PC hardware: Graphics card prevents computer from starting

Graphics card prevents computer from starting

I just bought several components to upgrade my computer. I had the case, motherboard, and DVD-RW drive from an Acer E700, and I purchased a 500 W Thermaltake power supply, 2 GB of Crucial Ballistix Tracers RAM, a Core 2 Duo E4600, an XFX 8800 GT Alpha Dog, and an 80 GB hard drive. All of the components seem to work except for the graphics card (meaning that when the graphics card is not inserted, the computer boots and works fine). Since the motherboard has an integrated graphics card as well, if the card is inserted, it still defaults to the itegrated graphics and doesn't output video through the XFX, even though the fan spins up and everything. Windows doesn't detect that the XFX has been inserted either. When I set the BIOS to force it to use the XFX, I get a continuous POST code which seems to consist of random, continuous, short beeps to my untrained ear, and it won't start. I've tried two different PSUs, to no avail. I've tried moving the RAM to different slots, reseating the graphics card, cycling the PSU, and clearing the CMOS (which I have to do anyway if I want to use the computer again, because that's the only way to get it to switch back to using the integrated graphics). None have worked. I plugged in the 6 pin connector to the card and everything. Is the card definately busted? Is there anything else I can do?