Don't trust any software-based voltage monitor - for instance sensorsd (linux) shows my CPU voltage at 2.05V
Usually if your PSU dies you wouldn't be able to play games for that long, or you'd start seeing parts die
permanently.
Before anything else, reset your CMOS and put GPUs to their default clock speeds - no use pulling your hair out trying to test unstable OCs.
Since your memory sounds OK, I'd look at the GPUs then the CPU first. Pick a GPU stress test (OCCT
Home or Furmark
FurMark: VGA Stress Test, Graphics Card and GPU Stability Test, Burn-in Test, OpenGL Benchmark and GPU Temperature | oZone3D.Net) and make sure you don't get either graphical issues or insane temperatures. I learned recently that an overheated CPU (in my case Phenom 9950 in my secondary computer) can actually cause the screen to go blank. Run a CPU stress test and again check the temperatures.