Hello. I just got a Dimension 8100 computer from my brother, and after taking it apart to clean it, I plugged everything back in, and turned the power on. The computer seemed to start okay, and it appeared that it booted the cd drive, but nothing happened after that. There was no action from the hard drive, and nothing came up on the monitor. I tried to put in a newer graphics card, thinking that it was the issue, but the same thing happened with the newer card. Opening up the computer, i noticed a steady amber light coming from the motherboard that I do not believe was there before when the computer was working. I looked at other troubleshooting sites and checked the diagnostic lights in the back of the machine, they showed all green. I had also read that a steady amber light on the computer power switch indicated a power supply problem, but my light is still green. What could possibly be my problem? Any help is greatly appreciated.