New build booting problem

Hi, I recently purchased a couple of new computer parts and ive assembled everything, but im having issues booting the computer.

I have an ASUS P8Z68-V Pro 2 Radeons 6950's in cross fire 8 GB of DDR3 Gskillz ripjaw ram PSU CORSAIR| CMPSU-750HX 750W RT

When I tried booting the PC for the first time, the GPU's fans were spinning as well as the CPU fan and all that. The LED's blinked, with the DRAM LED staying on. Then, the computer would shut down automatically after 10 seconds, and then rebbot. After rebooting, it would stay on, but i still couldn't see anything on the screen.

I took out my 2 radeons and plugged my monitor on my motherboard's on another GPU. Still nothing. I'm pretty confused, as this is my first build.... I hope I didnt bend my Motherboard while trying to place my cpu fan, or that i didn't scratch it.....

Anyone has any ideas?