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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5answers
96 views

Switching power supply only works when warm

Update With the multimeter and a steady hand, I've found the 3843B PWM controller Vcc pin is 12V when the supply is on, and 8.2V when it is plugged in but cold. Datasheet says it needs 8.4V Vcc to ...
1
vote
0answers
80 views

Need help repairing adjustable DC power supply stuck on 48V

I have a cheap benchtop dual-output adjustable DC power supply. One of the outputs is working alright, the other one "burned out" when it was left loaded somewhere near 80% of its maximum for 24 ...
2
votes
2answers
359 views

Accidentally removed SMD pad

I had been attempting to desolder some SMD ceramic capacitors off a PCB to measure their capacitance. Unfortunately I am quite new to soldering and have managed to screw up. The below picture shows ...
1
vote
2answers
345 views

What is the correct replacement for this mosfet?

I'm trying to repair a broken DC-ATX power supply that I have. After a bit of searching for faults I believe I have tracked the problem down to one of the MOSFETs. I would like to try replace this ...
0
votes
1answer
44 views

Wire laptop power switch to another switch

A little background to my question: I got a laptop some time ago from my grandparents because the screen was broken and they didn't want to fix it. Being your typical tech geek, I already have a ...
0
votes
2answers
113 views

Please help me identify the SMD component in the picture (or help me fix my Wacom)

Could anyone help me identify what type of SMD component the one in the red circle is? The label seems to be ID but I can't really tell very well because it's so small. My guess is that it's a diode ...
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votes
2answers
88 views

How do I identify a burnt out component? [closed]

I was given a project completed by another group, they had left school and I was taking over the project from them, with the information that it is not working properly because "something burnt out or ...
10
votes
3answers
210 views

Seeking advice on resistors in switching power supply

I am trying to repair the power supply in an LCD monitor. It is a fairly basic design around an OB2268AP in the 20-30 Watt range. The power supply had failed spectacularly because the main MOSFET ...
0
votes
1answer
55 views

Electronic soldering and repair for a newbie

So, recently, I've been trying to get more skilled with electronics to prepare me for college, starting with soldering. I mentioned this to someone I know, and he gave me his broken E-Cig, saying I ...
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votes
1answer
51 views

Need help with replacing a headphone jack [closed]

I have found a ton of guides to do this, but i don't have a store bought connector so i simply ripped the stock one open. It looks like this (found the pic on the internet, not mine): ...
0
votes
3answers
84 views

LED circuit with epoxy and (broken?) transistor

I'm trying to repair this battery-powered LED bike light but do not really understand the circuit. Positive terminal middle left, negative bottom left. Momentary push switch at the top, transistor ...
0
votes
2answers
156 views

How can I repair a Goot PX-201 soldering iron which was exposed to too high AC supply voltage? [closed]

I had a stupidity to plug 100V Japan version of Goot PX-201 soldering iron to 220V. It heated up for a second, but that was it, it no longer heats up. I tried to disassemble it, hoping to find a ...
3
votes
3answers
288 views

What is the science behind percussive maintenance?

On electronic devices in the '80's, electronic malfunctions could sometimes be temporarily fixed by physically "hitting" the device. For example, I once had a colour TV - "ECTV" (from Electronics ...
1
vote
2answers
66 views

Determining which diode I need [closed]

I have the following board with the below diode: One diode fails circuit testing and needs replacing, but how do I find out the specification of the diode I should buy to replace it? (it is for a ...
0
votes
0answers
61 views

Testing RF Diodes (“Hot Carrier Diodes”)

I am in the process of fixing an RF mixer (sampler) in HP's 5257A Transfer Oscillator. It contains two diodes, both in series with a 2.2 kΩ resistor. The circuit is built to work up to 18 ...
0
votes
1answer
73 views

Help identifying K1P Z4 transistor

I am not electrically savvy person but I have general idea of what some things are and what they do. I have this nice computer video card that has a broken transistor on the back side and is not ...
1
vote
1answer
198 views

Spark in blender motor [closed]

I was trying to repair a blender whose speed buttons were not working. I thought of removing the speed regulating circuit altogether and directly connect power to the motor. Now, when I run the motor ...
-2
votes
1answer
172 views

Does this TV power supply board look damaged? [closed]

So a suspected power surged killed out Mitsubishi WD-65738 DLP TV the other night. Upon looking up the error code "48", I ended up buying and replacing the main board PWB-MAIN. While this didn't seem ...
0
votes
1answer
140 views

Oscilloscope Repair - Heathkit

I found a great deal on an old Heathkit I0-12 at an auction the other day and decided it would make for a fun project. The unit looks awesome and could probably survive a bomb blast. When I got home, ...
2
votes
2answers
314 views

Best way to fix burnt PCB trace?

So I accidentally burnt a PCB trace and I'm trying to fix it with a wire + some solder. The PCB trace clearly connects two metal pins. My question is, would it be better to completely bypass the ...
0
votes
2answers
273 views

Help me identify this mystery IC? [closed]

I had a bug (yes, a literal bug) decide it would be a good idea to crawl inside my printer and short itself across two pins on my printer's power supply board. I have pulled the board in the hopes of ...
4
votes
1answer
315 views

What is a good process to replace a discontinued part?

I have been looking about (on the web and printed catalogs) attempting to replace a part that is now discontinued. The experience has been part success - and part failure. A part is available to use ...
0
votes
1answer
64 views

Toubleshooting PCB circuit - strange Zener diode behaviour

I have two units of a device which I shall call deviceA and deviceB. DeviceB is malfunctioning. Therefore I compared the resistance values of the same components on the boards of both deviceA and ...
-2
votes
1answer
127 views

Fix a broken Power Supply using existing connector (Newbie) [closed]

I am hoping to attempt to fix my childrens ride on electric car as the power supply was left charging and has cracked / broken (see pics). I am completely new to electronics, but was hoping to ...
3
votes
1answer
116 views

How to replace a SMD capacitor on a raspberry pi?

(Note: also posted first in raspberrypi stackexchange, but not a single answer yet) While desoldering the GPIO, I accidentally broke the capacitor C13 of my raspberry pi model B (2011.12 Rev7). It ...
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votes
2answers
91 views

Help fixing Honeywell doorbell broken circuit [closed]

My Honeywell RCWL330A1000/N P4-Premium Portable Wireless Door Chime dropped to the floor the other day and has not worked since then. I unscrewed the casing an found a crack in the circuit board which ...
0
votes
2answers
80 views

Trying to Fix my remote for my house Fan, is this component a fuse?

Decided I would try and fix the remote for this 3 speed fan I have a home since it is summer now. Here's the circuitry I'm dealing with here: So here our are some notes: There was some battery ...
3
votes
1answer
182 views

Burned Out Tantalum Capacitor Replacements

I have an old computer with a broken Miniscribe 8425SA hard disk. One of the capacitors has burned out, and need some help finding a replacement. Here are my questions: It appears there are ...
0
votes
1answer
284 views

Replacing a SMD inductor, alternatives?

Trying to fix a board that had a SMD inductor. it was labeled L1 on the silk and there was no marking on the part, and I have no schematics. ...or there may have been markings, but someone tried to ...
0
votes
1answer
312 views

Single LED broken on 12V LED bar?

Modules of 3 LED Simple LED strips or bars that are using 12V input voltage often have the following layout: They consist of modules with 3 LED each, all connected in parallel to the input voltage. ...
1
vote
1answer
83 views

Considerations when repairing dimmer switch

I originally asked this question on DIY StackExchange. So far no answers and a suggestion to try on Electronnics, so here goes: I have an IKEA lamp with dimmer switch which took a knock and ...
0
votes
1answer
60 views

What kind of failures can be explained by this fix?

My Dell PowerConnect 2324 is normally plugged in 24/7. At some point it stopped working (no connectivity, power light out) and I disconnected it from the network and power. Recently I opened it up and ...
2
votes
1answer
124 views

4/5 band resistor - extra black band

I have two resistors which need to be replaced. I tried to determine the value, but it can't make sense of these black bands: For reference the bands are: brown - silver - green - brown - black ...
1
vote
2answers
161 views

nichrome alternatives

I am repairing an AVO multiminor Mk 4 which was in a sort circuit across a car battery while in the 1 amp measuring position. circuit diagram here an obvious casualty was the 0.25 ohm resistance R1 ...
0
votes
1answer
56 views

Tracking a circuit path across a crack?

I am new to the world of electronic repair. I have connected several wires to this board and have been successful in getting the paths across the crack to connect. Is there an easy way to trace out ...
7
votes
4answers
2k views

Is it safe to clean contacts with an eraser?

Today, while I was cleaning a RAM module, I was thinking about this. An eraser is really a easy way to clean gold/copper contacts in such modules. And it is really tempting to do so. I did it a few ...
2
votes
2answers
115 views

Computer Power Supply Testing Safety

I have a 750 watt ATX power supply that I will be testing with a multimeter to make sure the right voltages are present. How can I make sure that I do this safely? Is there anything that's threatening ...
2
votes
2answers
237 views

SG6841 based SMPS output droops on load

I am repairing an Elo Touch monitor ET1515L which, happily, has dual mains and 12V inputs. It works when powered from 12V supply but struggles on mains. I see sets of capacitors for the PSU board ...
2
votes
1answer
188 views

Can you identify this Bose car amp burned part? [closed]

Many more pictures here The radio and amp stopped working after a battery jumpstart. I fixed the radio by simply changing a fuse but the amp has a burned part. I tried contacting Bose to no avail. ...
0
votes
1answer
105 views

Is this board trace repairable? [closed]

The attached picture shows the main board of my Canon S110 camera. The camera was subjected to a shock with the USB cable connected. This resulted in the connector breaking loose from the board with ...
10
votes
3answers
932 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, ...
2
votes
1answer
786 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
152 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
2k 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
154 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
200 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
98 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
114 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 ...
2
votes
1answer
564 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
261 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 ...