I recently upgraded my OS to Yosemite 10.10.4
After done my volume icon is greyed out and no sound is found. This is not the bug where it is set on HDMI since when i open output there is no internal speakers nor does it find a pair of head phones.
It will still detect bluetooth and HDMI sound.
Any takers on a good answer?
Best Answer
While I've never experienced this issue in Yosemite, I did have issues with audio output on an older OS. If I remember correctly, my solution was to reset the core audio.
The following is reason to believe some have experienced loss of audio in 10.9: http://www.imore.com/losing-audio-os-x-mavericks-heres-what-you-can-do-about-it
This thread shows a means of automating the process, in case that solves your problem: http://forums.macrumors.com/threads/create-a-service-to-reboot-core-audio.1697918/