Computer trouble..please help me!?

for a while now, my computer has been totally effed up. the screen is a bluish-green tint to it, and will not show any red. This can make playing games and looking at pictures miserable. At first i thought i just needed a new video cable, andit worked, for a little while. now ive tried ANOTHER new cable and its not working. please help, im desperate. ps its not the monitor..