I ordered a new logic board and installed it this afternoon. I was in the middle of installing snow leopard when the computer shut down. Long story short, I found the fan was dead. I replaced with one from another computer. I now can't get 2 seconds past the apple logo. What could be the problem? I've tried starting with the battery out and with it in. Trying different ram from other computers I know are good. I booted in safe mode. I got all the way to the login screen. The keyboard wouldn't type, and then the computer shut down. I had to hold the shift key down all the way to the login screen. Battery seems good. Held full charge over a week. I tried the hardware test by hold the D button down. I am not sure if it worked or not. I never saw a report.