I have an old Windows XP desktop that decided to die a little while back when the machine was rebooted following a Windows update. During shutdown for reboot the PSU powered off and will not power on again. Press the power button and the fans spin briefly but nothing else happens. No power, no beeps, nothing. Disconnected all hardware, except motherboard & PSU, still nothing.
I put in a replacement PSU, and the computer boots up fine, and runs Windows no problem. Another update came in and it requested a reboot. Again during shutdown, the PSU powered off and is now dead in exactly the same way. Different model and brand PSU.
I've followed the PSU instructions about overload/shorting issues, i.e. by disconnecting mains power, wait a few minutes, reconnect and try powering on, but nothing.
I have also tried a further PSU but only going as far as the BIOS screen. This works fine, and is not harmed if I manually shut the computer down by holding in the power switch. I don't want to let it boot into Windows in case it is also killed though.
I've gone through all the cables to ensure they are not damaged and connected fine, and checked for anything that may be shorting out. Also, when this initially happened there were no hardware changes. This desktop has been running fine for years without changes made to it.
Has anyone heard of something like this before and what it could be? I suspect something is shorting during power down (disc spin down perhaps?).
I can provide a full PC spec if needed, but have left it out to avoid clutter for now.
It's an old PC and I intend to just replace it anyway, but I want to re-use the discs at least briefly to transfer data and concerned that a drive might be frying the PSU. Unless anyone has other ideas?