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Questions tagged [repair]

Questions relating to electrical/electronic repair. Questions on the repair of consumer electronics, appliances, or other devices must involve specific troubleshooting steps and demonstrate a good understanding of the underlying design of the device being repaired. Please ensure your questions are somewhat generic in nature so they are likely to help future visitors and not too localized to a specific piece of equipment.

0
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2answers
40 views

VI component tester not working properly when capacitor is placed parallel with diode

I am trying to repair mainboards with VI component tester. (Such as this device and that device.) I check the characteristic VI curves of the components on the card and identify the defective parts ...
1
vote
1answer
37 views

Mosfet testing for short from youtube repair video

In the 23:40 of the youtube video https://youtu.be/YQ7SXJqIpzs , the presenter does a p-channel mosfet test for short, using his bench power supply on the circuit. From what i understood, he ...
1
vote
1answer
49 views

RIFA PME271M547 replacement

I just broke my sewing machine (it's an old Viktoria machine about 30-40 years old) and now I am looking for a replacement safety capacitor. The one installed is a RIFA PME 271 M 547 paper capacitor. ...
-1
votes
1answer
72 views

Clean/repair/replace the carbon pill of a rubber keypad

I have several devices (calculators, remote controllers, …) with rubber keypads where some keys are dysfunctioning. As I understand it, this is because of the carbon pill since things work fine if I ...
3
votes
0answers
42 views

Bluetooth speaker works only when aux is plugged in [closed]

Plot Recently got this Bluetooth/FM speaker with a built-in microphone from my friend to try repairing it. He said that it's battery was swollen up so he dumped the battery and never used the speaker ...
1
vote
0answers
50 views

DC permanent magnetic motor control issues

We have a 180 V dc permanent magnet motor. When engaging the control board while the motor is hooked up. The output to motor drops out and reads no voltage. If I take the motor leads off the ...
1
vote
3answers
74 views

solder-bridge at ribbon-connector?

I am currently trying to repair a pen-tablet-monitor, which has what i call a 'blind/dead row'. Meaning that i can draw everywhere, but there is this one row, where any input is either picked up by a ...
-1
votes
1answer
60 views

Subwoofer amplifier IC repair? [closed]

I bought a subwoofer as is. The sub worked, but the speaker terminals didn't. I took a look inside and the amplifier IC(TDA 7265) looks like it shattered somehow. Any ideas what could have ...
12
votes
1answer
215 views

Troubleshooting a faulty filter circuit in a PAL CRT display

I have an old CRT monitor (Phillips CM8833) which I am attempting to repair. When displaying a composite PAL signal, it only shows a black and white image, but it is still able to display RGB signals ...
2
votes
3answers
90 views

Soaking phone motherboard in isopropyl to fix potential corrosion

Is it advisable/safe to soak my phone motherboard in an isopropyl alcohol bath? I dismantled it after water damage occurred and it now powers on fine but my cell signal isn't consistent. I was ...
0
votes
0answers
46 views

Insights required to repair my Agilent YIG oscillator

I know, it's probably no chance. But let me try. The model is HP-Agilent 0955-0520, Y088-4258, that can be bought for 600-900$. Here is a picture. When I bought the oscillator, I performed multiple ...
3
votes
1answer
76 views

Component identification, on USB 2.0 data lines

The component i'm trying to identify is on the usb 2.0 D+ and D- lines of a nintendo switch, its got two ground connections and has the letters DUG on it. Can anyone identify this component?
0
votes
0answers
64 views

Would a device with different power rails become one if both rails are shorted to ground

I'm trying to repair a nintendo switch that seems to have multiply shorts to ground. The shorts to ground are on the 3v3 rail and on the 1v8 rail. I seem to be getting continuity between the two ...
0
votes
1answer
68 views

Repair lifted ground pad on power amp

I'm repairing a 250W bass power amp board and one of the problems is that the pads for two ground wires have lifted off the board. It looks like it has had something of a bodge repair done before and ...
2
votes
1answer
96 views

Faulty temperature sensor on PCB - lights keep blinking, how to replace this?

I’ve been working on a broken continuous operating high power LED system - it starts blinking when powered. This was an indication of overheating and it was clear that the cooling fans have stopped ...
13
votes
4answers
4k views

How can I cover PCB burn marks to identify burns later?

I'm repairing a receiver from the 1990s that has a few burn marks on the PCB where a few transistors overheated. After replacing them and any other offending circuitry I'd like to be able to know if ...
3
votes
1answer
128 views

Is it the crystal / quartz?

I have a simple gadget (called "Fridgezoo") that talks when the fridge stays open. I always hated it, but my sentiments are with it (hey, it talks!) so I want to repair it. What's the problem? It ...
1
vote
1answer
78 views

Injecting power into circuit to find a short to ground

I'm trying to find a short to ground on a Nintendo Switch of which there are no schematics. The short is present on the 3v3 line. What I would like to do is inject power into this line from my ...
0
votes
1answer
96 views

Control board powered up with reverse polarity. power transistor blown. Is this repairable? [closed]

My dog chewed through the power cord. I 'repaired' it not paying attention to polarity. It was a 2A, 9V wall wart type power supply. The motherboard is from an elliptical exercise machine. The one ...
0
votes
2answers
98 views

Replacing a Capacitor on an Onkyo HT-R960 A/V Receiver

I have an Onkyo HT-R960 receiver that's been acting very flaky for the past couple of months. I've had to let it warm up for several minutes before being able to use it. I would also have to turn it ...
2
votes
1answer
72 views

Help Identifying a component for PCB repair

I'm helping a friend by attempting to repair this display PCB. It uses 24vac input and he accidentally hooked it up to 120vac. I am trying to identify the two components in this picture under the ...
2
votes
1answer
74 views

old 80C31 circuit not working. EPROM data retention issue?

I have an old piece of pro-audio gear in for repair. It dates from 1990. It was a fairly high-end piece of gear at the time and still has some value so it is worth repairing. But the symptoms I see ...
0
votes
1answer
121 views

How to solder this broken Gameboy Color part back on?

I'm trying to repair a GameboyColor where a part that held a battery broke off. I tried soldering it back on but it didn't stick. (I'm new to soldering) I took some pictures, any feedback and advice ...
0
votes
2answers
59 views

Help identifying replacement regulator

I'm doing some proactive maintenance on a vintage games console from the late 70s. There are a couple of linear regulators which I thought would be prudent to replace whilst I'm at it. Unfortunately ...
1
vote
1answer
176 views

How to test a MOV with no visible damage

As far as i know cumulative degradation occurs in a MOV when multiple surges appears in a circuit, A way to minimize this degradation is having multiple MOVs in parallel. This kind of damage can be ...
1
vote
1answer
339 views

Identifying strange burnt resistor color code

I'm trying to figure out the resistance of a burnt resistor in the PCB of a Hoover FD22G 011 (a cordless vacuum cleaner, with rotating brush; should be the same as the Deik ZB1516, which is the actual ...
1
vote
1answer
64 views

Help identifying SMD on USB Circuit (Wacom Intuos 5 - PTH850)

My Wacom Intuos 5 - PTH850 Tablet have one the following SMDs (the lower one, USB Data -) cracked. Could you help me identifying which component is? I know each component bridges USB data + with ...
0
votes
1answer
50 views

Where might the fault be in this battery checker circuit from an old camera? [closed]

I'm repairing an old rangefinder camera, a Canonet QL17 GIII. I have had to do a lot of internal rewiring. All is now working, except for the battery checker functionality. I've included that part of ...
2
votes
1answer
78 views

Replace bad voltage regulator with another one that have lower output current

I need to replace a shorted TL750L05 +5V voltage regulator with a new one. The problem is I can not easily find a replacement part that has the same features. I found the LM2931M-5.0 but is rated at ...
2
votes
1answer
97 views

repairing damage: what size ceramic bypass capacitor

Repairing a motor control board from a washing machine. A 1206 ceramic cap was burned up, there's a bulk electrolytic in parallel, rated 200v 1000uF. I've attached the example schematic for the ic (...
1
vote
1answer
68 views

Convert a blender into a dimmer lamp

I was sitting around and suddenly wanted to convert my old blender into a lamp. The control panel would act as a dimmer switch. (And maybe the pulse button would be a big hit at raves.) Can I just ...
1
vote
4answers
815 views

Replace a one shot thermal fuse with a resetting one [closed]

My mother owns a device for drying fruits and stuff. Now every year or so, the thermal fuse breaks. I'm always checking if the fan is damages or something else, but the device is always fine. It is ...
1
vote
1answer
339 views

Weller wes51 issue

My soldering station is a Weller WES51 for a long time. Today the station died, the LED didn't turn on and the tip doesn't heat. I opened the station and checked the transformer power switch and ...
1
vote
1answer
146 views

Identification of 5 band Resistor from power supply

This Resistor is not functioning The 4th band is Gold, I've read that means it's an exception. The 3rd looks to me as silver, not gray, this is why I've added a picture. I'd like to replace it, so ...
2
votes
3answers
1k views

Troubleshoot a backplane

I have built a simple bus backplane from stripboard and 40-pin female headers for a computer project I am working on. When I tested the backplane to make sure that it functioned, I found that it's ...
0
votes
1answer
70 views

Identifying damaged, burnt out, or missing components [closed]

Is it possible to deduce the identity of damaged, burnt out, or otherwise missing components (or suitable substitutes)? For example, below is the PCB of a 2 speed electric razor I've disassembled. ...
6
votes
4answers
1k views

Causes for a burned up flyback diode on a relay?

I'm repairing a control board for a premium washing machine (model #s at bottom for anyone that's interested). The machine was displaying an error code for relay failure. I took the board out of ...
2
votes
1answer
134 views

Autopilot gradual failure--help me guess what might be going on

Executive summary: Old autopilot for a boat, now drifts constantly to the right; I'd like suggestions on what might be wrong, and what some of the parts might be. Details: I've got an Autohelm 3000 ...
0
votes
1answer
208 views

Repairing an RFID antenna? [closed]

I have an RFID antenna that seems to be on a custom PCB. The issue I have is that the antenna on one side works fine, but the other side does not. I'm not sure if it is even possible or worthwhile to ...
0
votes
1answer
283 views

Glue/adhesive/epoxy for soldering a mems microphone

I have read a lot of articles on epoxy and glues for PCB especially with a ripped off pad. I am in the same situation myself and was hoping to get some suggestions here. . The mems microphone looks ...
0
votes
0answers
112 views

lecroy 9314l power supply repair

I've been trying to repair my lecroy 9314l for the past couple of days and i've sort of run into a wall. out of ideas. The power supply started to fail a while ago. It wont turn on when i connect a ...
0
votes
2answers
70 views

How can I mechanically secure a headphone cable after soldering on a new connector?

My headphone (Sennheiser HD 265) has a socketed connection between cable and headphone. The headphone cable had come loose, so I bought a new connector and soldered the headphone cable to it. The ...
0
votes
1answer
76 views

transistor replacement dp35dp

Hello I have an old Intel Motherboard DP35DP, I was using this board as a file server using RAID (Its crucial to get that RAID array working again). It seems like the culprit is a transistor, its ...
8
votes
2answers
2k views

How can I fix these broken wires?

I have two CPU fans which have been damaged. In one the wires were separated in the middle, in the other they were separated at the solder contacts. I have very little soldering/wiring experience, how ...
0
votes
2answers
92 views

How to diagnose powering damages and protect again surges?

I wanted to operate remotely a motor which is controlled by a manual key switch (still in place in case the automated way fails - which happened). The switch: I though by replacing it by basics ...
1
vote
1answer
87 views

Repair a 220V PCB trace

I had a water issue with a PCB power strip that has a PCB inside. About half the width of the 220Volt traces got connected and burned so "luckyily" nothing else broke as the fault stopped there. The ...
0
votes
0answers
54 views

I'm having trouble with a Zif cable on a Nikon coolpix S3700 because it appears to have no locking flap

I'm trying to repair an S3700 the buttons (record ect.) stopped working and when I took it apart to clear the dust out I accidentally removed a zif cable and now I can't reconnect it. The actual ...
3
votes
1answer
80 views

Repairing a PS/2 mini-DIN connection w/o clock pulses

I have a Fanatec CSR racing wheel with an optional sequential shifter. Since I last used them I lost the stock PS/2 cable and haven't been able to locate it. I bought an off-the-shelf PS/2 cable but ...
0
votes
1answer
56 views

Glue used to adhere cellphone / laptop components (not screen)

What type of glue is used to adhere cellphone (or laptop) components (excluding the screen which has its own speciality glue)? I'm talking about the sticky, but not too sticky glue used to hold things ...
0
votes
1answer
68 views

Replacing an old dart board ribbon connector - need advice

I hope this makes sense but I have an old dart board that is having some issues I believe is related to the cable in the link below. The cable is a ribbon cable I believe and toward the bottom there ...