Questions tagged [component-failure]
For questions about what causes components to fail, how to prevent component failure, and component failure modes (e.g. fail open or fail short).
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VDD and VSS pins shorted together
I have a PIC18F2420 MCU taken out of a PCB. There is a short between pins 8,19 and 20 which are VSS,VSS and VDD respectively.
Has this MCU completely failed?
One thing I have noticed when the MCU was ...
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3
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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 ...
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4
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PWM Dimming of a Low-Voltage DC Incandescent Filament (Thermal Shock?)
I plan on driving some Numitron tube filaments from an IV-16 tube (datasheet here). For ease of access I'll give the key specs here:
Nominal filament voltage: 3.15V
Max filament voltage (steady-state)...
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Swapping CANH and CANL kills my power converter
I got the first set of these CAN boards I designed and I plugged one into my test setup consisting of a two CAN dev boards as seen below. The first time I plugged my board in I didn't realize I had ...
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LM2576HVSX12NOPB blew up on 48V 10A PSU input
this is my schematic project for BLDC controller. the design have dc converter, mcu and gate driver. the dc converter is required to power the mcu and driver with 12 V and 5V. the problem is my dc ...
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Can diodes be tested successfully in situ? [closed]
I have tested a bunch of diodes in situ on a washing machine PCB. One comes back as expected with values of 0.6v and OL depending on testing direction. The rest show the same 0.6v in the expected ...
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Can a chip be damaged if it goes above operating temperature while running?
An image sensor I'm using has the following temperature spec:
Absolute Maximums:
Ambient storage Temperature Max: 125°C
Recommended Operating Conditions:
Stable image temperature Max: 50ºC
...
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What is this broken part/fuse?
This is a part that has been corroded from water contact. I appears to be a small connector with a ceramic base and two spade terminals. The wiring diagram for the item it's from identifies it as a ...
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2
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Power supply board failure: could it have been cause by a misoriented triac?
I have this power supply board from a Honeywell HPA300 air filter that has a burned out triac (BT3) in this row of 4 side by side triacs (...
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High frequency sound on a PWM fan for some specific duty settings
So I got a used fan (specifically a Sanyo Denki 9s1212 series) and I discovered that under most duty settings (practically when not 100% or 0%) the fan emits a high frequency sound like this: (mind ...
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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 ...
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MOSFET driver blows out in half-bridge DC motor PWM controller
EDIT: I've redone the MOSFET circuit diagram; it now represents what my actual layout is. I wanted to spare myself redrawing the circuit but ended up confusing everything, I hope it's clearer now!
...
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Need help finding specs for RV1 & RV2 varistors on fried board [closed]
Power surge blew 6 appliances and am hoping I can repair some of the boards. I cannot identify blow varistors in RV1 & RV2 positions on Saeco IG 1.9.168.00_V04 board. Any help would be appreciated!...
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Functional discrepancy within PCBA batch
When manufacturing a small prototype batch of an embedded system at EMS I have detected different behavior between the units. All units work as expected, except that some units fail to operate same ...
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How to design/build a relay-triggered "crowbar" circuit?
(This is a continuation of Failsafe for relay contact welding.)
I'm trying to wrap my head around something like a "crowbar" circuit, only, instead of tripping on over-voltage, it should ...
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What could have caused my power supply to fail?
I made a dual +/- 12 V power supply for synthesizer circuits using a schematic by Moritz Klein (image below). The input of the supply is from a 12 VAC transformer.
After soldering the circuit on a ...
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Failsafe circuit for a bistable latching solenoid
I am new to embedded circuits and working on a problem with which I need help.
I am using ESP32 soc for controlling a bistable valve using DRV8833 driver module. Please refer to this link for valve ...
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Help needed identifying SMD component (capacitor? power switching diode?)
Any help is appreciated!
I though it could be power switching diode but confused with no cathode marking or a capacitor. The device turns on intermittently (1 out 100 reset attempts).
Shape: ...
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Help with FBL Z803 chip identification
I have a component on my D5 EVO electric gate motor PCB which was shorting both ends to GND. This resulted in the PCB not powering on.
After removing this component the PCB now powers on, but part of ...
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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)....
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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 ...
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Mitigating FET current spikes in an SMPS buck converter
I'm currently designing an SMPS buck converter that converts 311VDC to 60VDC at 10 Amps maximum load. I'm using ESP32 for the PWM control, and IR2110 for the switching driver. The switch I'm currently ...
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Why did my IGBT die? What did I do wrong?
I was doing some experiments using the following IGBT:
https://www.pollin.de/productdownloads/D130905D.PDF
I used it to drive a load of ~4.7ish Ohm and ~140ish µH from a capacitor bank of 2350µF.
Each ...
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MOSFET failure in a high power AC-DC SMPS buck converter
I've made a AC-DC step down buck converter that converts 220 VAC to a variable 45 to 70 VDC at 5 to 10 A to charge a Li-Ion battery. I'm currently using ESP32 to drive a MOSFET driver (IR2110) to ...
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1
answer
105
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STM32f7G-DISC hardware failure during working on LCD
I was working on some function to view ADC values on an LCD, and suddenly the LCD went wrong and noisy. I felt the board's pwr pin_header was hot, also, after reset the problem persisted.
I've found ...
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1
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159
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Why are my IGBTs failing?
I am testing this H-Bridge circuit for driving a DC motor.
The Vdrive signal is a full wave rectified \$220 V_{RMS}\$, and I am using a PWM signal in the SD net to control the final voltage.
The motor ...
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1
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391
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Why might a 40 year old single chip processor have failed?
I've had a Fluke 8050A bench multimeter sitting on a shelf in my cold, damp garage for about 30 years. It was new in 1981, last powered up in the 1980s, and the display was dead. I came across these ...
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Electrolytic capacitor failure mode
In a project we're working on, we had an electrolytic capacitor explode on us. It was a surface mount device, UCM1H470MCL1GS from Nichicon:
So far, we've seen our project run for many hundreds of ...
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Which components can be labelled as "BD" on a printed circuit board?
In the process of repairing some consumer electronics, I encountered some SMDs labelled BD on the silkscreen:
As this one has clearly blown, I'm interested in ...
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DC-DC converter failure after adding a capacitor to the circuit
simulate this circuit – Schematic created using CircuitLab
The above schematic is used to heat a 2.4-ohm load. I am using a power supply from Meanwell GST280A24 280W at 24V. In the MCU it is ...
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4
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Did I kill my STM?
I have (had?) an STM32F429ZI. I was working with the ADC on PC0 and due to a hardware malfunction, 12V ran through the pin when the maximum voltage an ADC pin supports is 3V. Since then, whenever I ...
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What factors could have caused the ceramic capacitors on this board to crack?
While examining an old VGA card for faults under a microscope I found that all of the ceramic capacitors had cracked. The card is circa 1991 so it does have some age on it. But I wouldn't expect solid ...
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Why is only one channel of my dual H-bridge motor driver design failing?
I have a dual motor driver board I designed for driving 2 linear actuators with 48V and each one has as rated full load current of 3.5 amps. I can expect up to 10 amp short duration on startup, but ...
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Discolored negative lead on electrolytic capacitors
Would the discoloration around the negative lead of these capacitors be a sign of failure? If so, why would the negative lead darken instead of the positive - or both leads.
They are Maron EFM 35 ...
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Help fixing a power switch
While disassembling a Sega Saturn to clean it, I removed this power switch:
I needed to separate the top grey button (1 in the image) from the rest of the switch.
After verifying with a multimeter ...
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Failure mode of two series LEDs
I have an "interesting" circuit failure. The circuit basically looks like
simulate this circuit – Schematic created using CircuitLab
The left branch works perfectly fine. The right ...
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Have my LEDs failed over time?
I installed 6 battery-powered 1Watt LEDS in my dad's home to help when he has power outages. They worked as intended for some time, but recently begun to fail in an odd way. They no longer turn on ...
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4
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Calculation of Junction Temperature
I have a PCB and trying to measure the maximum junction temperatures of the major components in the PCB which in full working mode. For example like Input Diodes, Buck Regulator ICs, Aluminium ...
user220456
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4
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4k
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Schottky diode failure
TLDR:
What are possible failure sources for a schottky diode? Overheating, overvoltage, overcurrent (leading to overheating) anything else?
Long version
I am currently measuring our new prototype ...
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Potentially unusual LED failure
One of the LEDs in a plug equipped with over-voltage protection does not light up when the device is plugged into the 230 V mains. It has worked well for a while since the product was purchased. An ...
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2
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Op-amp failure and prevention
simulate this circuit – Schematic created using CircuitLab
I'm a programmer and self-taught digital designer, and I thought I could deal with an op-amp even though I haven't for over 20 years.
...
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Is is possible to calculate the MTBF or Failure rate from a given datasheet when manufacturer have not given these details?
As there are new components getting added to the mouser or digikey, is it possible to calculate the failure rate based on some pre known facts and values? some vendors don't reply for weeks and I can'...
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Data errors from network device at high ambient temperature(60C)
I have a Raspberry Pi Compute Module 3 based network device that I am trying to get working at high ambient temperatures (up to 60C). When I run TCP packets through the device, I get checksum errors ...
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Suitable Replacement for a Dual Coil Latching Relay
After questioning about my broken thermostat there Debugging an old Thermostat: What component is this? (3 pins SMD IC), thanks to @JRE I could find that it was actually the relay on the board that ...
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2
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958
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Debugging an old Thermostat: What component is this? (3 pins SMD IC)
My Thermostat stopped working a couple of days ago and I tried to debug it.
The first thing I check is if there is any component that gives a strange result with the multimeter and I found these ...
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262
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How to read different IV charts in the "component tester"?
I am doing a "comparison test" of 2 cards with the component tester. My component tester has 4 different test modes. LOGIC, LOW, MED and HIGH. LOGIC (10V 10mA), LOW (10V 100mA), MED (20V 5mA) and HIGH ...
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What is the failure rate for PV string blocking diodes?
PV generators do often contain low voltage bypass diodes at module level, and less frequent high voltage string blocking diodes. Example of such blocking diodes are the Ixys DNA30E2200P (VRRM = 2200V) ...
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Performance changes to metal can transistors installed 40 years ago
What problems, if any, are to be expected when using 2N4037 metal can PNP transistors that were installed 40 years ago?
I can't divulge much about the design, but transistors are in a voltage ...
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5k
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MTBF / MTTF and parallel systems
I'm doing an MTBF calculation for a system. Basically I calculated or searched for the MTBFs / FITs of every component. Then added up the FITs and got the total MTBF.
My first question would be the ...
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Can failure of an old electrolytic capacitor be precipitated by motion?
I have report of a circuit board failure. The board was 20+ years old, and included at least one electrolytic capacitor. That capacitor would then be beyond its expected useful life. The board was ...
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