My system seems to crash from time to time. I still don’t know what causes it.
If I leave it untouched for a few hours, sometimes, it crashes.
To resume, I have to force a reboot by unplugging the power cable (not even pressing the power button for N seconds seems to work).
Then, it seems to work just fine (after displaying some error messages about lost or orphaned inodes at boot). Until, one day, it happens again. When? I never know. It seems to follow some strange and unpredictable pattern.
Where should I start investigating?
Something like a hard drive could generate recognizable errors in the logs, but once you get out into the motherboard or power supply, there’s simply not enough monitoring available to detect problems. You might be able to record the voltage output from the power supply rails, depending on your hardware, but that still might not tell you anything.