LCD Monitor Flickers when trying to play a video?

Hi, I have a LCD Monitor that flickers and the looses the signal when I try yo play a video. Any Help? I have a NVIDIA GeForce FX 5500.

This problem started a few days ago and I don't know how to fix it. I tried updating my video card drivers, updating my monitor drivers...|||install direct X that supports ur new vga card. must be in the driver cd. try to run game at maximum resulation becouse some LCD screen goes to sleep or stand by if it doesnt get the minimum resulation so change the games resulation to maximum..|||install the mother drivers ... i guess its called onboard display drivers ... that shoul solve it