Old laptop wont go past the bios screen

My laptop is a Dell Latitude L400 10″ traveling laptop, so no floppy or cd drive and has 1 usb port and has XP Pro installed. When I turn on comp. it does not go past bios screen. What could be the problem. I installed another floppy from my other laptop that is same model, but it does the same thing, so know it is not the hard drive. I try to go into the bios but it will not do that either. I was thinking maybe the bios was corrupted but that is just a guess. Any suggestions?