hybridfree/eevblog-posts huggingface dataset:
Panasonic VP-7725D Audio Analyzer distorted oscillator  - Page 1
Forum section: electronics / repair

author: Ray Gianelli
author_rank: Contributor
timestamp: January 16, 2021, 02:48:23 pm
content: My distortion analyzer has started to output distorted waveforms at the oscillator output. While it at first appeared that this unit has two totally independent channels, it looks like they share a common oscillator.Compounding troubleshooting issues is the fact that the construction of the unit makes it virtually impossible to do any power on testing. The oscillator/attenuator assembly is on a plug in board beneath 2 other plug in boards.Attached is a pic of the distorted output.Here's a link to the service manual, which is impossible to find. Thankfully I got a copy when I purchased it:https://drive.google.com/file/d/0BxLVd1MVhl--ZTBMazRZd3RhWDg/view?usp=sharingAny help with this would be greatly appreciated!

author: schmitt trigger
author_rank: Super Contributor
timestamp: January 16, 2021, 03:17:43 pm
content: Are the board connectors a standard type?If so, you will require to build extension patch cables, which will allow you to have all the boards spread out on the work bench.

author: Ray Gianelli
author_rank: Contributor
timestamp: January 16, 2021, 03:24:20 pm
content: I've looked into that. They're available from most online vendors. The sockets on the backplane are Omron XC5B-6421, 6422 on the board, 2 of each required. Fortunately I just need the one board on the bench.

author: USMC_Spike
author_rank: Regular Contributor
timestamp: February 03, 2021, 08:40:02 am
content: I was looking for the pop corn guy to watch as you go along.Yes, there it is with a drink also.It's hard to get most of the Matsushita manuals for their gear.Heck I never found a service manual for the VP-7635p so there issits. The -p is for Panasonic, -A for National, and I think -m was forMatsushita. I can find a $100 parts unit but shipping is 250.I did find this manual number, don't know if it's correct,VP-7635A nat-qvp7635a.I put it here so I could find the number again.I think I only need the four latching input signal switches forthe meter to work, of course I don't have them.Good luck and hope your repair goes well.Spike
Pairing a Crest ultrasonic cleaner tank with another brand generator - Page 1
Forum section: electronics / repair

author: elemenoh
author_rank: Contributor
timestamp: June 08, 2024, 03:56:00 am
content: A friend gave me a Crest 4HT-1014-6 tank that would normally pair with a Genesis 4G-500-6 500W external generator. Those generators sell for quite a lot on eBay, even when super old and in terrible condition. Is it possible to pair that tank with a more generic generator?For instance, I saw this 600W one linked below on aliexpress, but it was unclear if it'd be compatible. The Crest tank only has a male BNC connector whereas the generic generator has a couple of different connections on the back side.https://www.aliexpress.us/item/3256803470867151.html

author: elemenoh
author_rank: Contributor
timestamp: June 10, 2024, 08:07:40 pm
content: I messaged Granbo Ultrasonics on aliexpress to ask if their generators are compatible with Crest tanks and they said:QuoteThat makes sense. I ended up getting a janky broken Crest generator from eBay for a decent price so am going to try to patch that up first before ordering a generator from Ali.
Part for HMP4040 - Page 1
Forum section: electronics / repair

author: seavan
author_rank: Contributor
timestamp: June 11, 2025, 04:54:18 am
content: Does anyone know where to get the encoder for HMP4040? I am considering to get a unit with a broken knob off ebayhttps://i.ebayimg.com/images/g/jrIAAeSwAbRoSDLf/s-l1600.jpg

author: Messtechniker
author_rank: Frequent Contributor
timestamp: June 11, 2025, 06:10:13 am
content: Since the HMP4040 is an ex Hameg unit, you might want to try (in Germany):https://www.sky-messtechnik.dehttps://allice.de

author: Halcyon
author_rank: Unknown
timestamp: June 11, 2025, 08:47:35 am
content: Duplicate thread:https://www.eevblog.com/forum/repair/rs-hmp4040-knob/
Part identication - Page 1
Forum section: electronics / repair

author: perdrix
author_rank: Frequent Contributor
timestamp: April 16, 2020, 04:55:58 pm
content: Silkscreen says it's a fuse (F1/F2/F3) and it is size 1210 with the top painted mid-green with an upper case letter A. Possibly a Littelfuse 1210L005 Polyfuse?Any other thoughts on what it might be?Thanks, David

author: gorge441
author_rank: Contributor
timestamp: April 16, 2020, 05:04:55 pm
content: If you give a photo of that then it will easier to detect.

author: perdrix
author_rank: Frequent Contributor
timestamp: April 17, 2020, 03:32:26 pm
content: Here you are:David

author: RoGeorge
author_rank: Super Contributor
timestamp: April 17, 2020, 04:07:41 pm
content: That's a fuse, and by its green color, probably a polyfuse, especially if it's placed near a USB connector, for example.

author: perdrix
author_rank: Frequent Contributor
timestamp: April 18, 2020, 04:17:14 am
content: Yes I know it is a polyfuse - its a matter of identification of the exact replacement ...David

author: aqibi2000
author_rank: Regular Contributor
timestamp: April 18, 2020, 09:02:09 am
content: If this is a laptop, give me the full motherboard number and model
Part identification - Hall sensor from Canon Elura 80 - Page 1
Forum section: electronics / repair

author: Miti
author_rank: Super Contributor
timestamp: September 11, 2019, 01:42:09 am
content: Hi,I need your help to identify a part that I damaged while repairing the LCD of a Canon Elura 80. It is a super tiny Hall sensor that detects the rotation of the LCD so the camera flips the image. There's a magnet in the fixed part and this sensor in the mobile part. The size is about 2x1.65mm with 5 pins.Marking is:10430Thanks!Edit: I forgot to mention it has 5 pins, I edited above.Edit2: It looks pretty much like a Panasonic AN48836 or AN48841 but I measure some resistance between pins 1 and 2 so I think both pins are connected in my case, unlike the two aforementioned devices.

author: fzabkar
author_rank: Super Contributor
timestamp: September 11, 2019, 05:43:08 am
content: Assuming that the part marking example in the AN488xx datasheet shows an AN48841, then the first line would suggest an AN48810. The second line would be a YWW (Year/Week) date code, possibly week 30 of 2014. Does that tally with the other date codes?Hall sensor IC - AN488xx series and others:https://b2bsol.panasonic.biz/semi-spt/apl/cn/news/contents/2013/embeddedworld/flyer/Hall_IC_EW13.pdfCould this be it?https://industrial.panasonic.com/content/data/SC/ds/ds4/AN48810B_E_discon.pdf

author: Miti
author_rank: Super Contributor
timestamp: September 11, 2019, 10:44:09 am
content: That must be exactly it.Thanks a lot sir!The good part, it is still available at Digikey.
Part identification help 4425 - Page 1
Forum section: electronics / repair

author: little.tesla
author_rank: Regular Contributor
timestamp: July 07, 2022, 06:59:29 am
content: Hello,I'm struggling to identify a dual OpAmp in MSOP-8 package with marking 4425 used in an analog circuit, where I'm very confident it's a low drift/noise component with the typical pinout. On the back side there is a marking like this: 1st line: NJAI 2nd line: 1919I've already searched for the markings and scanned the usual suppliers for similar types but without success so far.Any pointer or help is very much appreciated.Kind regards

author: gamalot
author_rank: Super Contributor
timestamp: July 07, 2022, 07:05:10 am
content: It's a MAX44251https://datasheets.maximintegrated.com/en/ds/MAX44250-MAX44252.pdf

author: little.tesla
author_rank: Regular Contributor
timestamp: July 07, 2022, 07:37:46 am
content: Looks like a perfect match! Thank you very much.May I ask how did you find it? Did you know this component from your projects or used some next level google-fu?

author: gamalot
author_rank: Super Contributor
timestamp: July 07, 2022, 08:43:59 am
content: Most of the time I go to taobao.com, which is more effective than google in searching for the top marking of the components.This time is a little different, yes you are right, I happen to have the MAX44251 on my desktop.
Part identification help needed - Page 1
Forum section: electronics / repair

author: elgatoguiri
author_rank: Newbie
timestamp: October 26, 2024, 05:16:50 pm
content: Hi,I've got this part in a logitech g27 shifter. It's a rotary / precision potentiometer but I can't find an exact replacement for it. I'd like to know what the letters and numbers mean and if I can replace it with another similar part.I've found the same one on aliexpress except the 0A is 8A. What does this matter and more importantly could it work in the shifter?Thanks a lot!
[SOLVED] Part identification, resistor? - Page 1
Forum section: electronics / repair

author: Edumcg
author_rank: Newbie
timestamp: June 25, 2023, 12:37:00 am
content: Can someone identify this component? Or perhaps explain what it is?I am referring to the big metal rectangle with only an R marking.If someone knows how to remove it, I would appreciate the explanationI figured I could heat it with a heat gun until it falls off but some guidance would be great.Thanks in advance.

author: mengfei
author_rank: Regular Contributor
timestamp: June 25, 2023, 01:10:54 am
content: looks like a Heatsink covering probably some Transistors or FET'swhat's on the other side of the PCB directly beneath that metal

author: xrunner
author_rank: Super Contributor
timestamp: June 25, 2023, 01:15:15 am
content: It might be a shield covering components. Look at the sides and see if you can see anywhere it's tacked onto the PCB with solder.

author: coromonadalix
author_rank: Super Contributor
timestamp: June 25, 2023, 02:49:46 am
content: seems a shield to me

author: Edumcg
author_rank: Newbie
timestamp: June 26, 2023, 07:14:44 pm
content: Attached picture of the other side.I think it is a heatsink for the big diode. It has a B30R marking and looks similar to this one:https://pdf1.alldatasheet.com/datasheet-pdf/view/58877/DIODES/B330.htmlWith some courage I managed to lift it up and it was covering nothing so I guess is just to dissipate heat in case the board becomes too hot.Thanks for your help

author: Edumcg
author_rank: Newbie
timestamp: June 26, 2023, 07:17:09 pm
content: With a little bit of courage I managed to lift it up starting from the sides as you said so, thank you.It was covering nothing but at least now I can see the paths and that helps on my quest to repair this thing.

author: coromonadalix
author_rank: Super Contributor
timestamp: June 27, 2023, 11:15:56 am
content: oh an added heatsink + thermal pad onto a pcb surface wowbut cooling an huge diode must be reverse protection or forward polarity protectionNothing fancy therebut you have some transistor, written FET301 on the pcb, seems kinda brownish around it ?, must be the one who get hot, the big resistor must get hot too ??Its a car radio?And the aluminum plate must touch the enclosure ... ?

author: Edumcg
author_rank: Newbie
timestamp: June 27, 2023, 06:42:40 pm
content: The FET301 seems ok, it doesn't look damaged.The big resistor does look brownish but it is because I remove it to measure it. It is a four band resistor with a color code red, purple, gray and gold but I think is faulty because sometimes it gives me a reading of 1.1 ohm, others a reading of 0.7 ohm. If I am correct it should be 0.27 ohm consistently.None of them get hot right now, when I turn it on the main power IC doesn't even get voltage on Vcc so I'm trying to figure out the path from 12V to the main power IC. Still no luck.Yes! It is a car radio. Oh you're right! When it's assembled the aluminum plate does touch the enclosure
Part identification Server PSU - Page 1
Forum section: electronics / repair

author: fatunicorn
author_rank: Newbie
timestamp: June 23, 2023, 04:26:08 pm
content: Hello there!I have a Supermicro PWS-706P-1R 750W server PSU, which is not working anymore.I've opened it up, checked for the empty cap and did a visual inspection.In no time I found the SOT-89-3 Package on where the magic smoke escaped.Now the hard part: with what replace that thing?I still could see the markings on it, it says DKQ and a letter with a half circle at the bottom, like o or 0.Searching throug google lead me nowhere, only some sketchy aliexpress or russian pages.Can someone of you identify that component? (or tell me with what to replace without immediately setting everything on fire)I've soldered leads to it to measure if it is necessary, but it's on the high voltage side, and I don't want to plug it in in that state untill necessary.Thanks in advance for your help!

author: ArdWar
author_rank: Frequent Contributor
timestamp: June 23, 2023, 04:51:08 pm
content: 2SC4672 maybe?There are a lot of SOT-89 components with DK* marking.

author: fzabkar
author_rank: Super Contributor
timestamp: June 23, 2023, 07:21:57 pm
content: https://www.aliexpress.com/w/wholesale-sot89-dk.html?initiative_id=

author: fatunicorn
author_rank: Newbie
timestamp: June 24, 2023, 11:31:32 am
content: Thank you two for the reply!It looks indeed, that the part is the 2SC4672.What's the worst thing that can happen, if I solder one of those in there?I will try to order some of them, and see if it will work.

author: wasedadoc
author_rank: Super Contributor
timestamp: June 24, 2023, 11:42:21 am
content: Quote from: fatunicorn on June 24, 2023, 11:31:32 amThere is a distinct possibility that the new one you fit will release its magic smoke. The real fault that caused the original to fail may still be present.

author: MathWizard
author_rank: Super Contributor
timestamp: June 25, 2023, 04:41:21 am
content: I'd map out some of the circuit, I use a magnifying loupe, or sometimes a LCD microscope. Sometimes it's like going off to another world.
Part number for Leader LBO-514 C.R.T.? - Page 1
Forum section: electronics / repair

author: CaptDon
author_rank: Super Contributor
timestamp: June 15, 2024, 08:57:40 pm
content: I am looking for an oscilloscope with a P7 long persistance phosphor. I found an LBO-514 on Ebay with an orange filter which suggests it may be a P7 version which was an option. I found the schematic on ElectroTanya but no part number for the C.R.T. It is a 14 pin looking at the schematic and I wonder what C.R.T. Leader used such as 5DEP7A or 5UP7A etc. Thanks for any leads!!

author: fzabkar
author_rank: Super Contributor
timestamp: June 16, 2024, 05:33:36 am
content: I had a look inside my LBO-514, but the CRT was covered in a black shroud. There were no visible markings. It would have involved a significant disassembly to go any further. Sorry.

author: CaptDon
author_rank: Super Contributor
timestamp: June 17, 2024, 12:11:07 am
content: Turns out the seller brickaudiophile is a totally unprofessional asshole!!
Looking for part number of a STmicro component on Exalos SLD driver board - Page 1
Forum section: electronics / repair

author: powlimited
author_rank: Newbie
timestamp: April 27, 2022, 08:53:33 pm
content: Hi all,I have a pricey Super Luminescent Diode driver board (EBD5000) that my fellow peer somehow decided it was a good idea to test the input voltage with no current limiting, long story short the board suffered 12V 3A when it was rated at 5V 3A max 0.5A nominal, and even possibly in reverse.The board is supposed to have ample input protection, so when I found that only the onboard 3A fuse was blown, I replaced it and hoped for the best.Unfortunately, the board still has a ~2Ohm short on the input, and only a portion of the power rails are present when tested with a current limited supply. The board also still wants to sink tons of current. After some troubleshooting (Finger test, probing around) I found this STmicro component is getting disturbingly hot and most of the voltage drop is across it. I highly suspect that this component has also failed too.It seems to be some kind of diode, I tried looking for an exact part number and found nothing on google, any help would be appropriated.The whole board with the suspected component pointed out is also attached if this helps, also I am open to any other suggestions of components that also might have failed.

author: fzabkar
author_rank: Super Contributor
timestamp: April 27, 2022, 09:19:15 pm
content: It's probably a 5V unidirectional TVS diode. If there are no other problems, the circuit should work without it.Depending on the size, it could be SMAJ, SMBJ, or SMCJ.https://www.st.com/resource/en/datasheet/smaj.pdfhttps://www.st.com/resource/en/datasheet/smbj.pdfhttps://www.st.com/resource/en/datasheet/smcj15a.pdf

author: fzabkar
author_rank: Super Contributor
timestamp: April 28, 2022, 01:14:54 am
content: It's actually an SM6T6V8A with a breakdown voltage of 6.8V. A 5V TVS diode (eg SMBJ5.0A) will have a standoff voltage of 5V and a breakdown voltage in excess of 6V.https://www.st.com/resource/en/datasheet/sm6t100a.pdf

author: powlimited
author_rank: Newbie
timestamp: April 28, 2022, 07:39:31 am
content: Thanks so much for the help and quick reply, I guess I' ll remove it for now and see what happens, the part is out of stock everywhere..

author: fzabkar
author_rank: Super Contributor
timestamp: April 28, 2022, 08:41:46 am
content: Any unidirectional 5V TVS diode can replace it. SMBJ5.0A would be suitable. I'm assuming that the supply voltage is tightly regulated at 5.0V.

author: powlimited
author_rank: Newbie
timestamp: April 28, 2022, 08:52:14 am
content: Yes, it is tightly regulated.Found this still in stock for me:P6SMB6.8A, I am assuming this should also work. Will keep this updated.
Part number identification - Page 1
Forum section: electronics / repair

author: pisoiu
author_rank: Regular Contributor
timestamp: December 04, 2019, 09:51:08 am
content: Hi,This is an ESC for a drone and I need to modify it a bit, as the voltage available is a bit higher than the max spec of this unit.But I can't figure who manufactures that part number on the right of the inductor. I didn't find it on smd codes catalogs either. It's marked T8BE. It is a buck converter, it outputs 12V and working freq is approx 1MHz.Does anyone recognizes it?Thanks.

author: fzabkar
author_rank: Super Contributor
timestamp: December 04, 2019, 01:53:04 pm
content: MPQ4560-AEC1, Monolithic Power, Industrial-Grade Step-Down Converter, 2A, up to 2MHz, 3.8V - 55V in, marking T8, QFN-10:https://www.monolithicpower.com/en/documentview/productdocument/index/version/2/document_type/Datasheet/lang/en/sku/MPQ4560-AEC1/
Part source MB90611A LQFP100 - Page 1
Forum section: electronics / repair

author: Cozzmo
author_rank: Regular Contributor
timestamp: January 03, 2020, 11:22:17 am
content: I am repairing a unit that is used to test vending machine coin mechanisms. A faulty coin mechanism was plugged in blowing up the transistors which seems to be kind of common. I have repaired several before. This time the transistors held together burned tracks on the board and the main CPU on the daughterboard let out a heap of smoke but no trace damage on the daughterboard.I repaired / removed the faults and the base board works with another CPU, but I need to replace the chip. I have tried 2 companies from google searching so far and both say they have stock until an order is placed then no stock. One seller on eBay lists for $120 each, which is out of the budget. AU$50 Max I’m willing to gamble on this.** Must be square LQFP package not rectangular QFP. ** any help appreciated.

author: MDBSolution
author_rank: Newbie
timestamp: May 31, 2021, 09:51:12 pm
content: Hi. Does your device communicate via serial MDB? If so I make MDB simulators and testers that you could use to test coin mechs., validators, etc. Contact me at info@mdbtools if interested.

author: amyk
author_rank: Super Contributor
timestamp: June 01, 2021, 12:13:25 am
content: That's a mask ROM MCU... and with what looks like no ROM identification marking, you are likely out of luck.

author: Pete66
author_rank: Regular Contributor
timestamp: June 01, 2021, 06:45:01 am
content: around $15 on Ali ExpressHe says he has 9,999 pieces available. No feedback you are taking a chance but that's all there isLink:https://www.aliexpress.com/item/4000062474414.html?spm=a2g0o.productlist.0.0.671f61c96PQkeo&algo_pvid=7c73e988-7db8-4112-beb9-1db3a9f4cbdc&algo_expid=7c73e988-7db8-4112-beb9-1db3a9f4cbdc-0&btsid=0bb0623116225297620888275ea0c4&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_
Part to replace - Page 1
Forum section: electronics / repair

author: sdancer75
author_rank: Frequent Contributor
timestamp: December 15, 2020, 06:04:09 pm
content: What is this part that seems burned? Resistor? It has about 280ohm of resistance but it doesn't look like resistor. Anyway I can confirm that pcb describes it as R2 which means that indeed it's a resistor. So it a special kind of resistor or just destroyed?

author: bob91343
author_rank: Super Contributor
timestamp: December 15, 2020, 06:34:48 pm
content: It could easily be a resistor, and even a good one. Sometimes oddball parts look like that and have no markings. While measuring its resistance, hold it in your hand while watching the meter to see if it's a thermistor. Reverse the leads to see if it's a diode.Why do you even care? Replace it with a 270 Ohm resistor and see if the unit works.
Partial Failure - Resistance Decrease Over Time with Power - Page 1
Forum section: electronics / repair

author: Rjc987
author_rank: Contributor
timestamp: October 30, 2023, 05:57:48 pm
content: Okay, so I’ve never seen this before and was hoping someone could help. I have a 250v 3A adjustable power and current supply (Schematic below) that suddenly will only put out ~150v at full. It starts out at about 170v and quickly drops to 160v in a few seconds then slowly to about 150v over a minute when powered on from cold. I probed the voltages and they all look correct before the LM317 - getting 350v + coming out of the transformer, etc but I noticed when I probe the pins on the wire wound pot (37k) controlling the LM317, it starts out around 22k and quickly drops to 21, 20, 19 … down to around 16-17k which I assume is the problem- the LM317 is seeing the pot as if it were set to ~half. I immediately suspected a cap in parallel increasing In resistance as it charges but I pulled all the caps and they’re all good. Since the voltage control is working fine just at half power I assume the LM317 and the BU406 are both good. Other than the caps and trannys there’s only a few diodes and resistors in the circuit so what am I missing here?The voltage section is circled in red and the pot is in green. Sorry for the bad quality schematic but it’s all I can find.

author: soldar
author_rank: Super Contributor
timestamp: October 31, 2023, 08:15:30 am
content: I cannot make sense of the diagram. It looks like the base of the transistor only goes to the capacitor. Maybe others can help.

author: fzabkar
author_rank: Super Contributor
timestamp: October 31, 2023, 04:15:02 pm
content: The base of the transistor appears to be connected to the junction of the zener diode and its series resistor. This will limit the voltage differential between the input and output of the regulator.That said, ISTM that the pass transistor will be dissipating a massive amount of power.
Parts diagram for Gardner-Denver wirewrap gun - Page 1
Forum section: electronics / repair

author: PaulAm
author_rank: Frequent Contributor
timestamp: March 19, 2021, 01:58:18 am
content: Hey guysI'm trying to track down a parts diagram for a Gardner-Denver 14B1 wirewrap gun. There's got to be a parts diagram out there somewhere. This is from maybe the 80s? I think that division was part of Cooper Industries at the time, but I'm not having a lot of luck trolling through the wayback machine to find anything.Anyone got any pointers? I did get a patent that is referenced on the gun, which is at least something, but it doesn't quite match the body. I have a buggered bearing and I need to be able to figure out how to get it apart without destroying it.thanksPaul

author: Stray Electron
author_rank: Super Contributor
timestamp: March 20, 2021, 01:34:53 pm
content: I've had brand new WW guns in the past and I have seen the parts lists, etc so I know that they did print them but that was about 40 years ago and I haven't seen one since. But I just wanted to say that used WW guns show up regularly on Ebay so it's probably easier to go buy another one than try to find parts.Six WW guns sold in one lot for $9.99 and $11 to ship.https://www.ebay.com/itm/Gardner-Denver-Wire-Wrap-Tool-lot-of-6/274686023597?hash=item3ff49017ad:g:HccAAOSwLLlgGH4G

author: PaulAm
author_rank: Frequent Contributor
timestamp: March 20, 2021, 03:38:17 pm
content: Yeah, that was a deal. I have a couple of those guns and they're really nice. The air lines alone were worth the bid.Just trying to keep stuff out of the landfill. It's not in my nature to junk a perfectly good tool for a 50 cent bearing.I did find another patent drawing that showed how the front is put together, which is probably enough. Waiting for a bearing to arrive now before tearing it apart.

author: PaulAm
author_rank: Frequent Contributor
timestamp: March 24, 2021, 01:21:40 am
content: Turned out to be fairly trivial. After pulling the brushes (a 2 second task that took an hour because the brush retainers were broken and/or stuck), the armature assembly just falls out of the back when the rear cap is unscrewed.Very nice engineering. Should be back to snuff with a couple of new bearings and some brush retainers. Going to have to fab those, but shouldn't be too tough.
Patton U2-1887 potential thermo fuse issue - Page 1
Forum section: electronics / repair

author: SEBern
author_rank: Newbie
timestamp: August 08, 2025, 12:37:37 am
content: I bought a NOS Patton U2-1887It was working all last summer went to turn it on this year got a hum, the lights dimmed and it stopped.I saw a previous thread about a thermo fuse but my issue is that I don’t want to start taking things apart and doing more damage. I have my original Patton, same model, from the 90’s and I think it had the same issue. Here’s hoping it’s something I can get a replacement part and fix, they are in my opinion the best shop fans.This is where I have stopped in my cleaning and taking apart process since I cannot visibly see the fuse.What am I looking for?Thank you

author: Poroit
author_rank: Frequent Contributor
timestamp: August 08, 2025, 05:30:55 am
content: G'day SEBern,That is probably the thermal fuse buried in the windings.(attached)

author: SEBern
author_rank: Newbie
timestamp: August 08, 2025, 12:09:26 pm
content: That’s what I figuredIt’s glassI’m guessing I have to clip the binding wire to get it out?

author: SEBern
author_rank: Newbie
timestamp: August 08, 2025, 07:56:15 pm
content: It was the thermal fuse, thank youBut I think the switch is shot too but that’s an easy part to getI’m going to try the same thing on my other one

author: Gyro
author_rank: Super Contributor
timestamp: August 08, 2025, 08:47:23 pm
content: Rather than a thermal fuse, that is a self-resetting thermal cutout (as indicated on the motor label - the smaller one). If it failed, it has probably tripped several times in the past. It would be worth investigating the underlying cause eg. stuck bearings at first turn on (if the lights dimmed), in which case they're probably in poor condition.P.S. While looking up what it is (a high velocity floor fan of others), I noticed several hits for dangerous cracking of the rotating hub. It's probably worth checking for cracks too.

author: SEBern
author_rank: Newbie
timestamp: August 09, 2025, 01:03:55 am
content: Definitely going to look into the stuck bearings.That would explain the labored start up for sureThank you
Pb with hp 16500b logic analyzer expansion card. - Page 1
Forum section: electronics / repair

author: willycat
author_rank: Newbie
timestamp: September 11, 2024, 04:33:13 pm
content: Hi,Yesterday, while using my logic analyser, a component suddenly burned on my hp16535 multi probes expansion card. The PCB is a little damage, but this is fixable. This component is a polarized tantalum capacitor. I think it is used for decoupling, but i am not sure. He is completely burned, so i can't see his reference or value. If someone has this board, can he give my his value ? He is referenced C66 on the board and near the flat ribbon connector.Thanks for your help.

author: philpem
author_rank: Frequent Contributor
timestamp: September 12, 2024, 12:09:08 pm
content: The 16500B can take a lot of different types of analyser card. You need to post the model number of the card so it can be identified - it should be on the metal backplate.Some 16500 series cards also work in the 16700 series analysers.If you can't identify it, then the value may be similar to other parts on the board. It obviously had a lot of current going through it, so it was probably on a power rail.

author: coromonadalix
author_rank: Super Contributor
timestamp: September 12, 2024, 02:13:38 pm
content: if it by miracle still works measure the voltage on both traces / pads or what is left it will at least give you a voltage valueand you could guess between 10 and 47 uf sure an picture of it will helpgood luck

author: MarkL
author_rank: Unknown
timestamp: September 12, 2024, 02:17:42 pm
content: The card type was in the post: HP 16535A multi-probe control module.It's a N-to-2 analog MUX for oscilloscope probing. It's a rare card, but hopefully someone has one and can look at the part value for you. I couldn't find any on-line photos with sufficient detail.The value of C66 is probably not too critical, and you could try to match it up by measuring the pad size or what's left of the body, and compare with the nearby C58 and C59 as philpem has suggested. Another approach would be to draw out the circuit around it to see if that presents any clues.It also looks like there might some additional damage in an inner layer near U24, but it's hard to tell from the photo if that's a burn or a copper void.You could also try posting to HP-Agilent-Keysight-Equipment on groups.io.

author: willycat
author_rank: Newbie
timestamp: September 14, 2024, 06:38:41 pm
content: Thank you for yours suggestions.I tested the board and good news, it is always completely functional. Damages are only in the top layer.I will post to the group you mentioned which appears to be dedicated to this material.Thanks for your help.

author: artag
author_rank: Super Contributor
timestamp: September 15, 2024, 12:13:09 pm
content: There is alsohttps://groups.io/g/logicanalyzers/messagesbut the group Markl mentioned has been active for much longer and probably has more chance of giving you an answer. The logic analyzers group does seem to have a strong Tek element though, which will be useful to some people.
PC Analyzer Card - Page 1
Forum section: electronics / repair

author: GGMM
author_rank: Frequent Contributor
timestamp: August 25, 2024, 07:15:50 pm
content: Hello,Does anyone have the electronic schematic of this PC card analyzer.As I said, it worked well, ...before the displays remained desperately off.See the picture for model of card (It’s an old picture , we could see the dashes, but now the displays are completely off), I couldn’t put the video because it is 25 MB. This is to show the PC Analyzer card model.Any other ideas are welcome for repair.cdt

author: GGMM
author_rank: Frequent Contributor
timestamp: August 25, 2024, 07:16:25 pm
content: the picture

author: GGMM
author_rank: Frequent Contributor
timestamp: August 25, 2024, 07:24:38 pm
content: Mp4 compressed, them Zipped

author: BlownUpCapacitor
author_rank: Frequent Contributor
timestamp: August 25, 2024, 07:53:31 pm
content: There don't appear to be too many components. If the PCB is only double-sided, it shouldn't be too difficult to reverse-engineer it and get a schematic.
PC CPU resistance. - Page 1
Forum section: electronics / repair

author: ktulu
author_rank: Regular Contributor
timestamp: November 01, 2024, 09:40:39 am
content: I have a Gigabyte GA-H61MA-D3V rev2.0 motherboard and an i5-3470 CPU. The board keeps restarting every few seconds. The CPU barely gets warm for that short period of time. (pulsating)However the board work fine with a G530 CPU. It has the latest BIOS flashed. F7cI've measured the tiny caps on the underside of both CPU's.The i5 measures very low, 0.8-1 Ohms while the other I get around 30 Ohms.I need some help if somebody still has this CPU (i5-3470) and could take some resistance measurements.I am very curious if these very low readings are normal or the CPU is demaged.Thank you.

author: wraper
author_rank: Unknown
timestamp: November 01, 2024, 10:20:40 am
content: There is small chance resistance might be normal, although I'd expect resistance this low from something more modern. You really need a measurement of CPU based on the same die to be sure.QuoteBTW does this measurement include multimeter lead resistance or not? If it includes something like 0.4 ohm with leads shorted without measurement nulling/subtraction, then it's nearly certainly fried.

author: ktulu
author_rank: Regular Contributor
timestamp: November 01, 2024, 10:40:15 am
content: Without leads resistance. Btw this is measured on VCC, but VCCAXG is also a few Ohms.According to this:https://www.gadget-manual.com/pinout-cpu/

author: ktulu
author_rank: Regular Contributor
timestamp: November 02, 2024, 07:35:48 am
content: What voltage is on VCC?I tried with 1V, but at 1A no capacitor gets hot. Without a thermal camera it is hopless. I thought maybe I get lucky and only a cap is partially shorted.
PC front panel 3.5mm jack socket replacement  - Page 1
Forum section: electronics / repair

author: Erling
author_rank: Newbie
timestamp: October 28, 2020, 02:04:27 am
content: I have Zalman Z3 case and Gigabyte HD3P motherboad (HD Audio supported). Front audio panel has 2 separate 3.5mm TRS jacks, one for headphones and another for a microphone. I'd been using front panel with zero problems for several years, but recently my Realtek HD started to report random disconnections: sometimes mic disconnects, sometimes so do headphones. Usually they "re-plug" automatically, but interruption bothers me anyway, so I decided to replace 3.5mm jack sockets in order to avoid random contact failure. Headphones and mic are definitely not the source of the problem since they work perfectly with other PCs.I easily opened the case, took out the front panel PCB and desoldered both jack sockets. They look pretty normal, like this:https://i.ibb.co/2qFf4VL/3-5mm-Audio-Socket-Phone-Jack-3-5mm-Headphone-Jack-Types-Pj-3f07.jpgWhat I didn't know is that they have 5 pins instead of 3. I've already read some manuals (likehere,hereandhere), so now I understand how detection works. But I have one concern. Most circuit schematics for 3.5mm jacks with detection pins specify that detection pins and respective signal pins are normally shorted/closed (NC). But the sockets I'd desoldered are quite the opposite: looks like detection pins and respective signal pins are normally opened/disconnected. I lurked through the web more and found numerous mentions of a following statement:"NC 3.5mm jack sockets are used for AC97 standard, NO 3.5jack are used for HD Audio standard". This is quite confusing since I can barely find a vendor who would advertise 3.5mm sockets as NO. Almost all available sockets seem to be NC.My questions are:1. Is it true that HD Audio front panel requires 3.5mm jack sockets with normally opened detections pins?2. If yes, can I rebuild/rewire/hack NC sockets (or HD Audio front panel) so that they will work with HD Audio properly?

author: coromonadalix
author_rank: Super Contributor
timestamp: October 28, 2020, 02:44:46 am
content: https://www.sevenforums.com/sound-audio/44491-ac97-hd-audio-front-panel-layouts.html

author: ambrosia heart
author_rank: Regular Contributor
timestamp: October 28, 2020, 02:45:49 am
content: Too lengthy,no time to read your composition.Replace it if you want.Buy at taobao if you want.https://s.taobao.com/search?q=3.5mm%E6%8F%92%E5%BA%A7%E8%80%B3%E6%9C%BA%E6%AF%8D%E6%8F%92%E5%BA%A75%E8%84%9A&imgfile=&js=1&stats_click=search_radio_all%3A1&initiative_id=staobaoz_20201028&ie=utf8https://detail.tmall.com/item.htm?id=596018247107&ali_refid=a3_430620_1006:1110788254:N:d5+Ndo/EXcKLUiRdUwqguw==:e6f1da1e1c2eccabd9332d16b3b8a193&ali_trackid=1_e6f1da1e1c2eccabd9332d16b3b8a193&spm=a230r.1.14.1
PC motherboard: CLK signal amplitude 250mV - Page 1
Forum section: electronics / repair

author: ankeakala
author_rank: Contributor
timestamp: December 01, 2020, 03:20:43 pm
content: Any common, known issues that could cause such? Frequency is correct, it's just that the signal amplitude is presumably way out of range, and shifted to higher voltage level.

author: ankeakala
author_rank: Contributor
timestamp: December 01, 2020, 03:36:50 pm
content: And after probing a working motherboard, this seems to be perfectly normal. Who would've known.

author: shakalnokturn
author_rank: Super Contributor
timestamp: December 01, 2020, 03:41:10 pm
content: How's the probing done?Is this a differential clock line?It may well be normal, have you checked the datasheet for whatever you're probing (PLL output)?

author: StillTrying
author_rank: Super Contributor
timestamp: December 01, 2020, 03:51:37 pm
content: It looks like you're probing 46Mhz with the scope probe on X1 and the scope's 20MHz BW limit on.X10 and the 20MHz BW off would give a muchcloseramplitude value.

author: ankeakala
author_rank: Contributor
timestamp: December 02, 2020, 08:01:15 am
content: Quote from: StillTrying on December 01, 2020, 03:51:37 pmA X10 probe has the effect of reducing capacitance by a factor of ten.OK now it makes senseLooks somewhat closer to the expected values
PC motherboard help - Page 1
Forum section: electronics / repair

author: DiGiTAL S80
author_rank: Newbie
timestamp: October 03, 2021, 03:16:20 am
content: Helloi am trying to fix an old motherboard that does not boot due to bulged capacitors, those capacitors are on top of the cpu socket, so i decided to remove those capacitors and then buy new ones, before removing the capacitors, i tested them using the continuity mode on the multi-meter and there was no short, after i removed those 5 capacitors the board is shorted to ground not only on the spots where the capacitors were, but also on other spots, is this normal or did i destroy the motherboard?

author: amyk
author_rank: Super Contributor
timestamp: October 03, 2021, 04:47:42 am
content: Are you sure you put the multimeter probes the same way around both times?There are plenty of (normally reverse-biased) diode junctions across the power rails and if your multimeter's test voltage is higher than their Vf, they can conduct.
PC motherboard USB 5v circuit fried  - Page 1
Forum section: electronics / repair

author: ChronosHD
author_rank: Newbie
timestamp: December 12, 2022, 05:47:19 pm
content: Hi Community,I have unfortunately fried the 5v circuit of my motherboard and when I troubleshooted, I figured USBs work but don't get power, as using an external powered hub awakes them.I'm comfortable with fixing electronics, but I'm clueless what component to check and replace. I've checked fuses for USB and they show 0 resisrence, I guess that's good.Can somebody guide me please?The motherboard is an Asus H110 Intel, from a Asus g11cd desktop.Much appreciated in advance!

author: Hamelec
author_rank: Regular Contributor
timestamp: December 12, 2022, 07:06:57 pm
content: is the via hole burned?

author: ChronosHD
author_rank: Newbie
timestamp: December 12, 2022, 08:11:11 pm
content: I don't think so, see zoom in photo attached.

author: coromonadalix
author_rank: Super Contributor
timestamp: December 12, 2022, 08:14:54 pm
content: the black p 260 written on it smd part near a capacitor 1st photo should be a fuse or a poly fuse / at least seems like a fuseCheck its continuityCan you dust off over the 2 black ic's near the usb sockets, cant read themthks

author: ChronosHD
author_rank: Newbie
timestamp: December 12, 2022, 08:55:42 pm
content: 136 bbUJG, is that what you ask for?P260 conducts clean.

author: mariush
author_rank: Super Contributor
timestamp: December 12, 2022, 10:12:14 pm
content: those bbUJG parts could be ESD protection chips

author: ChronosHD
author_rank: Newbie
timestamp: December 13, 2022, 05:35:59 am
content: How do I know if that's the problem, checking conductivity?

author: ChronosHD
author_rank: Newbie
timestamp: December 13, 2022, 09:38:26 pm
content: Bump

author: fzabkar
author_rank: Super Contributor
timestamp: December 13, 2022, 09:56:44 pm
content: Those ESD protection parts contain TVS diodes. Check whether any of the USB pins (other than Ground) are shorted to ground.Measure the voltage on either side of the polyfuse. If +5V is not present, then locate the source of the Vbus supply by performing a continuity test between the polyfuse and the various DC-DC converters. Upload a detailed photo of the motherboard if you need help with this.
PC motherboard voltage regulator MOSFET driver replacement - Page 1
Forum section: electronics / repair

author: Phaseseeker
author_rank: Regular Contributor
timestamp: November 21, 2022, 06:18:13 pm
content: I'm trying to fix a PC motherboard where the driver for one of the VCORE regulator MOSFET drivers, an UP1952P by UBIQ Semiconductor (never heard of them either) got shorted and killed by the CPU cooler bracket. My problem is that I can only get said part from China with either a month of wait or an outrageous shipping cost, so I thought about replacing it with another driver I can get from western sources; I'm not sure how to pick an appropriate device though, I tried looking on mouser but I didn't find anything that looked like it would work.I've also thought about just making the whole regulator work in 3-phase mode (it's got four identical converters in parallel, and the CPU that is installed shouldn't need the full power the regulator is capable of) by removing the driver + corresponding inductor (the MOSFET themselves are fine) and configuring the controller (UP1651, also by UBIQ) for 3-phase mode but in my tests it doesn't seem happy about it and fails to start. Is there something I'm missing there or could it just be a matter of the CPU drawing too much and dragging the output down?Thanks in advance for any replies.

author: fzabkar
author_rank: Super Contributor
timestamp: November 21, 2022, 07:27:01 pm
content: The datasheet for the UP1952 identifies Unitpower as the manufacturer, not UBIQ Semiconductor. Are they the same company?http://img.plokij.com/UserDocument/2017y/WGGKLTD/dn/zl10935.pdf

author: mariush
author_rank: Super Contributor
timestamp: November 21, 2022, 08:27:28 pm
content: It's UPI Semi , and Ubiq is part of UPI Semi nowadays... they merged in 2019.Anyway... as you figured out it's a mosfet driver.Do some research and see if Richtek RT9624 would be compatible ... the pinout is the same but I didn't check the specs :https://www.richtek.com/assets/product_file/RT9624B/DS9624B-07.pdfThough it seems to be WDFN 3x3 while the UP part is WDFN 2x2 ... this version RT9624GGQWA is not in stock but it's 8-WDFN-SL (2x2) :https://www.digikey.com/en/products/detail/richtek-usa-inc/RT9624GGQWA/16376826

author: Phaseseeker
author_rank: Regular Contributor
timestamp: November 22, 2022, 08:32:38 pm
content: Thanks for the suggestion, it looks like that part would be compatible; Unfortunately, it's about as hard to get as the original here in Europe (at least in the right package - the motherboard uses the "SOP-8 with exposed pad" version). Looks like I'll have to get it from China and wait a month after all.
PCB conformal coating - Page 1
Forum section: electronics / repair

author: gobo207
author_rank: Contributor
timestamp: January 30, 2020, 12:42:19 pm
content: Hi All,I recently repaired a PCB from an air conditioning unit compressor. Some of the tracks had blown and an arc made its way across a good 8mm gap burning the fiberglass.My question is, once I ground all the carbonized fiberglass away and strengthened the leftover track with de-solder wick and solder, do I need to put a conformal coat back on? And if so, what should I use?Thanks,

author: aqibi2000
author_rank: Regular Contributor
timestamp: January 30, 2020, 01:06:52 pm
content: PCB Lacquer

author: Zucca
author_rank: Unknown
timestamp: January 30, 2020, 01:42:04 pm
content: to fill up the hole epoxy should be fine, I think.To repair solder maskcheap, nail polish transparentPro choice, UV PCB lackhttps://www.amazon.com/Curable-Solder-Repairing-Paint-Green/dp/B01MUB4PJL

author: Silverbackaircon
author_rank: Newbie
timestamp: May 25, 2020, 02:08:26 pm
content: PCB laquer is the better choice in my opinion.Fyi we do Aircon PCB repair andAircon Gas top up
PCB Corrosion? What can i do? - Page 1
Forum section: electronics / repair

author: jimmyc_
author_rank: Contributor
timestamp: August 25, 2021, 02:14:01 pm
content: Hello people!I have a non-working Mac Pro 2010 Logic board which i want to fix. I have no idea where to begin and there's no schematics available on the web.I started by poking around the power connectors and saw this. Strange to see corrosion on this portion of the PCB logic board. Do i clean this with IPA?

author: fcb
author_rank: Super Contributor
timestamp: August 25, 2021, 02:24:20 pm
content: Not wishing to teach you to suck eggs - have you checked Louis Rossman's channel on YT?

author: Manul
author_rank: Super Contributor
timestamp: August 25, 2021, 02:44:30 pm
content: Just to make sure, what area in the picture you are talking about? Around through-hole connector pins? Is it not flux residue?

author: ataradov
author_rank: Super Contributor
timestamp: August 25, 2021, 03:58:06 pm
content: Yes, what is shown on the picture is not corrosion, it is just flux from the connector soldering. You can clean it, but it is not harmful, and is not the source of any problems.

author: jpanhalt
author_rank: Super Contributor
timestamp: August 25, 2021, 04:36:52 pm
content: Try cleaning first. If that doesn't work, consider a type of creep corrosion.This from Dell might help:https://www.dfrsolutions.com/hubfs/DfR_Solutions_Website/Resources-Archived/Publications/2005-2007/2007_08_creep_corrosion_on_lead-free_pcb_in_high_sulfur_environments.pdfThe photo is not sharp enough to see reflections from solder flux v. corrosion. On the most affected connector, it looks like the artifact may be burrowing under the solder mask. That is a creeping corrosion. There are different types.

author: jimmyc_
author_rank: Contributor
timestamp: August 26, 2021, 02:57:44 am
content: Quote from: Manul on August 25, 2021, 02:44:30 pmThe pins are soldered to the PSU connector. I had problems with the Logic Board starting up, so looked at this area. I'm not sure if that's flux residue or corrosion - The board came as is.

author: jimmyc_
author_rank: Contributor
timestamp: August 26, 2021, 03:02:51 am
content: Quote from: jpanhalt on August 25, 2021, 04:36:52 pmThanks for this share! I'll try cleaning with IPA then get back on this!
PCB fault diagnosis video? - Page 1
Forum section: electronics / repair

author: Clarmrrsn
author_rank: Contributor
timestamp: November 30, 2019, 03:15:11 pm
content: I am a new member and loving the content of this forum, how I did not find this years ago I will never know, a wealth of information and knowledge.Anyway, my question...While watching one of Daves videos I seem to remember he mentioned that he had a made a video on diagnosing/tracing PCB faults (Using an OScope?)I have been hunting to try and find it and beginning to wonder if I actually did hear that (maybe a few too many beers last night)This is a skill I would very much like to explore.Was this part of a lucid hallucination or does it indeed exist?
PCB microscope - Page 1
Forum section: electronics / repair

author: chris_withall@yahoo.com
author_rank: Newbie
timestamp: March 11, 2024, 01:41:46 pm
content: Can anyone tell me if the Andonstar AD106S USB Digital Microscope is any good for doing PCB soldering repairs? If not what would the forum experts suggest?My eyes are getting old, i don't do a lot of PCB soldering, so this would only be for occasional use. Hence i don't want to spend too much on a Digital Microscope.Thanks Chris