If you're using your computer and the monitor screen suddenly stops working, it's key to figure out if it's the computer or monitor that's having the problem. Diagnosing what is wrong and fixing it is ...

I purchased a 19" Viewsonic A90 from a friend of mine, and it seemed to work okay (the light goes on, etc.), but no picture appeared on the screen. I examined the VGA cable more carefully, only to ...