Random Shut downs

[DEF Hater]

I just built a new computer and I am having random shut downs. I believe the problem is the psu but I want to know if anyone has other ideas. I ran prime95 for about an hour and as soon as I hit stop test, the computer shutoff and immediately restarted. There was no blue screen. Other times the computer could just be idling and it will shut off with out a blue screen. The last odd bit is if I tell the computer to shut down, it will shut down then turn itself back on a few seconds later.

Possibly bad psu or a short somewhere?

Celeron G1610
Asrock H61M-DGS
Corsair Dominator 1600 RAM running @ 1066 and 1.5v
Intel G2 160gb ssd
Seagate 1tb HDD
OCZ 1000watt psu
Windows 8 64bit
BitFenix Shinobi case

I threw this computer together from spare parts if that isn't obvious.

 

[Dangman]

Run Memtest
Try a different PSU.

 

[DEF Hater]

It was the super awesome OCZ psu. Now have a Corsair in there and everything is perfect.

 

[Britgeezer]

Yes I would have said look at PSU and consider Corsair / Seasonic.

Glad its solved.