New Motherboard won't power up with GPU installed

[airewalker]

Hi guys!
I just attempted my first motherboard/CPU upgrade, but I've run into a problem.
First, here's my setup:

Intel i5 3570K processor w/ stock cooler
Gigabyte Z77X-UD-3H motherboard
8Gb DDR3-1600 RAM
HIS Radeon 7970 Video card
Cooler Master 850W PSU

I installed everything, plugged everything in, and when I went to turn it on, nothing happened. The light for the mobo mounted power button turned on, but thats it. No fans, no beeps.

I went through the troubleshooting guide, and found that after I took the video card out, the system powered up no problem. I put the video card in again, no power.

Is there a solution for this? Is it a bad PCIe slot? Do I need to update the BIOS?

Any help you can give would be much appreciated!

 

[airewalker]

Quick Update:
Without the GPU, I was able to log into Windows and install the chipset drivers. Computer works perfectly without the video card, but...

If I install the video card, I get the same problem, no power. I tried with my older GTS 250 video card installed, and it worked!

I did have trouble getting the 4+4 power cable inserted on the Radeon card. I wonder if something went wrong or broke there. Or, am I inserting the wrong power cable? The Radeon card has an 8 pin and 6 pin connection. I've been inserting the second 4+4 cable from the PSU, it's the same as the CPU power plug. Should I be using one of the modular 6+2 cables in the 8 pin slot?

 

[airewalker]

Solved!
4+4 power cable to the 8 pin slot was the problem. Tried the 6+2 and I'm back in business.

Funny how typing out the problem helps to solve it...

 

[Dark Lord of Tech]

This topic has been closed by Area51reopened

 

[Dark Lord of Tech]

Best answer selected by Area51reopened.