Question PC is restarting randomly … but I think I’ve eliminated all components as the problem!

Jun 18, 2022
Thank you, in advance, to whichever hero can help me get my head around this …

A few years ago I was gifted a beautiful custom built PC. It served me well for some time, mostly as a home server (pun intended) and some gaming.

Seemingly at random, some time last year it began occasionally randomly restarting.

Almost exactly at New Year’s, the restart cycle became incredibly rapid, and eventually it failed to boot completely.

After a lot of testing, reading and more testing, I confirmed that the motherboard had failed. I took the plunge and replaced it with an MSI B560M Mortar and an i3 10105F. Everything booted and everything was superb for many months.

Unfortunately, the random restarts came back. Occasionally at first. I know the previous mobo had definitely failed and concluded (I think accurately?) that there must be another problem with another component that both causes the restarts AND caused the mobo to fail six months ago.

However … after the following, I can’t for the life of me see what component that could possibly be:
  • I’ve run the system with all four RAM chips individually and the issue still happens
  • I’ve taken out the graphics card (GTX 1070 Armor) and run the system headless … still happens
  • I’ve detached all internal drives except the SATA M2 on which Windows runs … still happens
  • I’ve booted Memtest from a USB stick so the M2 C Drive was not booted or engaged at all, which makes me think it’s neither a software installation problem or a problem with the SSD itself
  • I have completely replaced the PSU with a new one
  • I’ve done my best to scour the logs for any clues, but there’s nothing until a critical error is registered on startup noting that the system didn’t shut down correctly
  • I’ve cleaned the chassis and fans, and also kept an eye on the temperature sensors I can find, and all seems well — I also left the system off for several hours with an external room fan helping it cool down completely, booted it, and had a random restart within two minutes, so I don’t think it’s an overheating issue.
I’m left wondering if it’s one of the following:
  • Dodgy case somehow (is that even possible?)
  • Dodgy fan or fans somehow (seems even less possible)
  • The SSD is faulty and affecting the system even when it’s not booted or engaged (which I’m suspicious of because this still happened when Memtest ran, with nothing going to or from the SSD)
  • Something else I’m not clever enough to know
  • An ancient curse on my family.
Once again, enormous thanks in advance to anyone who’s even read this and can offer any suggestions!
Jun 18, 2022
For whoever finds this later …

yes, it is possible for the case to be dodgy!

It was my reset button. My reset button was faulty and causing random restarts. I hadn’t even realised I have a reset button. Disconnected it and all is well.

Can’t believe it!!!