Macintosh internal speaker output volume fix

This is a frequent problem on mac when the internal speakers go mute. This are the solutions I found on the internet which also worked for me many times on different systems on mac platforms.

Scenario 1: 

Its a problem when a switchers gets jammed. It seems to work with headphones but the internal speakers does not give any sound output.  (I am no mac expert so you can search about it on the internet)

1) Open system preferences and go to sound control preference and then select the output tab so that you can see your output options.

Get your headphone audio jack and then gently poke around the back your audio output. 

The aim is to poke a  switch inside jack output which needs to get pressed.

Scenario 2:

Watch the output in the system preferences as it turns from Built-In Speakers grey.

1) In a finder window select/open: Macintosh HD - Library - Preferences - Audio


2) Copy any files in this audio folder onto your desktop to keep as a backup.


3) Delete any files in the audio folder


4) Open the System Preferences - sound control preference and then click a few things to force the computer to generate new uncorrupted plist (or preferences list) files in the folder you just purged.


5) If all goes well and you have sound through a built-in-speaker audio output option delete the "backup" .plist files you copied to the desktop.

Credits: https://discussions.apple.com/thread/2767922?start=0&tstart=0