Question PC starting stopping with RAM installed

Dec 10, 2019
A couple days ago, the PSU of my PC started making a horrible noise when my mom was using it(just after she swatted a fly on the case) so she switched the PC off. When I tried to next start it, it would start, run for a few seconds, get the cpu fan spinning, then stop, restart and repeat.

At first I thought it was the PSU, so I got out my multimeter and checked. It had all the right volts in all the right places. However, I took it into the PC repair shop all the same and the guy plugged my PSU into the store PC and it did the same thing, then said that the PSU was done(he used slightly more colorful language).

OK, fine, so I bought a new one. While I was at it I bought 4gb new RAM for my pc. I came home, put in the new PSU and the new RAM, tried to start it, same thing. I then removed all my RAM, and it runs fine. I put in the old RAM, it does the few seconds run and restart. I put in the new RAM next to it and it runs for 10/15 seconds before restarting. I took out the old RAM and it runs for 10 seconds before restarting.

The only thing I can think of is that the mother board is done, but what confuses me so is that the old PSU did the same thing in the shops computer as it did in mine. Could it have been both mother board and PSU at the same time? Seems really unlikely to me.

Another question, if I may. I live in South Africa and we are currently going through heavy duty "Load Shedding". Our power supply is unable to match the demand, so they switch off various municipalities for a number of hours everyday (up to 12 hours right now), and what often happens is that a phase of power is turned off. If we have only single power phase working compared to 2 or 3, could that be the problem? Thanks for the help in advance.