Andy, there should be four diagnostic LEDs (labeled 1-2-3-4) on the system that can help determine what the problem is. You can also use the status of the power light (if its on/off/blinking and what color it is) to help with this. If you can post that information (which diag lights are on and the status of the power button light) I can give you an idea of where the problem might be.

Since you just put another card in the system, a good first place to check is to make sure none of the cable came loose while you were working on it. While it seems simple enough, that kind of thing had me going for 30 minutes on a desktop I added memory too once.


Larry
Dell Customer Advocate