Startup Problems - no picture
Computer sounds like it is starting, the cdrom light may be on; the fans will be spinning, the hard drive is spinning, but the usual startup text/images are missing. The computer does not go beep when it usually does.
In most cases, there is nothing wrong with your screen.
One (or more) components on the motherboard have failed.
Common points of failure
* The electrolytic capacitors near the CPU - make sure the tops of these are all flat. It may be time to replace them if they are slightly rounded.
* Make sure all fans are spinning, especially the ones near the cpu and power supply
* The reset switch is being held down. Unplug the wire to the reset switch at the motherboard and try again
* Power supply may have failed. Try another one.
* Dust. Time for a spring clean.
* BIOS chip may be loose, or have been wiped.
* CPU may have overheated. Clear out the dust between the heatsink and the CPU fan.