hybridfree/eevblog-posts huggingface dataset:
(SOLVED) Help with a Sonance DSP2-150 power supply schematic - Page 1
Forum section: electronics / repair

author: rfengg
author_rank: Regular Contributor
timestamp: December 08, 2024, 04:02:51 pm
content: Hi All,Need your help with the schematics / service manual for a dead Sonance DSP2-150.Think the SMPS is dead as I can get no voltages on any of the output rails.Attached is a pic of the amp.....the SMPS board is just marked as "2-150 PSU board".All the semicons test fine and I cannot find any shorted caps either.

author: rfengg
author_rank: Regular Contributor
timestamp: December 13, 2024, 03:11:46 pm
content: After a bit of poking around, was finally able to get the amp working.Initially tried to contact Sonance tech support and they were no help at all with the service manual or the schematics.....so had to go down the harder route......tracing all the SMPS circuitry by hand.For the benefit of others.....here's what I found.When I got the unit, there was absolutely no signs of life.....when the PS board was disconnected and isolated from all other assemblies, I got only the +5V rail (initially I got this measurement wrong) and didn't realize that at that time the control signals to switch on the main relay on the PS board was fed from another assembly.......found this only after a hour of poking around.However, when the PS was connected to the control boardand even though the +HV supply for the amps were isolated,the 5V dropped to 1.8Vwhich made me suspect the caps on the PSU board.Sure enuf.....some of the rotten cheapo caps on the PSU had really bad ESR.......replaced the caps encircled on the pic attached and the 5V was no longer dropping to 1.8V and the amp started singing again...
Help with Benq MP720p repair. - Page 1
Forum section: electronics / repair

author: ghorizo
author_rank: Contributor
timestamp: February 10, 2020, 04:11:03 pm
content: Hello! Taking another stab at trying to fix this projector on which I already replaced a couple of capacitors a while back.Now the unit powers on but will only display black and white pixelated "static". It changes patterns a bit every reboot.Anyone have any idea what could be the cause of the problem?

author: Haenk
author_rank: Super Contributor
timestamp: February 10, 2020, 05:15:54 pm
content: Looks like you need to obtain and install a new mirror chip (DLP chip). This one is gone forever, probably due to overheating.Disassemble until you uncover the chip - the failure should be visible.Is the repair worth it? Not sure about that...

author: ghorizo
author_rank: Contributor
timestamp: February 10, 2020, 06:15:33 pm
content: Sorry to question you but aren't DLP chip failures static? The pattern here is changing more or less every reboot.The OSD menu is not working and neither any settings.
Help with chassis connector - Page 1
Forum section: electronics / repair

author: 4cx10000
author_rank: Regular Contributor
timestamp: November 04, 2019, 09:17:21 pm
content: Hello!Having problem finding a 18 pin female chassis connector from a wheel loader relay board. Anyone know where to find one?Thanks in advance!

author: 4cx10000
author_rank: Regular Contributor
timestamp: November 05, 2019, 08:24:25 am
content: Found it!In the cable connector I found Burndy, but ended up at Souriao and Mouser stock them.https://www.souriau.com/en-en/sms-series-quick-mating-plastic-rectangular-connector/straight-boardmount-short-pcb-female-3

author: ender4171
author_rank: Contributor
timestamp: November 05, 2019, 05:15:21 pm
content: Good on you for taking the time to come back and post the solution!
Help with cross ref diode - Page 1
Forum section: electronics / repair

author: zz28zz
author_rank: Regular Contributor
timestamp: August 09, 2019, 11:29:49 pm
content: Trying to order more parts for my car audio amp repair. Need a diode. Orig part# is HZS16L -1.Found specs on the EIC Semiconductor site but as usual, the type of factory specs provided aren't the same as what Digikey provides.EIC specs Dynamic resistance as 80 ohms at 0.5mA. Digikey specs Impedence (max) and I don't see anything with 80 ohms. Are these 2 parameters the same thing?Thx!

author: fzabkar
author_rank: Super Contributor
timestamp: August 10, 2019, 08:27:14 am
content: Usually the Zener's voltage and wattage are the only parameters that matter. Being 16V, it sounds like your Zener may be providing overvoltage protection.

author: zz28zz
author_rank: Regular Contributor
timestamp: August 10, 2019, 05:44:32 pm
content: The suffix of "1" indicates the reverse breakdown voltage is 15.6V +/-0.3V. It's used to control the -15V by controlling the base of a bi-polar transistor that steps -45V down to -15V. The -15V is used to power various op-amps in the audio section.Wattage is not spec'ed on the EIC site. That's why I'm trying to use dynamic resistance to find a replacement but need to know if the"Dynamic resistance at 80 ohms at 0.5mA" is the same thing as "Impedence (max)".

author: fzabkar
author_rank: Super Contributor
timestamp: August 10, 2019, 10:41:28 pm
content: I would think that those two parameters are describing the same thing. Essentially it is a measure of how much the Zener voltage varies with current. Ideally the dynamic impedance (dV/dI) should be 0.However, your application is not critical. The 56 ohm 0.5W series resistor in the collector circuit of the pass transistor would be rated for approximately 100mA ( Power = I x I x 56 = 0.5). This means that the base current (which flows through the Zener) would be around 1mA, assuming a hfe of 100. That's only 16mW. Therefore a low wattage Zener should suffice.

author: zz28zz
author_rank: Regular Contributor
timestamp: August 12, 2019, 05:25:31 am
content: No luck with Digikey for thru-hole 15.6V zeners.Found this one at Mouser:https://www.mouser.comProductDetail/Nexperia/BZV85-C15133?qs=sGAEpiMZZMtQ8nqTKtFS%2FISyHb0gtGyWBnoQo%2F6Jejk%3DIn the description it says 14.7V, but under Vz it says 15.6V which what I need. Sent them an email to verify if the 14.7V is a misprint.

author: fzabkar
author_rank: Super Contributor
timestamp: August 12, 2019, 06:48:14 am
content: "C15" implies 15V. Also, a lower wattage Zener (eg 400mW) would have a lower impedance at 0.5mA than a 1.3W type.Oops, I just realised that most of the Zener current would be flowing via the 4.7K resistor. That means the current would be 5mA or thereabouts.

author: zz28zz
author_rank: Regular Contributor
timestamp: August 13, 2019, 09:31:08 pm
content: The Mouser part is the only one I've found readily available. It's a 1.3W but I think it will work. I was a little concerned abt the +15 being different but I could always replace both diodes (for -15V and +15V). Any issues with that approach?
Help with diode identification  - Page 1
Forum section: electronics / repair

author: Martinr
author_rank: Newbie
timestamp: September 18, 2022, 10:40:50 am
content: A diode has failed on a Panasonic microwave circuit board. I believe the diode is part of the mains rectification section. I can’t find a schematic for this model.There are only 4 characters on the diode: zero, 6 and then two characters on their sides, which could be sixes or nines.I have copied these characters onto paper as they appear and also show 2 photos of the diode.I’d be grateful for any help in identifying it or a suggestion for a replacement.

author: m k
author_rank: Super Contributor
timestamp: September 28, 2022, 03:54:55 pm
content: Put a new one that is enough.Numbers could be 0.6*1000V 6A, 9A peak.

author: fzabkar
author_rank: Super Contributor
timestamp: September 28, 2022, 10:14:21 pm
content: I would locate a service manual for a similar Panasonic microwave oven and then identify a diode with the same function.Plenty here:https://elektrotanya.com/showresult?what=Panasonic+microwave&kategoria=All&kat2=All
Help with diode identification - Page 1
Forum section: electronics / repair

author: Siva-Na-Gig
author_rank: Newbie
timestamp: August 01, 2022, 09:00:29 pm
content: Hey everyone!I'm working on an old car battery charger, Craftsman 6v/12v model. One of the diodes blew...at least I think it's a diode. 2 leg, cylindrical body, black color with a polarization band on one end, coming off the transformer to a metal plate. The "good" one out of the two (wasn't blown in half) had these numbers on the body:S102528005In that order. I imagine these are super obsolete since google is turning up zero, any idea on where to start or what part would be an adequate substitute?Thanks!

author: fzabkar
author_rank: Super Contributor
timestamp: August 01, 2022, 10:30:22 pm
content: Could "8005" be a YYWW date code, ie week 05 of 1980?What are the dimensions of the diodes?What is the rated output of the charger?

author: Siva-Na-Gig
author_rank: Newbie
timestamp: August 01, 2022, 11:10:43 pm
content: Information on the face of the charger says:Sears 6 AmpInput 115W. 60Hz. 120 VAC. Output D.C. 6/12v. 6/6A.Dimensions of the diode are 0.371" long, 0.196" wide

author: BrokenYugo
author_rank: Super Contributor
timestamp: August 01, 2022, 11:16:45 pm
content: A picture is worth a thousand words, good pics of the diode and good pics of the area it came from is the fastest way to get this solved. Sounds like a center tap half wave rectifier deal running at 60Hz where anything with enough voltage and current rating will do, but it's easier to say that confidently if things can be looked at.

author: abdulbadii
author_rank: Frequent Contributor
timestamp: August 01, 2022, 11:48:22 pm
content: if lazy Reve. Engineering, simply get close to ithttps://www.futurlec.com/Diodes/6A04pr.shtml
Help with ESD Input Protection (LCR-1703, Appa 703, Cryustek ES51920) - Page 1
Forum section: electronics / repair

author: soho
author_rank: Newbie
timestamp: December 03, 2020, 09:25:30 am
content: Hello friends,currently I am trying to repair a ISO-Tech LCR-1703 (aka Appa 703) which obviously got damaged by some over-voltage at the inputs. After my repair attempt the main chip ES51920 seems to work again, but short-calibration of the meter still fails. There is still one faulty component to be replaced and these are the (shorted) SMD parts labeled ESD3 - ESD5 (see red frame in picture). I suspect that these are ESD varistors, but I can't get the correct specs (as they are all shorted). Could anyone help me with these?Thanks!

author: fzabkar
author_rank: Super Contributor
timestamp: December 03, 2020, 11:09:38 pm
content: They could be low capacitance ESD protection diodes. If you remove them, I expect that the device will work without them.I couldn't find anything in the datasheet ...http://www.cyrustek.com.tw/spec/ES51920.pdf... but I looked at some other Cyrustek chipsets ...http://www.cyrustek.com.tw/product-1.htm... and found an application circuit in this one:http://www.cyrustek.com.tw/spec/ES168.pdfUnfortunately there were no ESD protection devices. However, if you keep looking, you may find an example.Edit:Is there an ESD1 and ESD2? If so, see if they test like zeners.

author: soho
author_rank: Newbie
timestamp: December 04, 2020, 08:01:21 am
content: Hi fzabkar,thank you very much for your reply!Quote from: fzabkar on December 03, 2020, 11:09:38 pmYes this was my guess, too, but they could also be some MOVs (TVS or ESD). I de-soldered them and soldered three micro dip-switches on the board. When I open all three switches the open-calibration passes and when I close them all the short-calibration passes, too (having the shorting bar installed of course). All other dip-switch settings give a fail in calibration. Unfortunately the meter still jumps around some weird values, even after successful calibration. What is also interesting is that if I close all switches and test a small cap the meter shows an overload and if I open all three switches having the cap still installed the meter shows the correct value of the cap (without jumping around)!Quote from: fzabkar on December 03, 2020, 11:09:38 pmMe either. I checked all the public Cyrustek documents. But the helpful stuff (e.g. pinouts, schematics, chip internals ...) seem to be top secret for this particular chip. I had great hope in this post by HydrawerkQuote from: Hydrawerk on March 03, 2013, 07:18:30 pm... but the link is dead (and Google Plus is, too). The original schematics of the meter would have been most helpful.Quote from: fzabkar on December 03, 2020, 11:09:38 pmGood idea, but they seemed to have seen the magic smoke, too (they protected the USB port). All of them behave like 0 Ohm resistors. No capacitance, no inductance, no resistance whatsoever. Really strange ...Thanks again for your help!
Help with Fluke 415B HV PSU - Page 1
Forum section: electronics / repair

author: PartialDischarge
author_rank: Super Contributor
timestamp: June 07, 2022, 10:12:52 am
content: Anyone who has this PSU could send me a picture of the inside of it?I bought one and it has a broken selector so I'm not sure in what position it should be:

author: m k
author_rank: Super Contributor
timestamp: June 13, 2022, 10:17:44 am
content: Seems to be clear enough.Original page is in Japan but can't open it, 403.

author: strawberry
author_rank: Super Contributor
timestamp: June 13, 2022, 11:17:55 am
content: dont use sandpaper or something to clean contacts, it will destroy silver plating

author: PartialDischarge
author_rank: Super Contributor
timestamp: June 13, 2022, 12:01:55 pm
content: It is already working, found the schematics + the transformer outputs were actually marked on the side of the transformer.

author: coromonadalix
author_rank: Super Contributor
timestamp: June 13, 2022, 02:30:20 pm
content: your relays blades near the tube seems to be bent?

author: PartialDischarge
author_rank: Super Contributor
timestamp: June 13, 2022, 02:37:59 pm
content: Yes, I bought this one online and it had a number of issues, mostly mechanical. Someone bent those, and those relays actually switch the secondary HV.
Help with Fluke 434 3-phase power quality analyzer that gone dark - Page 1
Forum section: electronics / repair

author: Guy Holt
author_rank: Newbie
timestamp: February 04, 2021, 11:09:54 pm
content: The screen has gone dark on my Fluke 434 3-phase power quality analyzer. The backlight control won't make it any brighter. I know it is not a fuse because I can hear the meter power up. Any ideas what the problem or how I might be able to fix it myself.

author: simingx
author_rank: Contributor
timestamp: January 23, 2025, 01:36:12 pm
content: Not sure if you've solved this, but I changed all the little SMD electrolytics on my 434 and it solved the screen darkening issue. Hope this helps!
Help with graphics card repair - Page 1
Forum section: electronics / repair

author: Dar
author_rank: Newbie
timestamp: March 24, 2021, 04:12:11 pm
content: My Asus R9 290X had malfunctioned during routine gaming.After taking it to official repair services they they said that couldn't repair it.After disassembly I found what appears to be a few blown voltage regulators,and the other side of the pcb looks fine.Picture included below.Could it be fixed?Update:I have taken it apart again and took some more photos.https://photos.app.goo.gl/Jc1mDHRTW8CrD3WE6

author: Dar
author_rank: Newbie
timestamp: March 24, 2021, 04:20:46 pm
content: I'm sorry if the picture isn't clear enough.I only have this picture from when I took it apart.I am currently not at liberty to disassemble it again.

author: daisizhou
author_rank: Super Contributor
timestamp: March 25, 2021, 01:35:55 am
content: First, you need to clean up the interface,Measuring electronics,I suspect more components are damaged,There may be circuit schematics on the network,I suggest you search according to the line signal

author: Rasz
author_rank: Super Contributor
timestamp: March 25, 2021, 10:38:13 am
content: Quote from: Dar on March 24, 2021, 04:20:46 pmare you planning to repair it with telekinesis?

author: Dar
author_rank: Newbie
timestamp: March 25, 2021, 01:21:14 pm
content: I posted this in the middle of the night so I didn't have time then.

author: isopropilick
author_rank: Contributor
timestamp: March 27, 2021, 03:25:57 pm
content: I suggest you take some photos, then, clean the area with isopropyl alcohol or acetone, and remove the remainder of what appears to be a capacitor, perhaps eliminating the damaged component in its entirety you can solve the problem, otherwise you would have to see and repair the PCB damage.I suspect that the issue was a multilayer ceramic cap that shorted out.Good luck.
Help with hall effect sensors for a Milwaukee impact driver - Page 1
Forum section: electronics / repair

author: electrodeexx
author_rank: Newbie
timestamp: July 06, 2025, 10:07:07 am
content: Hi. I have recently got a hold of a milwuakee 2nd gen 3/8" m12 stubby impact wrench and have found it stopped working beacuse the hall effect sensors had been damaged by the rotor they had been rubbing against it. Before changing them the motor would only make a light movement. after replacing with similar ones from another brushless impact driver not of the same type the drill runs in reverse meaning when you put it in forward the motor turns backwards and vice-versa also after a short while the windings get really hot and the device goes into shut down mode.I have taken a picture of the hall sensors and I was hoping if someone could shine a light on weather these hall sensors are directional and need to be changed arround or are they the completely wrong ones since they are from a similar tool and not an exact replacement The tool i took them out of also had the same STEP written on it. the lettering on the original sensors is of no help they have STEP written on them to.Thanks.

author: Swake
author_rank: Frequent Contributor
timestamp: July 06, 2025, 07:05:41 pm
content: Yes, hall effect sensors have a direction.That board was made in December '23, so the drill is still under warranty.R1 looks cooked. R3 doesn't look very good either. There is a strange smudge on the left side of H1 and H3. The red part in the centre of the PCB is misaligned, might be because of the dismantlement.

author: mikerj
author_rank: Super Contributor
timestamp: July 06, 2025, 07:50:44 pm
content: Hall sensors are polarity sensitive, but if they have the exact same marking as the originals that shouldn't be a problem. It may just be the photo, but the field winding at the one o'clock position has some dark looking areas, is there any evidence of burnt wire here?

author: electrodeexx
author_rank: Newbie
timestamp: July 06, 2025, 09:40:41 pm
content: Thanks for the replys.Warranty will probably be void since this was purchased faulty from another seller.The misalignment in the casing is due to me disassembling the drill and not putting it back together yet fully. That dark area in the one o'clock winding is just due to shadows and i have checked all windings resistances they are ok. The smudged under the hall effect sensors is a glue adhesive milwaukee uses on these high impact tools. The r1 and r3 resistors measure 10kohms and seem to be ok.Since the sensors have polarity it might just be that i need to find another set and the ones i have used here are not compatible. I have recently learnt you can get different hall sensor types like latching and unipolar and bipolar.I thought these would work since they had the same markings "STEP" written on them and they were from a similar tool but mabey its just not right.
Help with Hickok 539B line meter - Page 1
Forum section: electronics / repair

author: Bargainhunter
author_rank: Regular Contributor
timestamp: January 27, 2021, 10:26:26 pm
content: I have a Hickok 539B tube tester with a line meter that "sticks". The needle will go up to about 90volts and then stick. It will release by tapping the meter with my finger. I have taken out the meter but the meter is sealed. The cover looks like it crimped over the body of the meter housing. The meter is made by Cleve for Hickok. Before I butcher up the meter, has anyone had success with opening a sealed panel meter?Attached is photos of the meter.Thanks in advance for your help.

author: Bargainhunter
author_rank: Regular Contributor
timestamp: January 27, 2021, 10:27:22 pm
content: Here is a photo of the front of the line meter.

author: Bargainhunter
author_rank: Regular Contributor
timestamp: January 29, 2021, 08:19:25 pm
content: Anybody ever opened "sealed" panel meters?
help with HP 41800 probe - Page 1
Forum section: electronics / repair

author: WB8PFZ
author_rank: Regular Contributor
timestamp: March 28, 2020, 03:23:16 pm
content: I received my Ebay probe yesterday. It works and is in nice condition except for the tip. By my measurements it is 1/8 inch short of making contact with the adapters. There was a small piece of broken plastic on the front tip that I removed. Can someone explain what I am missing? If I take the plastic sleeves off the adapters it will make contact. Chances are HP no longer has parts for these? Thanks Mike

author: JKKDev
author_rank: Regular Contributor
timestamp: March 29, 2020, 08:56:45 am
content: Check page 6-2 ofthisdocument.

author: WB8PFZ
author_rank: Regular Contributor
timestamp: March 29, 2020, 02:27:06 pm
content: I still can't see what is going on. I do not want to destroy this trying to get it apart. I am not sure if HP has parts to fix it or not. I would like to see one, touch one to see what is missing. Thanks Mike

author: tggzzz
author_rank: Super Contributor
timestamp: March 29, 2020, 02:38:40 pm
content: Do you have parts 8 and 9 in that diagram? If not then you will probably have to fabricate something.I've successfully 3D printed things like part 8 in SLA before; they are very cheap from DirtyPCBs, but can be slow in arriving. An altenative material is Shapeways sintered nylon (whatever they call it this month). It may be necessary to be careful that a homebrew sleeve doesn't increase the tip capacitcance.As for the parts 9, you may have to turn those yourself, or perhaps a piece of piano wire could be coopted. Don't attempt to cut piano wire with ordinary diagonal cutters.

author: WB8PFZ
author_rank: Regular Contributor
timestamp: March 29, 2020, 04:57:40 pm
content: I think 8 is broke and I do not have 9. It looks like 8 screws onto 7? Would that be correct? Mike

author: tggzzz
author_rank: Super Contributor
timestamp: March 29, 2020, 06:17:19 pm
content: Quote from: WB8PFZ on March 29, 2020, 04:57:40 pmNo idea. You have one to look at, I don't.

author: WB8PFZ
author_rank: Regular Contributor
timestamp: March 29, 2020, 06:27:25 pm
content: Well since mine is broke it is hard to tell how things screw together.

author: WB8PFZ
author_rank: Regular Contributor
timestamp: May 22, 2021, 05:49:57 pm
content: Found a working probe on Ebay. The first one has a broken tip. Does anyone repair these?

author: Xtremexp
author_rank: Regular Contributor
timestamp: June 16, 2021, 05:19:53 am
content: Hi All,I also bought 41800A probe from ebay, the tip was broken but luckily the broken piece was with unit and I glued it together. the probe looks brand new but it did not worked.So I start debugging and found that the power supplies of -7 and +9V is not correct on probe, I am reading -7V and +3V, has anybody faced same issue and fixed it? it would be really helpful. I did not find any schematic either.Regard,
Help with ic chip (HP Probook x360 440G1) - Page 1
Forum section: electronics / repair

author: zabounis
author_rank: Newbie
timestamp: November 15, 2022, 05:49:04 pm
content: Hi, this is from an HP Probook x360 440 G1 motherboard (L28241-601).As you can see on the picture, i'm trying to source the specific blown chip. I cannot read whatever is printed on the chip. The only digits visible are: "08" FM. Does anybody have a slight idea what is this chip or an alternative one. Seems like a driver for the above mosfets.

author: fzabkar
author_rank: Super Contributor
timestamp: November 15, 2022, 06:14:44 pm
content: Are you saying that this single chip drives both MOSFETs?ISL95808HRZ-T, Renesas, High Voltage Synchronous Rectified Buck Dual MOSFET Driver, marking 08, DFN-8:https://www.renesas.com/us/en/document/dst/isl95808-datasheet

author: zabounis
author_rank: Newbie
timestamp: November 15, 2022, 06:23:29 pm
content: Ι assume yes. There is no other ic driver chip around them, and it is exactly above them. Also i can see a trace from the second mosfet's gate going directly to one of this chip's legs. The other gate of the mosfet dissapears in a via. I will check with the multimeter to see if it also ends up to this chip.

author: fzabkar
author_rank: Super Contributor
timestamp: November 15, 2022, 06:35:28 pm
content: See my edit.https://ae01.alicdn.com/kf/Hdbd6f0579c334d10af413404c50f1d5c1/Nuevo-ISL95808HRZ-T-ISL95808HRZ-ISL95808H-imprimir-08-808-QFN8-de-alta-calidad-en-stock.jpg(photo)https://www.mainlaptop.vn/forum/uploads/2021/09/Vegas-Turis_MLK_KBL-R_-_17841-1.pdf(schematics for different mainboard - see page 40)

author: zabounis
author_rank: Newbie
timestamp: November 15, 2022, 06:43:32 pm
content: Cheers mate!!!It seems like this one. i checked that Pin 1 and Pin 5 are the gate driver pins and yes this little guy is driving both mosfets.
Help with identification of SMD RF switch - Page 1
Forum section: electronics / repair

author: nielsm
author_rank: Newbie
timestamp: January 22, 2022, 10:54:36 am
content: Can anyone help with the identification of this SMD component which I think is a SPDT RF switch from the rf board of a Viavi JDSU JD785A spectrum analyser?I've searched through the Analog Devices, Macom and Mini-Circuits catalogs but cannot find anything close to the same pin arrangement. I've also tried a couple of the SMD lookup sites. The board was manufactured in 2013 so it could be an obsolete part?Thanks in advance.

author: daisizhou
author_rank: Super Contributor
timestamp: January 22, 2022, 01:13:37 pm
content: https://pdf1.alldatasheet.com/datasheet-pdf/view/413827/MA-COM/MASW-008322-TR0500.htmlMASW-008322-TR0500https://item.taobao.com/item.htm?spm=a230r.1.14.16.74a35d40SgTu0n&id=630350251244&ns=1&abbucket=8#detail

author: nielsm
author_rank: Newbie
timestamp: January 22, 2022, 07:04:07 pm
content: daisizhou - thanks for your help
Help with identifing this component - OPTO 8000 frequency counter - Page 1
Forum section: electronics / repair

author: Bargainhunter
author_rank: Regular Contributor
timestamp: November 21, 2022, 02:19:48 am
content: Can anyone identify this component? I have an Opto 8000 frequency counter for repair. The parts list and schematic I have downloaded is a different version than what I have. There are two of these parts marked 1mO 16/v and a 4700uf 35v electrolytic on the power supply board. They appear too large for a 1uf 16v electrolytic It measures about 1-1/4" long by 3/4" in diameter.Does anyone have this model frequency counter or know what this component is?Thank you,Chuck

author: Martian Tech
author_rank: Regular Contributor
timestamp: November 21, 2022, 03:15:15 am
content: Could it be 1000 uF (i.e., 1.0mF)? Just a guess based on what you said...Do you know what the power supply voltages are?

author: fzabkar
author_rank: Super Contributor
timestamp: November 21, 2022, 04:09:46 am
content: https://www.vpcentrum.eu/1000u-16v-tf008-elektrolyt-kond-axialnihttp://www.avelektronik.cz/-kond-1m0-1000uf-25v-tesla-axialni-te675It does appear to be a 1000 uF electrolytic.There is an 880-page Tesla catalogue (1989, Czechoslovakia) which has datasheets for these capacitors ( page ~600):https://pdfcoffee.com/tesla-katalog-5-elektronicke-souastky-1989-tesla-eltos-1989-cz-scanned-by-elped-pdf-free.htmlThey use mO and uF to denote the capacitance.

author: coromonadalix
author_rank: Super Contributor
timestamp: November 21, 2022, 11:36:21 am
content: here's the schematicscan you tell us it's pcb number position ie: like c21 ??the biggest capacitor is 2200 uf C18https://w5rkl.com/wp-content/uploads/2015/02/Opto-8000-manual-with-schematic-and-parts-list.pdf

author: Bargainhunter
author_rank: Regular Contributor
timestamp: November 21, 2022, 03:06:22 pm
content: Thank you for all your help.The components are listed as C2 and C3. C1 is a 4700uf 35V electrolytic. The manual listed on the internet is different than the model I have. The manual I downloaded shows the model as 8000.1A. I must have an earlier or later version. Also the model I have has a LM309K 5v regulator. I believe they may be a 1000uf 16v as others have posted.Chuck
Help with identifying a part - Page 1
Forum section: electronics / repair

author: lmagalhaes
author_rank: Contributor
timestamp: October 15, 2019, 11:28:58 am
content: Hi there,I have an Asus tablet that stopped charging and when I opened it, it had a broken inductor close to an IC. I was trying to look for the IC online to try and make up the value of the inductor so I could order a new one and solder it, but I can't seem to find it. The only marking on the IC is "LHR". Does anyone know what could it be?Thanks in advance,Luís

author: amyk
author_rank: Super Contributor
timestamp: October 15, 2019, 11:37:01 am
content: That wouldn't be a regular inductor but a common-mode suppression choke.The IC is aTS3USB221AUSB multiplexer.

author: lmagalhaes
author_rank: Contributor
timestamp: October 15, 2019, 11:47:25 am
content: It's weird since the choke would short the D- to the OE on the microcontroller side right ?

author: amyk
author_rank: Super Contributor
timestamp: October 16, 2019, 01:22:32 am
content: Quote from: lmagalhaes on October 15, 2019, 11:47:25 amYou didn't notice the tented via
Help with identifying an SMD diode? - Page 1
Forum section: electronics / repair

author: rfengg
author_rank: Regular Contributor
timestamp: August 04, 2025, 08:45:32 pm
content: Hi there,Could someone help out on the identification of diode D6 marked "W1" on the attached pic? The diode is physically broken and searching SMD codes shows it may be a zener. There is a 20 ohm resistor shunted to D6. This board came out from a Sonance subwoofer.thanks

author: Potential Resistor
author_rank: Contributor
timestamp: August 04, 2025, 09:02:02 pm
content: Saw this whilst having a search (see attached pic)

author: rfengg
author_rank: Regular Contributor
timestamp: August 04, 2025, 09:47:50 pm
content: Thanks @Potential ResistorFound another manufacturer called Topdiode and they seem to have W1 on their 1N4148 as well.
Help with identifying an SMT MOSFET? - Page 1
Forum section: electronics / repair

author: rfengg
author_rank: Regular Contributor
timestamp: December 26, 2024, 08:41:50 pm
content: Hi there,Could someone throw some light on what the part number of attached pic could be? It reads to me as 1D (45) and GF009 and may be a MOSFET?The manufacturer logo is that of ST Micro.thanks

author: wraper
author_rank: Unknown
timestamp: December 26, 2024, 08:54:34 pm
content: STS1DNC45https://www.lcsc.com/product-detail/MOSFETs_STMicroelectronics-STS1DNC45_C501060.html

author: rfengg
author_rank: Regular Contributor
timestamp: December 26, 2024, 09:00:10 pm
content: Wow @wraper.....thanks a lot bud.....that was quick!!!
Help with identifying components!!! - Page 1
Forum section: electronics / repair

author: rfengg
author_rank: Regular Contributor
timestamp: April 13, 2024, 12:21:47 pm
content: Need your help with identifying 3 components from an audio amplifier.Pic 1) Q4 which is marked as DG S19. A similar part on the same board measures as a PNP BJT but Q4 has a short on it.Pic 2) D5 which is marked as N2 Y5. I cannot seem to turn on any diode junction with a multimeter diode check.Pic 3) Fuses F1 and F2: I think these are 5A slow blow fuses from Littelfuse but I am not sure which series they are from. Littelfuse usually marks the series number on the fuse body, but there is none here.

author: fzabkar
author_rank: Super Contributor
timestamp: April 13, 2024, 05:06:51 pm
content: http://markingcodes.com/search/c/dgDG = BFN17https://aliffs.utsource.net/ProductPic/201211/01/f_2a88ce2880fd4e519fdb28f3e738180c.jpg?x-oss-process=style/_410x315(photo)https://www.diodes.com/assets/Datasheets/products_inactive_data/BFN17.pdf(datasheet)Numerous candidates for Y5 here:http://markingcodes.com/search/c/y5

author: rfengg
author_rank: Regular Contributor
timestamp: April 13, 2024, 05:54:23 pm
content: @fzabkar You are a lifesaver
Help with improving amplifier bias scheme - Page 1
Forum section: electronics / repair

author: reddish75
author_rank: Regular Contributor
timestamp: April 15, 2020, 08:53:21 am
content: Hi,I'm looking for any help or pointers on how the bias scheme could be improved in this circuit, as the diode strings are connected to the heatsinks it's not overly stable, varying +6-7mv on idle, the amp runs hot as it is up to 50oc at idle.

author: shakalnokturn
author_rank: Super Contributor
timestamp: April 15, 2020, 10:57:11 am
content: Is that a Luxman?Without looking into improvements, regarding bias issues the first things to look at are the diode strings that often go intermittent and the bias trimmer itself.

author: reddish75
author_rank: Regular Contributor
timestamp: April 15, 2020, 11:05:37 am
content: Thanks for the reply,The amp is a Kenwood l01, with a funky Heatpipe for cooling. The issue is on both channels so i'm assuming that the diode strings are ok, and the trimmers are new Bourns sealed types.Could replacing the Bias transistor be worth a try, replacing it with something that can dissipate the heat better?

author: shakalnokturn
author_rank: Super Contributor
timestamp: April 15, 2020, 01:17:38 pm
content: I have one of those around, a friend's that has been waiting for repair a couple of years now. It has a burn hole in the PCB, I just can't get down to it...I repaired one in the past with a (initially) blown output stage, a bloody mess... Being DC coupled it blew transistors out quite far back.You say it runs hot, is the idle current adjusted correctly and stable?If both channels have the same problem, I'd first suspect things common to both (i.e: power supply) of course it could just be bad luck and you have the same faults independently.Try scoping both outputs simultaneously to see if the mV variations follow one another or if they are pretty much independent (if they are linked to idle current variations there could be some interaction from one channel to the other through the power supply).The 5 legged Sony transistors used in the differential pairs in amplifiers of that era are a very common problem. Usually causing crackling sounds, or worse on DC coupled designs.
(Resolved) Help with KSGER t12 soldering station - Page 1
Forum section: electronics / repair

author: Johadart
author_rank: Newbie
timestamp: January 11, 2024, 03:01:53 am
content: Hi all, just wondering if anyone knows the problem with my unit, I was using it yesterday, now when I turn it on, it just comes on and off in a loop?

author: DavidAlfa
author_rank: Super Contributor
timestamp: January 11, 2024, 03:41:39 am
content: Remove the handle, the T12 cartridge might have shorted internally.If the 24V from the PSU are stable, check the 3.3V regulator, they're known to run hot and fail sometimes.

author: Johadart
author_rank: Newbie
timestamp: January 11, 2024, 03:57:20 am
content: Thankyou, yes when I unplug the handle from the unit it becomes stable, so I’ll check the 3.3v regulator.

author: DavidAlfa
author_rank: Super Contributor
timestamp: January 11, 2024, 05:05:41 am
content: Then it's not the 3.3v regulator!Insert the handle with no tip to make sure the wiring is ok, then try other tip.Measure the current tip resistance, should be about 8 ohms.

author: Johadart
author_rank: Newbie
timestamp: January 11, 2024, 05:32:17 am
content: HI Davidafa, yeah I put new tip in and works fine, the old tip I’ve thrown away, much appreciated for your help, thank you 🤙🏼😊
Help with manufacture of the 3.5mm Headphone Jack from DJI Goggle v2 - Page 1
Forum section: electronics / repair

author: saibot1988
author_rank: Newbie
timestamp: August 28, 2022, 08:16:37 am
content: Hello,On my DJI Goggles v2 the Headphone Jack (4 Pin) got defective after inserting a 3.5mm plug which had bad manufacturing quality...Does anyone knows the manufacturer of this headphone jack? I already searched on Mouser, Digikey and LCSC but not found a matching one.BTW I know there are replacement PCBs available. I would like to prefer replace only the faulty jack.

author: mag_therm
author_rank: Frequent Contributor
timestamp: August 28, 2022, 09:54:48 am
content: First try searching for "trrs 3.5mm Jack"If you can't find one with same pcb pinout, try"trrs 3.5mm breakout Jack" eg Proto Supplies.That might enable you to solder wires onto the pcb, however it needs more space.
Help with mosfet replacement in UPS - Page 1
Forum section: electronics / repair

author: benzi
author_rank: Newbie
timestamp: April 20, 2020, 12:19:07 pm
content: Hello!I'll be upfront and admit I'm probably just a noob.During maintenance I did an oopsie and I've blown up mosfets in UPS APC SUA1500RMI2U. Upon visual inspection boards seem fine except blown mosfet I've identified as Fairchild Semiconductors HRF3205.Now, going with assumption of me being an idiot and improperly powering on the UPS or not noticing I've shorted something being the failure mode I'd like to ask about replacement part.Looking at similar parameters and local availability I've found IRF3205PBF being quite similar to HRF3205, however with some discrepancies. Here's comparison link to Digikey for your conveniencehttps://www.digikey.com/short/zp01vpMy questions are:- Are differences in Gate Charge (146nC @ 10V vs 170nC @ 10V ) and Input Capacitance (3247pF @ 25V vs 4000pF @ 25V) going to cause problems in long term operations?- I presume higher drain current is not an issue, is that right?- Is there something in datasheet staring at me and saying that this is bad idea?

author: keymaster
author_rank: Regular Contributor
timestamp: April 20, 2020, 03:02:39 pm
content: the IRF3205PBF is better (not by much ).the differences in Gate Charge and Input Capacitance , makes it , easier to drive the mosfet.the drain current is the limit , so no problem there either .there is always the possibility that the controller of the mosfet is dead too.look also for short diodes .

author: MarcosL
author_rank: Newbie
timestamp: February 19, 2021, 07:30:36 am
content: I am in the exact same situation, my ups also blew an HRF3205. Did your fix work? Did you have any other problems if/when you swapped the part out?Also, my UPS (BE500U) failed due to repeated on-off cycles from blackouts. All that was plugged in was a consumer grande Asus router.

author: MarcosL
author_rank: Newbie
timestamp: April 21, 2021, 02:08:59 am
content: Wanted to give an update that just replacing the MOSFET did not work. I am sure other stuff had failed as well but it was not worth fixing at that point.
Help with Nvidia GTX 1080 Repair - Page 1
Forum section: electronics / repair

author: MrCravon
author_rank: Newbie
timestamp: September 26, 2020, 01:26:17 pm
content: Hi,I have an Nvidia GTX 1080 Card that died on me a couple of months ago. At the time I didn't have time to look in to it and I bought a replacement immediately. However, now I am thinking the 1080 can be a nice upgrade for my daughter's gaming PC if I can get it working again. I have done some repair work before but usually when I work on boards I have the full schematic available. And I haven't found any very useful schematics online with some google searches at least.When I power up my computer with the card installed the PSU immediately goes in to fail safe mode suggesting there is some short-circuit in the card. If I power up the computer with the card installed but only powered through the PCI slot. There is no failsafe triggered on the PSU. But there is also no screen output. (Maybe that is normal behavior when the card is only powered through PCI) After taking off the cooler and doing a visual inspection of the board I can not find anything obvious. There is no bulging capacitors, no visible charring or visible heat damage and I can't see any solder joints with cracks or significant corrosion.Anyone who has some suggestions on what steps I should take next in order to find the faulty components?I had the following next steps in mind:1. Measure resistance of RAM power rail to GND. I would need some help identifying the correct points to measure without a schematic at hand.2. Try to power the card with my lab PSU with a current limiter set to 1A and look for hotspots on the card. I don't have a good way to measure for hotspots so it would be me touching components with my finger. Not the most accurate way of troubleshooting.3. Just start de-soldering components and measure the values.I am open to suggestions on how to approach this. And if anyone know of what might "typically" be wrong that causes a short circuit on the power input side of the card any help and pointers would be much appreciated.At some point I had some power cables directly soldered to the solder joints on the back of the card to make the card fit in a low profile case. However, they have been removed and the card was working for quite some time after those had been removed.I enclosed some pictures of the card in question if someone want to point to specific components.Thank you for taking the time to read this!
Help with Panasonic SG-K2000 amplifier issues - Page 1
Forum section: electronics / repair

author: chichi1999
author_rank: Newbie
timestamp: August 29, 2025, 12:07:04 pm
content: Hello everyone, I'm having issues fixing this vintage stereo system, its amplifier boards seems to not be amplifying. The audio comes out at super low volume with the max. volume setting (the pot. works correctly). At first I had 20V and a constant hum coming out at the speakers output (saturated amp. I supossed). I changed the electrolytic caps., the 5218P component (TL082 replacement) and the NPN/PNP C1815 and A1015 transistors (this last thing helped with the amp. saturation and I do not have any DC at speakers now), but now the audio comes out super low. I measured the D1265 transistors off-board and they seem to be ok. Can anyone shed some light? Thanks in advance

author: Swake
author_rank: Frequent Contributor
timestamp: August 29, 2025, 07:37:21 pm
content: Is the power supply ok?Do you have a schematic or service manual for this?

author: chichi1999
author_rank: Newbie
timestamp: August 29, 2025, 07:52:26 pm
content: Yes the PS is ok. I could not found the service manual for this model, I just found out that the SG-h10 is not the same as the one I got. My model was commercialized in Argentina in the 80s, I don’t know which is its equivalent model for the rest of the world

author: Swake
author_rank: Frequent Contributor
timestamp: August 29, 2025, 08:22:15 pm
content: You changed the 5218P for a TL082. Is that a genuine TL082 or aliexpress/ebay sourced? Asking because it might very well be entirely fake. How did you identify the 5218P was bad?Do you have a signal generator or a mobile phone with audio output and a signal generation app? This to connect it to the input of the amp.
Help with part ID - Page 1
Forum section: electronics / repair

author: scrubba
author_rank: Contributor
timestamp: January 13, 2021, 06:35:44 pm
content: Having trouble identifying and locating source for electronic component from a sewing machine. It looks like a mini transformer and only marks on it read TYP 90 40/96. Any help would be greatly appreciated. Thanks for reading.

author: bob91343
author_rank: Super Contributor
timestamp: January 13, 2021, 07:39:05 pm
content: Common mode choke?

author: scrubba
author_rank: Contributor
timestamp: January 13, 2021, 08:13:18 pm
content: I'll try researching common mode chokes. Thanks for your input.

author: Grandchuck
author_rank: Super Contributor
timestamp: January 13, 2021, 08:54:32 pm
content: Common mode chokes are often used to suppress line noise. They are used in conjunction with two more capacitors. This looks different to me. But, I don't have a better idea.Can you determine what it is connected to?

author: scrubba
author_rank: Contributor
timestamp: January 14, 2021, 12:51:59 am
content: Thanks for your help. The traces from the four pins of this component lead to resistors, a capacitor, and a diode. (as far as I can tell with my limited knowledge)

author: scrubba
author_rank: Contributor
timestamp: January 14, 2021, 12:59:02 am
content: One more pic from the other side ...

author: bob91343
author_rank: Super Contributor
timestamp: January 14, 2021, 01:06:08 am
content: It appears that the component designations are marked on the board. Is there one for this component? Often the prefix is a clue. Q = transistor, R = resistor, D = diode, etc.Looks like U145...

author: scrubba
author_rank: Contributor
timestamp: January 14, 2021, 01:09:10 am
content: I think it's U145.

author: JohnnyMalaria
author_rank: Super Contributor
timestamp: January 14, 2021, 01:16:57 am
content: Looks like this board (top left):https://www.drdanessmh.com/berninahelectronbds1.htmlYou can buy the service manual for $12:https://berninamanuals.com/Bernina_Service_Manuals.htm

author: scrubba
author_rank: Contributor
timestamp: January 14, 2021, 01:29:26 am
content: Thank you for your suggestions and links. The board pictured says its for a model 1090. I'm not sure if it'll work for a 1260 which is what I'm trying to repair. I have also looked at boards for a model 1230 on ebay, which are similar, but have slight differences in the circuitry.
Help with parts identification - Celestron Microscope repair - Page 1
Forum section: electronics / repair

author: NickFolino
author_rank: Newbie
timestamp: April 16, 2023, 08:29:46 pm
content: I'm trying to repair a Celestron Microscope. I believe someone plugged in the wrong power supply and damaged 2 components. Pictures attached. Any idea what these parts are? Any help would be greatly appreciated!Nick

author: fzabkar
author_rank: Super Contributor
timestamp: April 16, 2023, 11:28:10 pm
content: The marking isn't exactly the same, but it's very similar (WS-nnn or WS=nnn):Richtek, RT8008, 1.5MHz, 600mA, High Efficiency PWM Step-Down DC/DC Converter, 2.5V - 5.5Vin, SOT23-5:https://www.richtek.com/assets/product_file/RT8008/DS8008-07.pdfhttps://www.google.com/search?q=rt8008&tbs=isz:m,itp:photo&tbm=ischhttps://www.google.com/search?q=ws+sot23-5&tbs=isz:m,itp:photo&tbm=ischIf you could provide a full photo, that would enable us to see the parts in context.WS- is RT8008PB (Lead free)WS= is RT8008GB (Green)http://www.smdmark.com/en-US/search/code?id=ws-http://www.smdmark.com/en-US/search/code?id=ws=

author: NickFolino
author_rank: Newbie
timestamp: April 17, 2023, 12:25:35 am
content: Thanks! Here's the circuit. 5VDC comes in at the connector on the left. U5 and U22 are the damaged components I'm trying to identify.Nick

author: fzabkar
author_rank: Super Contributor
timestamp: April 17, 2023, 01:04:03 am
content: Assuming RT8008 is the correct part, and if R11 and R12 are 30D (200kohm) and 01D (100kohm), respectively, then the output voltage of U22, when measured at L4, would be 1.8V.The part marked DE= appears to be a 3.3V LDO regulator.RT9193-33GB, Richtek, 300mA, 3.3V, Ultra-Low Noise, Ultra-Fast CMOS LDO Regulator, marking DE=, SOT23-5:https://datasheet.octopart.com/RT9193-33GB-Richtek-datasheet-12517944.pdfhttp://www.smdmark.com/en-US/search/code?id=de%3DI can't identify U5, but I'm wondering if it is another LDO regulator. I would identify the larger ICs and determine what supply voltages they require. The A106 capacitors appear to be the filters on the Vins and Vouts.Edit:Could U5 be a TC1014-2.5VCT713? That's a 2.5V LDO regulator.TC1014-2.5VCT713, Microchip, 2.5V, 50mA, CMOS LDOs with Shutdown and Reference Bypass, marking A1xx, SOT23-5:https://ww1.microchip.com/downloads/en/DeviceDoc/21335e.pdf

author: NickFolino
author_rank: Newbie
timestamp: April 17, 2023, 10:16:55 am
content: Yes, fzabkar. I think that's it!How did you find these?Nick

author: fzabkar
author_rank: Super Contributor
timestamp: April 17, 2023, 04:35:16 pm
content: http://www.smdmark.com/en-US/search/code?id=a1xx