So I'm going to start from the very beginning explaining this. After my computer was finally built, sometimes we would have to do this trick where we would have to turn off the power, hold the power button down for 1 minute and then turn power back on and only then the computer would start. I'm just putting this in there if someone can connect it to the problem I'm having now.
So the problem I'm having started 1 week after the computer was built. At random times, the whole system would cut, and then after 3 or 4 seconds the power would return to the computer and everything would turn back on again. I managed to fix this for about a month by unplugging the system from my surge protector and plugging it into the wall socket. This seemed to fix it for a month but now the problem is back.
I have a feeling the problem is hardware because once I get a reboot, I get more that happen few minutes after. It also happens sometimes before windows has even booted.
What I've tried: I've run memtest for 4 passes, no errors. I've run stress tests on the CPU and the system stayed stable. I've run stress tests on the GPU and the system stayed stable. I've taken out the RESET SW wire, but it didn't work.
My educated guess would be that it's the PSU acting up, but before I RMA it I want to know why I was able to fix it for a month by plugging it into the wall socket, and why it's now come back.
I5 4670k @ 3.4ghz
XFX 650W Bronze Edition PSU
Cooler Master Hyper 212 Evo
Asus Z87 Plus
Any help would be greatly appreciated because I am stumped.