Electric company plugged in some device to measure power over time. Turns out the power was slightly below normal but within tollerances. The OEM power supply that was powering my Atari wasn't up to standards. If I remember right, badly designed PSU's can feed too high current if the voltage is too low. Or something like that, was a very long time ago...
We have so many cheap power supplies in our houses that it would not surprise me if at least some become unsafe if the source voltage drops too low. Being unsafe with only a slight drop is weird though.
My experience is always replace DRAM, and then PSU, and then Swap Motherboard.
I don't think people realise how many faults there are with DRAM, PSU and MB. DRAM quality has gotten a lot better in the past 10 years so that is less of an issue. PSU, however it where cost cutting are and more often than not causes problems.
Google's definition of a server was (and still is afaik) based on the tray (chassis) so there was no way to replace it. IIRC it was "retired" with vengeance leaving a gap in the cabinet — a warning to other trays to behave.
Used to work in PC repair. Man brings in PC, mouse right click doesn't work. Everything else operates perfectly.
Replaced in this order: mouse, IO card, hard drive with fresh OS, RAM, CPU, graphics card, motherboard. Still no right-click.
Replaced the PSU last. Right-click works. FML.