New Build Power Cycling?

xTechBeast91x

Honorable
Oct 1, 2012
35
0
10,540
Hello, I have recently built a new computer, and when I put everything in, the system power cycles. I can't figure out why. I eliminated the fact that the psu is dead because i used it with another pc, all the cables are snugly plugged in, I used standoffs, I cleared CMOS, put only one stick of ram in, put no ram in. Nothing works. I think the motherboard may be DOA but I want to know for sure.
My Build:

Core i5-3570k
Maximus V Formula Z77
H100i
GTX 680
Thermaltake Black Widow 850W PSU
 
This may be obvious but are all the power plugs on the motherboard connected to the PSU?

1 x 24-pin EATX Power connector(s)
1 x 8-pin ATX 12V Power connector(s)
1 x 4-pin ATX 12V Power connector(s)

 
I really don't wanna have to rma, but I need to know in 2 days if I have to RMA the motherboard. I've unplugged everything from the motherboard and put a fan in to see if the fan spins when it turns on, and it does. But then it stops after 6 seconds. It should stay on, even if not everything is plugged in, but it doesn't. I tried two different PSUs and neither worked. It stays on for about 6 seconds and then turns off