I've had systems that would work fine for a while, the refuse too boot until they were completely powered down for a singificant period of time (12-48 hours). In each case it was a damaged motherboard.
For three boards to be damaged in such a way quickly, the PSU would almost certainly have to be the issue.
I suspect your PSU is defective, or you have some other serious electrical issue (bad grounding maybe).
Originally Posted by HiroPro
I have never in my life seem RAM that can do 1866 at 1.5v ! Amazing if it actually works at that speed with only 1.5v IMHO. Bump your RAM voltage to 1.6 and see if it help... and hey sorry for the attitude it's just I had a shop at one point and people like this guy and others that post here with 3 plus returns thinking it's the hardware over and over again really piss me off as it's totally THEM and their lack of understanding and nothing to do with the hardware.
JEDEC validated DDR3 1866 and 2133 not long ago, and plenty of recent memory can work at 1866 with only 1.5v, there is even 1.5v DDR3-2133 and 1.2-1.35v DDR3-1866 and 2133 aren't far off.