I'm sorry to hear that you're having an issue with your TV.
Unfortunately, it's difficult to determine what the problem would be without first inspecting the unit. I'd recommend calling 800-SAMSUNG and having an inspection for your unit set up to determine what the problem might be.
I purchased the tv about 2 years ago and it has been fine. Now the color has gone crazy. No lines, just overblown color which at first would go away after about 10 minutes. Now it stay that way all the time. Help??!!