DFI Lanparty NFII Ultra B problem...

First things first, im an experianced computer builder so please dont
suggest anything as simple as "check for short circuiting" and the like.
Okay...

The Problem....
After pressing the power button on my computer (to turn it on. I was
rather unamused when the ass at DFI support thought i ment when the
computer was already turned on) it powers down 3 seconds later...

What I've attempted
Tried 3 different power supplies, no effect
Tired a different CPU still no effect
Tried different RAM no effect including different speed and size
Tried removing all IDE devices, still no effect
Tried removing all PCI and AGP cards, no effect
Tried resetting the CMOS no effect

Points to note
When CPU is removed the motherboard powers up properly
This is a replacement motherboard from my supplier since my last one
failed on me for no reason so its total runtime is nill
There are no signs of physical damage to the motherboard.
There is no error beeping at all

Any ideas that i might try or check for would be great, >>excluding<<
returning it.

Thanks

 

Ok. So you don't need help, then. That's good.

 

Gosh-a-mighty, I wonder if there could be a clue here somewhere. "When
CPU is removed the motherboard powers up properly".....

 

Okay, a simple suggestion - RMA