saint19 you give this recommendation to each one that complains, or has problem with his LCD. It isn't quite right, because you will be amazed, that there are people that can report on a faulty monitor, when the problem is a loose connection.
Yeah, I guess check the cables, try two different computers, use different cables and power outlets if you can.
If that doesn't work, are you still in warranty for the monitor? If so, then try to get a replacement.
Do you want a new screen anyways? This is a great excuse to upgrade. =D
I remember trying the VGA on the IO plate, but that didn't work on a computer a few years back... returned it to find out the integrated video was disabled and needed to use the discreet VGA port (my first comp with a discreet)...
Later my monitor went to hell. Just jiggling the power cord usually did it (with several different cords).