I have a Mac Pro 1,1 (bought in 2007) with original NVIDIA stock card. Last weekend I noticed that my screen suddenly started to display squiggly green horizontal lines and then my computer was unresponsive. Shutting it down and starting it back a few minutes later resolved the issue but it kept coming back. I checked for overheating and dust overload - cleaned it out with canned air and that helped for 3 days then yesterday the problem continued and persisted. Now I cannot do anything. It boots up - Apple logo displays but not much else happens. Checked for issues with TechTool Pro and original apple hardware diagnostic tool and it proved useless. Even reseated video card to another PCI port - no resolution. Zapped PRAM, reset SMC, removed hard drives and ram and no resolution. I definitely feel it is the graphics card that is fried. Do you all agree? So... though I know this system is old, it suffices for me at the moment. I cannot drop 3k on a new Mac Pro! Please advise - where can I get a video card for this machine? Is it worth it? Can I use a PC card and flash it (no idea how to do that but willing to learn). I'd love to get another year or two out of this system!