回答“No audio, and no "Internal Speakers" in SystemPrefs>Sound>Output”Hi, I had the same problem - No audio, and no internal Speakers in System prefs > Sound > Output. The solution what helped me was easy: "Press and hold the power button until it shuts down. You'll lose unsaved work in any open applications. Then press the power button again to turn on your Mac." I tried simply restart before this, but restart wasn’t enough.