You can try factory resets (in the manual) and if that fails get a repair estimate to see if it's cheaper to repair or replace.
I have a Samsung LN46A630M1F. Last night while watching tv. The picture got darker and the faces got red. I watched the program on my iPad and everything was fine. So I knew it wasn't the dish signal. I tried adjusting the settings. The only thing that helped a little. Is turning the brightness to 100%. Yet they still have red faces. Any suggestions??