No POST after installing new 8800 GTX

Specs: Core 2 Duo CPU, Gigabyte ga-965p-ds3 MB, Silverstone Decathlon 750W PSU, 2 GiB RAM.

After putting this all together, the computer is not POSTing. There's definitely a video signal, but the screen is blank. I returned the card to the manufacturer some time ago, but they said that it was working fine on their test system. The PSU should be enough power for the card. The first time I installed it, the video card put out the infamous "banshee scream from the pits of hell" that comes from it not getting enough power, but it went away after I reseated the card.

The computer will POST perfectly fine if I remove the card and hook up my monitor to the integrated graphics.

No I did not. The motherboard manual stated that the default setting should automatically detect the PCI-E card and output video through it if present, but I haven't actually checked the BIOS itself.

Did you connect the two auxiliary power connectors to the 8800GTX?

Actually, never mind. It was something incredibly stupid. (The DVI-to-VGA converter was bad. )

I just assumed it was something wrong with the card since I've been having various other troubles for the past 2 months with it (related to power supplies).

Anyway, thanks for taking the time to respond.