Questions tagged [failure-analysis]
The failure-analysis tag has no summary.
32 questions
3
votes
2
answers
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Components failure sensitive to temperature?
Some hardware of mine fails and then works, in a strange way.
I have to switch it on several times, (number of times looks like depending on room temperature).
Question is: what components (or (cold) ...
- 149
4
votes
3
answers
542
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Relay seeming to weld/unweld randomly (and continuing to click when "welded")
Main question :
I'm observing some very strange behavior on some relays (NO) on our PCBs:
the relay sometimes stays closed when I turn it off from software (as if it was welded closed)
but I still ...
- 9,688
9
votes
1
answer
626
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Toasted PCB region of power amplifier
I was going to replace a relay on an Alesis RA-150 stereo amplifier (a common failure mode) when I noticed some scorched 2W resistors (R401 and R402) and what appears to be an almost burned area of ...
- 263
4
votes
1
answer
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What is the most common CMOS failure mode in the wild?
When repairing electronic devices, I tend to see a significant bias toward modern CMOS ICs failing shorted to ground. In fact, I don't think I have ever seen a digital CMOS device that failed shorted ...
- 425
0
votes
2
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151
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After lightning and thunderstorm my STM32 chip got damaged [closed]
My STM32 breakout board was connected to a 15 V power supply which was then stepped down to 3.3 V by a buck converter.
After lightning and thunderstorm, the STM32 MCU got damaged but the buck ...
- 163
-2
votes
1
answer
238
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488 nm 30 mW 3.7 V laser: Is the driver or the diode fried at 9 V?
For a hobby project I'm doing, I accidentally gave my 488 nm 30 mW 3.7 V laser 9 V from a battery.
It appears to have died immediately.
Picture of similar laser (with housing) added for clarity. The ...
- 235
1
vote
1
answer
339
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Can an Hall effect sensor fail in a way that causes drift in the final measurement? [closed]
I am investigating the different failure modes of an Hall-effect sensor. The failure modes such as short or open circuit are easy to diagnose but I am not sure if the Hall-effect sensor can have a ...
18
votes
5
answers
3k
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What might cause these striations in this solder joint?
This is a 47 µF 1210 ceramic capacitor which failed. There is excessive leakage current through it and in the process of investigating, I found this unusual-looking solder joint:
We use a no-clean ...
- 35.9k
7
votes
3
answers
927
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N-MOS failing short on my PCB
I'm currently testing a PCB I designed. One of the MOSFETs, Q5, failed yesterday for the 3rd time, and I haven't managed yet to find out why.
Main facts:
N-channel MOSFET: CSD19538Q2T
Rated (never ...
- 9,688
7
votes
1
answer
392
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How can I verify or measure faulty (suspected cracked) capacitors?
I have some devices which operate at very low average currents of about 6 µA at 3 V DC. This is to ensure multiple years of battery life. However every now and then I encounter units which have ...
- 35.9k
1
vote
2
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115
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How to open hermetic TO packages?
I would like to open a TO-18 can to look at die-bonding/heatsinking and do some electrical experiments with increased airflow. Is there a non-destructive way to do this?
My only thought is to drill a ...
- 916
2
votes
1
answer
214
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SMPS Regulator keeps blowing
First Time for me posting here.
Recently I decided to perform a recap on an 20 y/o old SMPS, which is used in a digital mixer. The recap went without any complications. I followed the guide I found ...
- 61
9
votes
2
answers
1k
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Burned motor controllers: possible root causes analysis
On a submarine robot we built, during an operation, we recently had 3 defect thruster motors (the internal power PCBs have many burnt components, 2 of the motors cracked open due to internal pressure)....
- 9,688
11
votes
3
answers
3k
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Why did my LED drivers blow up?
I recently designed my first PCB, which houses LED driver circuitry for some custom lighting. I fastidiously followed the driver's datasheet (Diodes Inc AL8862QSP-13) in designing the circuit: making ...
- 119
5
votes
1
answer
486
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How common is it to receive PCBs with failed or weak vias?
This question is a follow up to Can chips be sensitive to mechanical stress after an electrical incident?. It turns out that our problem was nothing to do with failed chips. It was the PCBs all along.
...
- 28k