computer turns on and then immediately off

[compEngineer0]

just built a new system, 370 watt psu. all was working great for like 2 days continuously and then came home and found it turned off. so i turned it back on and it immediatly turned back off, before monitor lit up or bios appeared. normally i would think overheating or bad psu, but it was running great continuously for 2 days! any ideas?

[GX1_Man]

I think your diagnoses are the most likely. Try reseating every component and try it again. Do you have another working power supply you could test with after that?

[Raptor]

A fan could have failed in the meantime.

Inspect all hardware.

[compEngineer0]

it seems to be working again now so i'm gonna watch it in the mean time. all the fans appear operational. i'm tempted to rule out overheating b/c if that were the case then i think playing processor intensive games like doom 3 and what not would kill it rather than idle. as for psu, its an antec truepower which i believe are reliable, but i'm not ruling that out yet. if it dies again i'll try a new psu. if any other ideas... let me know! thanks!

[Computer_Commando]

Could be a power brownout in your area.