TV still has negative picture

@rosew your question got converted from a comment you had left on this question picture on screen looks like a negative picture

First, we would need to know what model your Samsung TV is. Second, we would need to know what your screen is displaying. Post some pictures of that with your QUESTION (you will have to edit your question to attach pictures) Aggiungere immagini ad una domanda

Since you are our eyes and ears you will have to set the color and screen inversion in the menu and make sure that you those are set properly. After that remove the back from your TV and check all the cable connections. Make sure that the cables are properly seated and that there is no corrosion etc. Post some pictures of your boards with your QUESTION as well. This does sound very much like a T-con board issue. Replacing the T-con should correct the inversion. Again we need to see this to verify.