TV LCD Toshiba 46wx800

@antoniolg going by your description alone, it sounds like a bad LCD. The only way to fix that is by replacing the complete panel. Here comes the bad news, panels that size are rarely available and will most likely cost more than a new tv (if available). You can pof course try a search based on the label that is affixed to the panel itself and see what you come up with. Another possibility would be to try to find the same make and model TV as yours ut that is broken differently. Then harvest the panel from that. Of course this is based on your description. To verify this, post some images of what your screen displays with your question so we can see what you see. Use this guide Aggiungere immagini ad una domanda for that