My tv screen went black

jaroslavmallak so you can see the image when you shine a flashlight beam at an angle against it. If so (and its pretty common for this brand) you will need to replace the backlight strips. For that, you will have to disassembly your TV which includes removing all the boards. etc. After that you will have to remove the display assembly from the plastic housing (Bezel). Once you got all that (sounds complicated but its not) remove all the sheet metal from the assembly. That will get you into the panel. Carefully with those “plastic sheets” (Diffusers, Polarizer etc.) Mark them the exact way and direction in which they are inside the panel. Now you should see the backlight strip (this should be an edgelit panel) glues to either the bottom or top edge of the case. Replacing that should get your TV backlight fixed. Part to be very careful of is the LED panel itself since it is very thin, so make sure you do not flex it etc. and the diffuser sheets. always make sure they go back exactly the way they came out.
If you are stuck with any of this you can always post a couple of pictures with your question and I am sure somebody will help you further with it. iFixitでの質問に画像を追加する方法

This is not a terrible bad or complicated task, just take your time and have plenty of room.