I don't know where to post this but I'm at a loss. I hope someone can help! I have a Power Mac G4 Quicksilver tower, 2001. My video card was going out so I bought one on ebay. Same exact card, same numbers on it. When I put it in the machine, it won't turn on. If I take it out and leave it out, or put the old card in, the machine will run. Put in the new one, it won't turn on. Anyone know what the problem is? The seller sold it as tested and working. Actually, I've tried another video card, too, and the same thing happens. It, too, was tested and working.... until it went into my machine. I put in a new PRAM battery and reset the PRAM, NVRAM, and PMU. Nothing is fixing this. Any advice would be appreciated. I'd like to have at least one of them for backup, since I have them. Thank you!