My old mac pro doesn't work and I think it's the graphic card that is the problem. The computer seems to start as normal. All the right sounds are there but there is no image on the screen. I can get a second hand NVIDIA GeForce GT 120 with 512MB of GDDR3 ram Graphic card for a good price but I need a confirmation that it should work, if the graphic card is indeed the problem. You advice will be appreciated.