Mac Mystery Mute (Basic Sound Troubleshoot)

On occasion, a MacBook is persistently muted.  Often times this is a symptom of the audio output being rerouted to a speakerless second monitor (HDMI output).  Below is a visual guide to fixing this and troubleshooting basic audio output mix-ups.

1. The Issue

2. Open System Preferences 

3. Identify the selected output

4. Switch to desired output (usually Internal Speakers)

5. Resolution