AGP X1650 Pro no post, no beeps

I upgraded my Geforce4 4200ti to a X1650 pro with no initial problems. I ended up keeping my computer on for a good 3 weeks then finally turned it off, but when i powered it back on the bios did not post. All fans would turn on, hard drives turned on, but no post or beeps. I got error beeps when taking out ram or the video card so i cancelled out my motherboard as being the problem. Also i tried clearing the CMOS with no success. So i put my older video card back in and the computer booted up fine. This lead me to believe it was a PSU issue so i upgraded my PSU but now even with the new power supply its not posting.

CPU: Athlon XP 2500+ Barton
Mobo: Abit NF7-S v2.0

PSU Specs:
Corsair VX450w
+3.3V::20A
+5V::20A
+12V::33A

Currently i only have the video card hooked up via 4-pin connector with no other peripherals hooked up to the power. The fan on the video card still turns so it is getting power.

Any advice is greatly appreciated

Well the X1650 Pro did work before with my older psu. The reason i thought it was the psu was that it wasn't running much power on the +12V rail, and also its about 9 years old. So the only thing i could think of was that it couldn't handle the constant strain of the new video card.

What would cause the card to become defective?

Sounds like you need to RMA that sucker. Try to check it in another computer to be sure though.