We had a previous board experience a similar issue around the capacitor directly opposite to the main power input, but this one seemingly happened without any possibility of shorts or anything touching the board. It was plugged in while being held by the main power wires and the pad beneath the ceramic capacitor ended up vaporizing as well. Wondering what could have been the cause and what nets are near this area of the PCB.
No, I meant the data transmitted by the unit at the time of failure. There are no internal logs stored in the device.
The PCB has nothing in this area but power traces, on all layers. It seems like the capacitor has encountered an internal failure, which could have been caused either by overvoltaging the unit or shorting the capacitor’s pins temporarily while the device is powered.
We have typically powered these units on 12S (~50V at full) but are now just running at 6S. Unless there’s some fatigue the capacitors have undergone due to this higher voltage I’m not aware of any other possibility besides maybe some freak ESD situation that shorts the power trace to ground.
These are high-quality 4.7 uF 100 V X7S capacitors from TDK. Peak 12 S voltages cannot cause degradation of these capacitors. Aside from what I listed earlier, another possible reason for the failure is a latent failure in the PCB, possibly caused by an earlier mechanical damage or a great thermal stress.
