|If this is a laptop or netbook, try an external monitor - see response 1:|
If this is a desktop computer, try a different monitor with your computer, or try your monitor with a different computer.
A friend of mine has an older LG LCD moniitor that developed failing electrolytic capacitors on a board insde the monitor.
I replaced two capacitors with high quailty ones and it's worked fine ever since.
Symptoms for at least several months -
It always had video when you first booted the computer on a particular day.
The screen display would go black while the computer was running for no reason at all, usually after the video had been fine for a long time.
If you rebooted the computer (you need to know the proper keys to press - for 2000 or XP that's Alt-Ctrl-Del, then Alt-U, then U for Turn off, or R for Restart ) , or pressed the power button in for at least 4 seconds until it shut down, then booted the computer, the video was fine for a while again
- then - it had video when you first booted, but when the video went black after a while, no video no matter what you did. If you let the computer sit turned off for a while, the same thing again when you booted it again. .
- then - no video no matter what you did