My trusty old NVidia GeForce FX 5200 has been malfunctioning recently, usually when i play videos or games. Whenever i start a video or a game, the monitor will start going on and off with about 3-second intervals. It keeps doing this for a while, and then the computer freezes.
I have tried updating the drivers and reinstalling, but nothing has worked so far. I'm really not sure what's wrong. Anyone got a clue?
You could try swapping in another gfx card to see if that's really the issue, but it sounds like it could be heat-related, since it's a problem when the card is being taxed. What kind of temperatures are you running?
Alternately, the card could be simply dying. It's not the youngest thing out there.