My home PC is showing very strange behaviour since last Friday. Said behaviour shows as follows:

• PC will "reboot" suddenly. No simmilarities in terms of time, Core or ambient temperature, or memory usage.
• Said "reboot" leaves me with a blank screen, no BIOS beep or anything
• Doing a cold-start sometimes works, sometimes not. Again, no correlation to temperature could be found. Having the computer running for some time in blank screen mode does have no measurable effect, as does just having power go to the PSU without the PC itself running

Things tried so far:

• Disconnecting all components (even RAM) and reconnecting one by one: worked once, didn't work the second time
• Testing the RAM-banks one by one: no change
• Running a stress test on CPU and memory: nothing peculiar, could use the PC for about 4 hours afterwards before it "rebooted" again

My current guess would be either a defect BIOS-chip or a defect frequency generator for the CPU, as both would explain why it wouldn't even show the BIOS.

TIA
/darthludi