Today when you turn on my TV, it is only heard and the screen looks black. It does not give the image. And when you put it in a dark place you can hardly see the brand of the TV

You have problems in the backlight circuit, it may be that some LED was damaged, but to repair that fault if it is by LED, you need a professional because you could split the screen since it is not easy to repair it. If you want you can follow me on my channel that I will soon be publishing a repair video of this type of failure. Here I leave some of my videos to get you easier on YouTube. regards