Motherboard or PSU failure?

[Sweet Vandal]

Can someone help pinpoint my hardware failure?

The rig:

Windows 7 HP
I7-2600k @ stock (previously @ 4.2)
Corsair H80i
Asus P8P67 Deluxe
Corsair Vengeance 8GB RAM (4GB×2)
Msi Twin Frozr GTX580
EVGA GTX580
OCZ 1000w ZX PSU
120 GB OCZ Vertex SSD
320 GB WD Blue Caviar

The details:

Experiencing BSODs at irregular intervals, and without ever actually getting a blue screen or a reboot (while in Windows and in BIOS). My display goes blank and I get no response until after doing a hard reboot. Fans stay spinning, power LED stays solid, internal LEDs stay on, no sign of reboot or power issues. I don't have the equipment or a spare to test the PSU, but since everything stays powered, I'm skeptical that's the cause.

The times it crashes don't appear related - during games, at Windows login, web browsing, idle at desktop, idle in BIOS, etc.

Ran Windows Memory Diagnostic, came back with no errors. Was also going to try memtest, but alas, my rig crashed while formatting the USB.

I had my CPU overclocked to 4.2 ghz for a while, but rarely see temps go over 69 degrees under heavy loads, so I don't think that's hurt anything.

I'm suspecting the motherboard, but the diagnostic LEDs don't display anything, so I'm unsure of that as well.

Pretty much I'm hoping it to be something other than the PSU, but my main suspects would that or the mobo.

Any thoughts?

Edit - I initially recorded incorrect PSU information.

 

[alexoiu]

Same opinion: power supply or motherboard. Try RMA-ing the power supply (if still under warranty).