I have a msi p55-gd55, a dark power 650 PSU, i5-750 with some ram and a gfx card. Its been fine for a good few weeks until late last night. I was browsing (hardly any cpu load) then I hear a hiss /swoosh sound (like the kind of sound when a cable touches a fan) then the machine powered off. When I press the power button the mobo blinks its onboard LED and spins the cpu fan for 0.5 second then goes off. I guess its the psu, but I dont have another spare that fits my motherboard. I guess im going to have to pop over my mates on the weekend and borrow his. Now I am guessing it is the PSU, but are there any hints it could be the mobo? Just want to explorer a few things before the weekend arrives.