try usin the monitor on another computer. if it works then the monitor is fine and it's probably ur video card dat is malfunctioning. then try take out ur gfx card and insert it into another computer, if the gfx card doesnt work, replace it with a new one.
more info is needed on ur computer...
i've even changed motherboards and have the same problem. im trying to reinstall window xp but with no signal to the monitor im stuck. plz help.

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