ATI Radeon 4870 Flash Problem

Hi there,

I have an ATI Radeon 4870 that came out of a Dell PC and I'm trying to flash it.

I believe that I successfully flashed the card but when I boot there is just a blank white screen and the OS does not start.

I'm on a mac 1,1 with 10.7.5 Lion installed.

Any ideas? Any help is appreciated.