I have a 2008 (Early) Mac Pro with a Nvidia GeForce 8800GT 512mb card.

It will no longer boot as it will freeze have way through...same in safe mode. I can boot into single user mode but not the with the CD.

However, before this happened, the screen flash quite a bit with lots of blue artifacts and sometimes, half the screen would go white. It then froze forcing the reboot. I did reseat the card and it boot fine but did it again in a few hours. I tried a different slot with no luck.

I did have a kernal panic about a month ago and the code was for Nvidia.

Is there a way I can test the card or something before I spend the $$$$$ for another card?