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 ...

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0
votes
4answers
71 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 ...
0
votes
0answers
7 views

Troubleshooting a port in a USB 2.0 bracket [migrated]

I am currently troubleshooting a single port in a two-port USB 2.0 bracket (example here) that does not work. A USB bracket is a simple device (consisting only of cables and connectors) that connects ...
4
votes
2answers
377 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
130 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
47 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
93 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
104 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, ...
1
vote
1answer
77 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
219 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
204 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 ...
0
votes
1answer
295 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
156 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
176 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
87 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
104 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
956 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
1k 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
172 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
321 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
316 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
452 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
401 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
578 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
328 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
376 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
172 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
338 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
143 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
469 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
194 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
218 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
18
votes
5answers
2k 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
158 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
469 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 ...
0
votes
2answers
195 views

Repairing resistors [closed]

I'm attempting to repair a resistor that was physically damaged by a heavy object. The part is a Yageo CFR-25JB-52-10K and the datasheet may be found here. I've attempted to use Loctite Epoxy Instant ...
2
votes
1answer
443 views

How to find a replacement MOSFET

I have a small, dead power supply for a camera battery charger (cheap replacement, no brand name). I opened it up and discovered that one of the MOSFETs is burned out. The datasheet (in chinese) is at ...
4
votes
1answer
897 views

Resistor in series with primary side of transformer failing

I was given a Trio CS 1554 Analog oscilloscope. It hasn't been turned on for at least 2 years, but probably a whole lot more. Today I plugged it in and it turned on. It was usable for approximately ...
0
votes
1answer
404 views

Replace Expensive Transformer with cheaper alternative? [closed]

I have a range hood that has an expensive (IMO) transformer that has went bad. Here is the link to the transformer that went bad: ...
4
votes
1answer
430 views

A good technique for removing 50-pin SMD CF/MD card slot with Hot air

I have a piece of equipment that has a CF/MD card on it. Somebody tried to force the card in and broke 2 pins off. I managed to replace the two pins temporarily, but it was kind of a hack job, but it ...
-2
votes
1answer
749 views

ATX power supply troubleshooting [parttern of failure] [closed]

I'm troubleshooting a ATX power supply and I found that fuse has gone. Then I replace the fuse, Then fuse burnt very violently. Then I trace the tracks and found that RL207 diodes , 3 out of those 4 ...
7
votes
3answers
723 views

Sensibility and health hazards of reflowing computer PCBs in a domestic oven

This is a bit of a fringe question, SE-wise, but I think EE is the best place to ask it. Some acquaintances of mine had a problem with their laptop - the graphics card stopped working. They've ...
1
vote
3answers
3k views

How to safely discharge high voltage (> 42 V) capacitors?

I have a 1200 watt PC power supply (yeah that's for a gaming rig!). Unfortunately it's failing on me after about 3 years. As the guarantee is over and I don't want to have shipping costs, I want to ...
0
votes
1answer
415 views

Replacement for 5610 Transistor

I have a circuit (from a RC car) that uses a 5610 transistor, which can't find in store. Is there any equivalent transistor? Here are pictures of the board (click here for high resolution images): ...
3
votes
1answer
158 views

Advice needed for replacing old ER3055 transistor

I have a transistor in a guitar amp with the label ER3055 that needs to be replaced. I asked about another transistor that I needed to replace in a post a few days ago here and I tried using NTE to ...
1
vote
1answer
124 views

Is it possible that a new transistor is not good even if a current runs through it?

I just got an NTE121 replacement transistor for an old 2N2148 that was in a guitar amp. It was the only part I replaced and now I have no sound coming from the speaker. I checked every component on ...
6
votes
2answers
362 views

How to find a replacement for an antiquated transistor 2N2148

I need to replace a transistor in my guitar amplifier. The model number listed on the original schematic is 2N2148. It is in a TO3 package and the rest of the specs are listed here. I am having ...
2
votes
2answers
420 views

In this project, where does the rectifier go?

I was a backer of an early Kickstarter project, and now the project leads have dissapeared. Before they left, they offered some advice to fix some of their faulty units. Here's a picture of the ...
-1
votes
3answers
2k views

Olevia model 237-T11 TV won't turn on [closed]

So my Olevia model 237-T11 tv stopped working the other day. Now mind you, I tried everything from unplugging, waiting 30 minutes, replugging it into the outlet, using different power outlets, etc. ...
-2
votes
1answer
282 views

Can I change the capacitor from 1uF 2000 volt to a 2uF 2200 volt? [closed]

I am facing a problem in a pipe welding machine circuit. In this circuit one transformer the in put of this transformer is 400V 3.4kVA and outputs 12V. After this 12V, two capacitors (1uF 2000V) in ...
0
votes
2answers
265 views

Finding Failed Component in broken florescent lantern circuit

Recently, I burned out the circuitry in a florescent lantern by accidentally reversing the polarity of the volts in. The circuit seems pretty simple, a transformer, 3 resistors, 3 mono capacitors, a ...