picture goes black but the sound stays on

@kirstynma3boys that depends on the make and exact model of your TV. It is possible that this is a T-con board error (less likely) or a backlight error(most likely). Once the TV turned black, (in a darkened room) shine a flashlight at an angle against the screen. See if you can make out shapes/silhouettes. If so you know it is your backlight. If not you will have to remove the back cover from your TV and check a few things (power board/ main board) out. Once you give us more details we can try and get you hooked up again.