GTX 690 SLI not working. Please help

[PSOstrife2000]

Hello! I just finished building a new custom PC. Everything worked fine with 1 GTX 690. But when I put the 2nd card in it would show the mobo screen when I turned it on. Then just a black screen. I plugged them into PCIex16-1 and 2 slots. I have tried 2 different bridges and flipped them both ways. Both cards work on there own. Here are my PC specs.

Gigabyte GA 990 FXA UD7 mobo
Dual Nvidia Geforce GTX 690 ASUS bid cards
AMD FX 8350 Vishera CPU
32gigs ripjaw gskill x ram
Cooler master silent gold pro 1200w psu
Kingston hyper x 250gig SSD

Thanks for the help!

Also I have tried every power cable variation. And tried every configuration for each card alone in every slot. My mobo does support sli. I just can't seem to get it to work with both cards in.
Is it possible I'm not plugging them into the right set of PCIe slots?

[autotech]

Welcome to the Gigabyte Forum. I was waiting on someone that owned this board and use SLI to post but it hasnt happened after reading the manual PCI-E slots 1 and 2 can run SLI at 16x i did find a note on website to update to latest bios. I have had 2 cards run fine by themselves and not in SLI  i finally sent them back and exchaged them for two different cards telling them what my problem was and the two cards i got back worked.

Not sure if that is your case or not but it is just something that i had run into before. Below is an excerpt form Gigabytes site.

Flexible graphics capabilities - Up to 4 VGA cards are supported for either 4 way CrossFireX™ or 4 way SLI™ action (running at two x16 or four x8 bandwidth), delivering the ultimate in graphics performance for gaming enthusiasts who demand the highest frame rates without compromising on resolution.
Note: Please update the latest version of BIOS from GIGABYTE website and VGA driver from vender’s website.