Don't know the answer but really are anxious to hear the answers.
I have maybe the same problem with my son's pc. Got it second hand, put a gt330 in it. Thought allreday it was broken, when i booted i got a long sets of ticking sounds and after a while it switched to the on board. Worked a while in windows, than restarted with the bad gpu in it so i could have a look at my bios. Got in Bios for a sec or 5 than the picture got completely teared and unreadable and after that no picture anymore even if i reboot.