No picture only sound

Doreen Timmers  possibly. In a darkened room turn the TV on and make sure that you are on a channel that is broadcasting( verify that you have sound etc.), then shine a flashlight at an angle against the screen. See if you can make out shapes or silhouettes etc. on the screen. If so it is your backlight that is not coming on. That could be a backlight array issues, main board issue or power board issue. If it doesn't show anything, remove the back from your TV and check the boards. Post some good images of those boards with your question. that way we can see what you see and possibly identify bad components etc. Adding images to an existing question

Of course, you also want to tell us what model your TV is.