I have a Sony Vaio laptop that used to play sound through my LG TV but now it will not. It only shows picture and plays sound through the laptop still. When I go to playback devices it shows the TV on there but it says that is working properly but not plugged in. The option to set the TV to the default playback device is grayed out along with the test option. The other device on playback is just the laptop speakers, Realtek. I've tried disabling and re-enabling, restarting, and using different HDMI cables, nothing works. I need some help figuring this out.