New GTX 980 Ti graphics card not working.

Hi, could use some advice. I just bought an Asus GTX 980 Ti to replace my GTX 580. When I turn my PC on, the lights and fans on the 980 Ti turn on, but I don't get any video on the monitor. Eventually, the fans on the card stop and my motherboard gives me a single beep every 10 seconds or so.

I called Asus tech support but they didn't do any troubleshooting. I told him I had a Corsair HX850 PSU and he immediately said my PSU was too small. I can't imagine that is the case. I put my 580 back in and it boots fine. My PC specs are intel i7 2600k stock speed, Asus p8z68-v pro\gen3, 16gb RAM, Corsair H80i cooler, 3 hard drives, and 1 SSD.

I plugged in both 8-pin power connectors. There was a small red light above each on the 980 Ti that turned white when I plugged them in.

Anyone have any ideas what could be the problem?