Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [failure]

189 questions
54
votes
13 answers

What kind of components in a computer power supply can explode loudly?

Today I heard a loud bang that tripped the circuit breaker in my server room. It must have been really loud because I could hear it 2 rooms away through 2 heavy doors and it was like a firecracker going off right next to me. Long story short, it…
user81993
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Why would a buck converter IC fail and blow up?

I have a deployed design in which we are experiencing a high (~4%) failure rate in the 12V to 5V step-down buck converter portion of the PCB. The buck converter's role in the circuit is to step down 12 V input (from a connected lead acid battery)…
macdonaldtomw
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6 answers

Could a modified sine wave inverter destroy/damage the AC adapter for a laptop?

I recently encountered a scenario where I attempted to use a Energizer EN500 modified sine wave inverter to provide power to a Dell 180 watt AC adapter. The circuit powering the inverter was 12 volt, 15 amps DC. The AC adapter input is 100-240V ~…
Josh
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Puff of smoke in air. 3 different PCBs. PCB has ghosts?

Yes, that is a haiku.  (EDIT: fixed it... it is now actually a Haiku) No I'm not smiling. I'm doing some standard testing; seeing what happens when one of the two power rails gets shorted to GND on a PCB that I designed.  We're talking about a 12 V…
macdonaldtomw
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16
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3 answers

Do MOSFETs usually burn open or closed?

I was wondering if a power MOSFET fails due to overheating, will it usually burn as an open-circuit or short-circuit? Also, does over-temp damage usually cause the gate oxide to blow through as a low resistance ( < 100 Ohms)?
Adam
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4 answers

What is the minimum temperature for FR-4 PCBs?

My company is working on developing a product that will go into commercial freezers, so my boss asked me to provide operating temperature specifications for the product. I can find "operating range" temperatures listed for everything but the PCB…
TimH - Codidact
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4 answers

What causes loss of power over lifetime of a magnetron?

The power of a magnetron declines over time\$^1\$. While not noticable for most consumer applications (A 2000-hour lifetime would last over 20 years if the device is used only 15 minutes a day), this is a problem in industrial situations. What…
Joren Vaes
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7 answers

What caused this IGBT failure?

I connected the circuit below, a transistorized ignition circuit, and it worked for a couple minutes, then it stopped working (engine quit, wouldn't restart). When it stopped working, I couldn't feel anything that had clearly overheated on the…
Bob
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8 answers

Detecting stalled AC fan in high-temperature system

The problem: AC 230 VAC fans in a system rated to 100 °C need to be monitored for failure. There is no third wire, just the L and N leads. None of the potential solutions seem good. For example: Optical coupler of some kind Hall sensor near…
Dirk Bruere
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How do ADCs fail?

I'm responsible for maintaining a satellite that has an ADC that is failing in an unusual manner. Essentially what is happening is that it toggles back and forth between two values, if the raw voltage is in a certain range. I'm working on getting…
PearsonArtPhoto
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3 answers

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 sure the inductor, capacitor, current sense…
Reid
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4 answers

My PCBs etch all bad! (sodium persulfate)

I've recently started having problems with etching my PCBs. I use a permanent marker to do the traces and etch them in a stainless steel cup, heated with a tea light (small candle.) The PCBs come out very badly, the traces have holes in them and…
thegamebusterpl
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4 answers

Reliability and failure mode of MLCC (chip capacitors)

Recently I've been preparing to manufacture a product which exclusively uses MLCC capacitors across the board. It integrates an onboard buck converter which uses them, and MLCC are also used for local decoupling. My prototypes have consisted of…
Thomas O
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4 answers

AVR flash memory corruption

This question is related to AVR deprogramming itself. Project info: We have a battery powered product using an ATMEGA644P. The application permanently runs in sleep mode and only wakes up once a second (RTC) or when one of the two external…
Rev
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1 answer

What effect does Gamma radiation sterilisation have on embedded electronics devices

We just received back 3 pieces of equipment that may have been inadvertently put through a Gamma radiation sterilisation process. The equipment is a low-power embedded device consisting of a 16 bit microcontroller with peripheral FLASH memory and…
geometrikal
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