire=_updatehttps://alltransistors.com/pdfview.php?doc=2sk4213.pdf&dire=_nechttps://media.digikey.com/pdf/Data%20Sheets/Renesas/Transistor_Thyristor_Triacs_Photocouoplers_StatusList.pdf

author: lordicenova
author_rank: Newbie
timestamp: November 29, 2018, 08:08:59 am
content: Here's a picture of the broken mosfet. The surrounding mosfets say the KS07 so I'm pretty sure this one is also 07. Sorry for the zoomed up picture site only lets me upload max of 1mb :/

author: ElecSeb
author_rank: Regular Contributor
timestamp: November 29, 2018, 08:18:58 am
content: I would bet KS0x is just date marking...I would replace with 2SK4213 or similar, especially when it is in powerline (just look for an alternative)

author: lordicenova
author_rank: Newbie
timestamp: November 29, 2018, 08:51:53 am
content: I'm not to educated on this but if it's just a date marking then the 08 I found on ebay would work too wouldn't it?

author: ElecSeb
author_rank: Regular Contributor
timestamp: November 29, 2018, 09:06:03 am
content: Not a big fan of ebay semicondutors...I cannot hand you a direct replacement. But look at the last link in my last post to see what the specifics are and then search in mouser/farnell/digikey for a replacement.Might be useful to check here on the board to have feedback on your search.Based on the info you should be left with a couple of alternatives...

author: Rasz
author_rank: Super Contributor
timestamp: November 29, 2018, 12:32:57 pm
content: just guessing, but I suspect you havent even pulled it off the board yet, start with thatthey usually work in pairs, so at the very least other one is also blown, or maybe also the driver, or the controller chip