I have an HTPC build with an intel mini ITX mobo, sandy bridge i3, radeon 6770, 650W OCZ PSU, 8gb of Ram, in a Lian Li mini itx case.
About 6 months ago, the computer started turning off at random. I don't mean BSOD, I mean it just shuts off completely. Sometimes, it would automatically restart after staying off for 5-10 minutes. It usually happened while watching video with XBMC, but not always. It also happened sometimes when web browsing, etc.
I figured it was an overheating issue, so I ran temp programs, but both the CPU and GPU were running at low temps. Just to be sure, I rebuilt the entire computer, took out the GPU, reseated the cpu heatsink/fan with new thermal paste, and tried that. The problem still happened, and temps were low.
I thought it might be a bad PSU, so I got a new one of the same kind, and the problem still happens. I know I am not overloading my PSU. It is 650W, and shouldn't have any problems drawing/providing the power that it needs for my small system.
I thought it might be a windows issue, so I did a repair...no luck.
Lastly, I thought there might be a short. somewhere. I took all of the components out of the case, hooked everything up again on a piece of plywood with nothing touching, and it still happens.
I even disconnected all wires from the case buttons/LEDs, and it still happens.
I am at my wits end. Can anyone else think of anything that I should do, should check, etc to try and troubleshoot this?
Thanks for all of your help.