Video Problems on my Desktop

I was having video display problems on my monitor – intermittant lines throughout the picture, and finally no video at all. I cleaned out the tower and removed the video card. I found dust across a few of the 184 pins on the card and cleaned and reinstalled. Everything work for about an hour, and again the video failed. I am very suspect of the video card and think a new card will most likely fix the problem. Any suggestions? Thanks for the help.