Okay so this is just to clarify a few thins. always check your TV’s settings first. Make sure that it is not on some grayscale settings etc. After that check every input source to see if that makes a difference. Try HDMI, Component, COAX, and whatever input source your TV may have (also try different cables). If that checks out okay you will have to look behind the back cover. The most common cause for black and white is actually a failed Gamma IC on the T-con board.