My Graphics card is an AMD Radeon HD 7870.
This problem started a few months ago. I went to my playback devices and my TV wasn't in the list even though it was connected and displaying perfectly fine. For some reason whenever the AMD drivers all update to the latest version, my TV disappears from playback devices(so no audio comes out of the TV but display is ok). This seems like a problem with the AMD HDMI Audio driver but the problem is AMD aren't fixing the problem with newer updates. It's been like it for months now!
My only work around this problem is to use the AMD removal tool to remove all my drivers, then reinstall an old version 17.3.3 from March! So I'm stuck using an old version and now every day my computer decides to update to the latest drivers even though I unticked the box. So I have to reinstall the drivers every day. I have seen other people online also with the same issue but AMD aren't fixing it.