Speakers on macbook won't work

[XFacta82]

When I plug in computer speakers the sound works, but when nothing is plugged into the headphone jack, when I press volume up or down it won't let me do anything. Also there is a red light showing out from the headphone jack. How can I fix this?

 

[KoolStar]

That means that the digital audio out is enabled. Sometimes if you plug in and unplug your headphones multiple times it will disable the digital audio. Also you can go into System Preferences and change the default audio device back to the speakers.

 

[Neil321]

Here's a whole thread on the subject searching is a good thing