No picture but I have sound

@sheffwife we need your TV's complete model number. You also should let us know what you have already checked (Tried all different Video input sources etc.) You also want to try to unplug the TV and unplug all accessories connected to it. Then hold the power button depressed for something like a minute or two. After that plug one video source, preferably local like game console, DVD/BR player etc. and see if you now get video. If not the check in a darkened room, shine a flashlight at an angle against the TV screen (TV must be on and you have to have sounds etc.). If you can make out shapes, silhouettes etc., then you know that this is a backlight issues. If not then there is the possibility that this is a main board, power board, T-con board or even the display panel. We would need to see your boards etc. to make any kind of further repair suggestion.

Adding images to an existing question