|Did you reboot the computer?|
If so, what happened?
Did you get anything on the screen?
Did you hear any beeps, if so, how many and in what sequence.
I hope your turned the computer off before you started messing about inside.
Just to clarify in case you misunderstand what is meant by re-boot as so many do. It just means pressing the power button and starting the computer from scratch. It doesn't mean reinstalling the operating system.