The build:
http://uk.pcpartpicker.com/p/MNgNxrSeemed fine yesterday, downloaded LoL, DOTA, played games, everything was dandy. All of a sudden when just using chrome it shut off.
Unplugged it overnight to let capacitors or whatever discharge, took it apart this morning, checked the motherboard standoffs were all fine and everything was actually plugged in properly and put it back together, worked fine.
Was on for about 5 hours, the last 2 or 3 playing DOTA 2, when after a game it suddenly turned off - kinda.
The monitor said "no signal" and the LED went off. As far as I could tell the GPU and CPU fans were off, but the case fans were still on. At a loss for what could be happening now.
Oh and if it's relevant I've not fiddled with any BIOS stuff or anything like that, all still on defaults.
Optical drive light flashes and can open. Mouse lights up.