My Yosemite just greyed out my volume slider, volume keyboard keys don't work either.
When I go to system preferences and click on sounds, it just froze system preferences. I tried earphones and other things, no avail.
If I fire up Skype and go to Audio and Video settings, it does not output sound does not record sound and even says no camera.
Anyone has this problem? Because I couldn't find any one reporting this on the internet.
