Why does my TV keep going blank but the sound still plays?

@nataliejf this sounds like you are losing the backlight on your TV. When it goes dark use a flashlight and shine it at an angle against your screen (in a darkened room of course). If you can still make out silhouettes etc. then it is your backlight. Could be the power board as well as the backlight array itself. If you cannot then it is possible that this is caused by a bad t-con board etc. Post some images of all of your boards with your question, use this guide for that Adding images to an existing question. This will allow us to see what you see,