I purchased a new card because the 8800 gt stopped functioning well after 2 years--every time I booted I would get to the boot screen and there would be artifacting and screen tears all over the place, and I wouldn't be able to advance past that screen.
I just received the 5770 several hours ago and after installing it, I cannot even get as far as the boot screen. The monitor has no input, as if it were not connected to anything. There is not even a black screen, just no video output whatsoever.
There is no beeping, I don't hear the card's fan, I've tried 3 different expansion ports and made sure it was seated deeply. I've power cycled close to a dozen times now. When I put the old card back in, at least I get to the fubar screen, but with this new card, I can't even get that far.
The power supply should be sufficient, and I made sure that the card was plugged in using the 6-pin connector, which was the only one that appeared to needed to be plugged.
What should I do? I ordered from NewEgg, is the card just DOA?
Edit: It's also worth noting that I am dualbooting OSX/W7
no ***, but it doesnt work with 2 SEPARATE graphics cards. it doesnt work with the 8800 and it doesnt work with a 5770. Maybe your motherboard is fried, maybe your PSU is no good, maybe you got a dud 5770, maybe its just not compatable. I would vote for the 5770 not compatable and would suggest you should swap it for a gts450. You have a mac, macs arent really meant to be upgraded, apple arent friendly in this way. When people are done with them they get a new one and talk about how pretty it is and how it can run one particular program that windows cant run (yet they forget windows can run a million that mac cant run) /rant