GTX 680 SC+ SLI not booting

[frozenn]

I just received my second gtx 680 today and once i installed it, the screen goes black right before it boots into windows and then restarts. ive tried both video cards by themselves and it works great. but it doesnt post once they are both installed. im not sure whatelse to do, ive checked all the settings in my BIOS and i cannot get it to post with both cards installed

850w corsairTX850
gigabyte z68x-ud3h-b3
evga gtx 680 sc+

ive tested both of the cards individually using both of the PCI-16X slots and they function perfectly, but when both are installed (with OR without SLI bridge) it doesnt boot into windows

 

[Commandermadi]

Make sure every thing is connected properly. The power connectors, the PCI-E Slots, etc.

 

[frozenn]

ive reinstalled the video cards and cables as well as tried both cards individually again. im pretty sure it's a problem with my power supply

 

[dingo07]

sounds like a motherboard issue

have you checked to make sure there's no dirt/dust/grime in the slots - a short is what it seems is happening somewhere

 

[regina_49]

I agree with Dingo07

 

[frozenn]

well thats unfortunate... im going to contact gigabyte then. If anyone else has any other suggestions im open to them! Thanks!