What is that buzzing noise

Liz Farnam  could be a coil or a transformer. First we need to know your TV’s exact model number. Then you need to disconnect everything else on your TV with the exception of one video input. Restart your TV and see if it still makes that buzzing noise. If it does, remove the back of your TV and turn it on. See if you can identify the general area where the buzzing comes from Post a couple of good pictures of your boards (and point the “noisy” area out) with your question. Use this guide Adding images to an existing question for that. This will allow us to see what you see and hopefully guide you to a good resolution of the TV’s issue.