Flatscreen monitor blinking - no screen

[Dennis]

Suddenly, my flatscreen monitor does not seem to get any
signals from the PC.

The power indicator just blinks as if a black screensaver
or something was active. The cable and monitor is though
alright, Ive successfully tried using it with another PC.

BUT with my stand alone pc it does not work. And when I
detach the monitor cable, a message appears
stating "check monitor cable". But that is fine.

- Could there be any setting in Win XP that has caused
this problem?

I do frequently switch monitor cable between a beamer and
the flatscreen monitor...

Thanks,
Dennis