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 ...

learn more… | top users | synonyms

9
votes
3answers
525 views

What are these cream plastic-like blobs on my circuit board?

I see these white/cream colored blobs all over the board (I've surrounded them with red rectangles in the image above), something which I've never encountered before. They're plastic like in texture, ...
-1
votes
0answers
36 views

What kind of part do I need to repair this speaker? [on hold]

After a period in storage, I've noticed that a line input on one of my Yamaha MSP5A speakers has been damaged. From the manual specs, the input is ...
0
votes
0answers
24 views

seraching for laser diode [closed]

I am searching for a laser diode as a replacement part, but have not had luck identifying it. The small brass component labelled XW080 or 080MX I am not certain, about the centre of the image, with ...
0
votes
1answer
85 views

How can I fix this ESC circuit?

What happened: Two of the blue wires touched while an 11.1v battery was hooked up and POP What's in the photo: Yellow is the heat shrink wrapper I cut open the material with square impressions on ...
0
votes
3answers
83 views

Can this circuit board be repaired?

This is a board out of a Super Nintendo game cartridge. It appears to have damage from a few of the leads, and this game definitely doesn't work when tested. The game is very rare and worth my time ...
2
votes
3answers
621 views

Can a 6.3v capacitor be replaced with a 16v capacitor? [closed]

I'm repairing my old 478 socket computer motherboard and two 6.3v 2200uF capacitors near the CPU are bust. The computer still powers on, but it doesn't pass the BIOS screen without the ps/2 mouse ...
0
votes
2answers
106 views

What component: a glass tube wrapped with a wire mesh and has a single metal pole inside?

I found this while trying to fix my noisy hot/cold water dispenser. It has a blueish glow and makes a loud buzzing noise of around 56-58 Hz. I'm planning to replace it, but there doesn't seem to ...
1
vote
2answers
89 views

Explanation for super-sensitive loose contact inside potentiometer?

Symptom I have a mixing console, where one 6-pin stereo pot is errartic. When I turn it all the way down I sometimes can still hear the left channel at full volume. Explanation The circuit is a ...
0
votes
1answer
53 views

Multimeter reports voltage but no power?

I have an Insteon FilterLinc, which is an electrical line filter. It doesn't work. When I connect a lamp to the "filtered" outlet, I get no power. So I stuck multimeter probes into the filtered outlet ...
0
votes
1answer
58 views

Beginner PCB Repair - Voltage Regulator Issue

During a fault finding mission on my car I found the Vref on a sensor that should be 5V sitting over 7V. I traced it back to one of the modules and found the pcb mounted voltage regulator was ...
1
vote
1answer
95 views

Schottky diode as AM detector?

An old AM radio that passed down to me from my grandparents finally ceased to function after I accidentally dropped it and old parts inside got damaged. I ripped all damaged parts out and replaced ...
0
votes
1answer
83 views

Solution for broken pin repair (SMD(SMT) components)

While I was working with a IS62WV51216BLL-55TLI, I broke off by chance a pin at the base near the component body. that's perfect! LoL! It makes me to think about this question: Can we fix such ...
0
votes
0answers
56 views

How should I repair my old Geiger-tube?

I have an old soviet Si-3BG Geiger-counter tube. Both ends of the glass tube have a metal cap which serve as the two electrode. This cap was glued to the glass ...
0
votes
1answer
68 views

What is the device used to diagnose bad eletronic hardware? [closed]

I'm quite new to electronics repair and was wondering what is the device that is used to diagnose electronic hardware such as chips and power voltages. I'm not talking about a multi meter, but the ...
0
votes
2answers
86 views

Soldering problem when changing component on tablet board [closed]

I needed to change demaged Schottky SMD diode (2.2x1.2mm) at chineese tablet board. But I was not able to melt solder even I used hot gun at 400°C or soldering tip at 480°C. Finally I more or less ...
1
vote
0answers
96 views

What is this motherboard component that looks like a bead of solder [photo], and can it be repaired/replaced? [closed]

As you can see, the one on the top is burnt. Whenever I plug the power adapter into the wall, the component releases a puff of smoke and the adapter instantly shuts itself off. The damage to the ...
0
votes
2answers
72 views

How can I fix this Firewire 800 header by soldering? [closed]

Unfortunately I found the headers on my computer's belkin 3-port Firewire 800 all tilted back somehow, and they snapped off when I tilted them forward to where they should be. As a quick fix, I have a ...
0
votes
4answers
161 views

How important is “mm pitch” for a capacitor? [closed]

I want to repair my boiler, so I found this howto. He writes I need a MKP X2, 26.5 x 10 x 19 mm, 0.47 µF 275 V/AC ±10%, 22.5 mm pitch. The closet one I can find ...
4
votes
2answers
396 views

Might swollen caps be working properly? [closed]

I've seen these two swollen caps in a symmetric +12, 0, -12V power supply. The circuit (a theremin) seems to be working properly, but I don't know if that caps are going to cause damage in the ...
3
votes
1answer
153 views

Identify failed component [closed]

Since this is my first question here, I hope this is on topic. The power supply of one of our old CISCO Aironet 1231G wifi access point failed recently, after a power outage. I think that the power ...
-1
votes
1answer
55 views

What values can I change when replacing a 200uH 2Amp coupled inductor?

I am replacing a coupled inductor (with corrosion on it) on a liquid handling robot board, in hopes to fix a blowing fuse problem. The part number is not coming up in any search I have tried so far, ...
1
vote
1answer
117 views

Will a 1950s television still work? [closed]

My company has a Philco Predicta television model H3407 as described here: Philco Predicta description. Will this TV still work with modern broadcasts?
-2
votes
1answer
108 views

Have I destroyed my device [closed]

I have connected a wrong adapter to my Inforce 6410 device. It takes 5V but I have accidentally connected a 19V adapter. The board got heat up and I saw some smoke, now when I connect the 5V adapter, ...
2
votes
1answer
128 views

Cleaning oscilloscope range switches

The various range switches on my oscilloscope obviously collected some dirt over the years. Sometimes the input attenuators show a frequency dependent response (just like poorly matched probe) and the ...
4
votes
3answers
266 views

help for identifying an unknown chip

I've found a burned chip (due to DC power overload) inside the sound card Roland UA-25EX. This is a picture of the part: Can someone give me a hint? I'm not an expert, I want only to find the spare ...
-1
votes
2answers
355 views

How to find a problem on a Non working Yamaha SPX90 (Pro audio) effects unit [closed]

I have an electronic processor unit namely an SPX90 (a 19" pro audio effects unit made circa 1987). I'm a home studio producer and have owned it from new from 1987, but it died a few years ago. Now ...
1
vote
1answer
2k views

How to test capacitors of non working circuit board using capacitor meter?

I bought broken sega megadrive 2 clone console. Something wrong with 7805 IC supply (I changed to another, but no result). But now I want test electrolitic capacitors and resistors, because I thing ...
3
votes
1answer
233 views

Replacement cap (filter / choke) for oscilloscope power supply

My dad's poor old Philips PM3070 scope died in a sizzle and a puff of smoke a few days back, after being sat in the garage for a year or so. He donated it to me and it seemed to work at first, but ...
5
votes
3answers
204 views

Removing solder effectively

I have an Epihpone (Les Paul 100, fairly standard) electric guitar, which over the years have gotten to suffer from a non-functioning bridge pickup. I verified this using an ohm-meter, the result ...
-2
votes
1answer
101 views

How to fix sealed consumer product (headphones)? [closed]

So the cable that connects the speakers on my headphones broke. I can tell it's the cable between them because there is jack input on each speaker and they both play well when connected but the other ...
1
vote
2answers
154 views

How to bypass or replace a defective SMD switch?

I have a wireless keyboard with a defective on/off switch. The switch has a little play, and it's closing the circuit only when it is almost pushed to the extreme position for on. If 0 represents the ...
8
votes
4answers
2k views

How can I lower the chance of burning out capacitors?

I have an AC/DC power supply circuit fitted to many machines, which are all running well within the rated power capability of the supplies. However these keep failing, every one burning out a (large) ...
1
vote
2answers
3k views

Locking ribbon-cable in place

There is ribbon cable which is connected with a locking mechanism as in the picture below. The brown plastic locker is not locking properly, is there a way to get another locker and lock it in place ...
6
votes
2answers
233 views

Servicing mechanical selector switches / rotary encoders

After 15 years of use, one of my Alps mechanical selector switches (metal contact spring dragging across metal tracks) had developed oxidised/dirty contacts. After some cleaning with alcohol and ...
4
votes
1answer
503 views

Repairing a failed generic AC/DC power supply which “ticks” [closed]

This type of death affects a lot of power supplies, Computer power supplies, Monitors, and other mains powered equipment that is stepped down to low voltage, high ampage DC. On plugging in, the psu ...
0
votes
1answer
531 views

How to open a 32" Philips CRT TV for service [closed]

I have an old and faithful (well, until today) 32" Philips CRT TV (32pw9309) that was purchased on 2004 and served me very well since then. Today, while the kids were watching a DVD, we heard a "pop" ...
4
votes
1answer
806 views

Is the Holzer effect the same as the Hall effect? (looking for replacement sensor)

I was looking for a replacement component for what I thought would be a "Hall effect sensor" (used in an electric scooter throttle handlebar). I had bought a replacement throttle about a month ago, ...
2
votes
1answer
817 views

Repairing a heat gun [closed]

I've got a heat gun that has stopped working. Use of a multimeter tells me that there's a single part that is stopping current from flowing through the whole thing. This part is indicated ...
1
vote
1answer
1k views

Identifying and finding replacement for LCD display module

I have a Line 6 POD X3 amp modeler. It has a small LCD display module which was shattered during my last move and the device became unusable. I have attempted to identify the model of this display to ...
8
votes
3answers
409 views

Why might a multimeter ask for “wrong” fuse sizes?

Why might a multimeter ask for the "wrong" sizes of fuses? On the front of my Fluke 87 multimeter, the two probe ports for amperage are labeled as fused at 10A (max) and 400mA (max). When opening the ...
1
vote
1answer
567 views

Repair a xbee wire antenna?

last year I bought a xbee pro s2b, the wire antenna one. After some use, the antenna started to loose, and last week it just broke. Is there a way to repair it? I soldered it again, and it holded some ...
1
vote
3answers
224 views

Identifying SMT element 331K

I am trying to repair a remote from a car lock. The symptoms are that a red led is lit longer than usual after button press and no respond from car lock. It works sometimes. The battery and ...
-1
votes
3answers
533 views

Wires resistant to frequent bending for use in headphones

I'm tired of continuously fixing wire on headphones. Can you recommend good wire that resistant to the frequent bending and thus will be last ultimate replacement as headphone wire ?
0
votes
0answers
153 views

2.1 sound system noise

I have a 2.1 small sound system that makes a high frequency noise when turned on, whether the input is grounded or not. I've opened it and measured the frequency of that noise with a scope and it is ...
7
votes
5answers
537 views

Does it make sense to measure components in-circuit in order to prove non-functioning?

When an electrical circuit is not working properly does it make sense to use a multimeter to measure/test the individual components in-circuit (without soldering them out), e.g. measure transistor ...
0
votes
2answers
257 views

How to fix a broken Sharp CD-BA150 stereo with the help of a service manual? [closed]

I have a Sharp CD-BA150 stereo. Since the cd and tape decks are completely busted (doesnt play, rewind, etc.) and I have nothing to lose (I plan to throw it out anyways) I want to try to repair it ...
2
votes
5answers
253 views

Want a Second Look Do all of these Capacitors Need to be Changed? [closed]

I pulled apart my monitor to check the capacitors and I think almost all of them need to be replaced but there are a couple I am not sure about
19
votes
5answers
3k views

Wire broke off and stuck in a header

I'm working with an Arduino, and one of the stripped portions of the wire broke off at some point and managed to get pretty wedged into the 5V pin slot. Obviously, this wouldn't matter as much for a ...
0
votes
2answers
165 views

Date of introduction of TO-92 transistors

I'm trying to date a circuit from an organ. It contains transistors in a TO-92 (plastic) package. Approximately when did these transistors first appear?
3
votes
1answer
696 views

RFID coil - ends broke, can I resolder?

The 125kHz RFID scanner / reader device I have, has a coil like this: NB> Don't have a good camera handy at the moment, so had to share a cropped image from Alibaba, but the pic is very close to ...