Why do I get sound but no picture?

@randallnod22 first we need to know what make and model your TV is. You posted the same question to two different makes. No video but audio could be a bad T-con board and also a bad backlight. In a darkened room and with the TV on and sound audible, shine a flashlight beam at an angle against the screen. If you can make out shapes/silhouettes, you know it is your backlight that has failed. To repair that you will have to disassemble your LCD panel. Not terribly complicated.

If you do not see anything, I would focus on the T-con board and check the wiring to it etc. most likely replace it. For any clarification etc. Post some good pictures of your TV's boards and interconnect wiring with your QUESTION. That way we can see what you see. so we can see what you see.

Adding images to an existing question