My rig runs perfect for a very very long time, no problems what so ever, then this morning it literally just turned off.
No blue screen, so windows shut down, as if it stopped receiving power and just turned off.
It wouldn't turn back on so i decided to pop it open real quick and see what was going on.
Plugged power cord in, waited for green light on mobo and gave it a few seconds and then hit the power button.
-Fans spin on for a second and i see a red light on the processor, its fan spun up for a second to, and then the fans stop and it wont even spin the fans on when i press the power button again.
-Only when i unplug and re-plug in the power cord will the fans spin up for a second.
The outlet, surge protector and power cord are all fine.
-So that leads me to believe it's the psu.
It has been pretty hot here lately in Vista California, that could be it. I have the 4 fans up at full all the time.
Sadly, could be almost anything: bad DIMM; motherboard; power connection. PSU would not be my first guess, but it is certainly possible. Motherboard manual is often helpful in these cases: take a look at beep codes and status LEDs.