That is what happens when the electronics blows up. Time for a repair. I do my own electronics repairs. Most times the components aren't that expensive, but electronics repair shops are rare these days and expensive enough for their labour to think about investing that money in a new model instead.

Paul! Try opening set-up from there you go to picture. There you put as much brightness as you can. Maybe you should try to change channels before, there is a small chance that the tv responds to that. All the best Kolbrun