could also be a power problem. do you have a UPS? surge protector?
Tried the UPS, the computer shut down within minutes of booting.
Asus boards do have a tendency to read voltages wrong. Not saying that it couldn't be correct. I would test the 12V with a DMM before I suspected too high of voltage. My M3A76-CM read 11.3V, but my multimeter (read AT the motherboard and GPU) showed 12.6V.
Try cleaning the entire case out. Taking EVERYTHING out. My computer was shutting down at random times because of a faulty motherboard riser, and causing it to short when the PSU wires were pressing on the motherboard.
Ok, pulled everything out of the case and it still happens. Looks like it's back to the drawing board.