I have an early 2009 Mac Pro with a stock ATI Radeon HD 4870 512 MB Graphics card. When I try and start up, I get grey vertical lines across the screen. It then freezes on startup (progress bar on logo screen). I have tried resetting the PRAM (OPT/CMD PR) and replacing the battery on the board. I have also tried starting in safe mode and have gotten logged on but still have vertical lines everywhere and the computer is pretty slow.
Has anyone encountered this? any solutions?
Has anyone encountered this? any solutions?