Can you get into the BIOS? If not the bad hard drive may interfer with the boot process. Try removing the HD and booting without it in the computer. You can download and run Digtal Dolly
(Hard drive utility). The S.M.A.R.T. utility will inform you of problems with the hard drive.
Create a folder to download DD into. Unzip the files into that folder. Burm and image to cd. This will boot to a Red Hat GUI. If these option do not allow you to boot the hard drive is not the problem.