My PC has always suffered from this problem: upon reboot, the power, instead of staying up and running until BIOS POST, most of the time (but not always, and that's why I don't think this has never been the intended behavior) "cutted off" like it was shutting down instead of rebooting, before "starting up" again. Let's call this a "fake-shutdown". This has never been a big deal, so I never returned either the motherboard or the power supply.
But now this issue got worse, i.e. 90% of the time I'm totally unable to shutdown the PC at all. Meaning that both from
Ubuntu and from the BIOS Boot Menu, either shutting it down properly (from
Ubuntu) or pressing either the power button on the case or the power button on the motherboard (from both
Ubuntu and from the BIOS Boot Menu), the PC performs a "fake-shutdown" like described, but this time, leaving aside the weirdness of the thing, this is not even the intended behavior.
Surprisingly enough, disconnecting the power button on the case mitigates the issue, but doesn't remove it, i.e. the "fake-shutdown" still occurs upon reboot, even tough this happens let's say 20% of the time instead of 90% of the time.
My motherboard doesn't support Wake-On-Lan, and "Restore AC Power Loss" is set to
Power Off, anyway from the escalation of this problem I believe the issue is actually a faulty component's guilt, either the motherboard or the power supply.
So my request is this: can someone suggest a definitive test to spot which of the two is faulty? Or is there a third option?
As of now, only the DVD-ROM drive is connected to the motherboard.
Any help would be really appreciated and a good definitive solution/good definitive way to spot which is the faulty component will be rewarded as soon as i can put a bounty on this question, because it would be of great help both to avoid potentially wasting money replacing a random component and to avoid potentially wasting time without getting this fixed, since i really need this PC to be up and running.
Thanks in advance