UD5H Wont boot

[InsanitysFall]

So today i recieved all the parts for my brothers pc build and when i assembled everything on the motherboard box and pressed the power button the power light stays on, the debug code light flashes on then off, and my m-bios and b-bios lights are flashing. All the fans turn on, gpu fans are spinning but i have no output going to the monitor.

I'm lost, i've tried changing the bios, using a single stick of ram, switching the ram slots, removing the c-mos battery. Any ideas?

specs of the pc are

i5-3570k
gigabyte ud5h
corsair vengeance ddr3 8gb
noctua nh-d14
gigabyte gtx 670
samsung 830m ssd (i think. cant remmber the exact model)
corsair hx650 psu

 

[Goldskis45]

One thing I caught myself with on a recent build that acted similar, was I had a pci-e plug in the CPU power slot and it did just about the same... (pos an neg are backwards)... Took me an hour of deconstructing and head scratching to notice...

 

[InsanitysFall]

It's definitely the 4+4 power cable plugged into the cpu. Thanks for the advice tho.