When I disconnect the power from the card, I am able to get a video signal. When connected, I am not.
So is my Antec PSU not powerful enough to handle my card? From their website for my PSU: PCI-E connector: one for 380W and 430W, two for 500W. All in all, that PSU is a nasty Medusa of a power source, I've never seen so many wires from a PSU.
I'm looking at the 6 pin connectors, and there isn't really an indication of which one is which.
Added from some stuff I saw at Newegg: An important tip from one of our users: don't just check total power output, find out what you need in the way of current on each power rail. If you need 20 A on your +12V rails and the supply only has 15A, it doesn't matter how many watts the supply puts out: don't buy it. Make certain that you have ENOUGH rails, too: sometimes, you need more than just two +12V rails for your setup.
^ Can someone with more technical knowledge than me translate this into layman's terms?