I have my Samsung TV connected to my Macbook Air via HDMI/thunderbolt. Everything was working just fine until I upgraded to Yosemite (10.10.5).
At the moment, in the "sound" configuration in the "output" tab I don't see anything except internal speakers and I can see the images on the TV but there is no audio.
[I already rebooted, but with no change in behavior.]
Any idea on how to fix this?