[PLUG] I'm trying to get sound through my headphones.

[Genaro Hernandez]

Hi everyone.

I recently installed Ubuntu 12.04 on an old MacBook. Everything seems fine
except I can't get sound through my headphones. I can only hear audio
through my built-in speakers. Whenever I plug in my headphones, there is no
sound and there is a red light that glows from the jack.

I've searched for a solution online but so far nothing has worked. This
link describes the exact problem but their solution for modifying the file
/etc/modprobe.d/alsa-base.conf did not work for me:
http://www.upubuntu.com/2012/04/headphones-not-working-no-sound-under.html.
This other link also describes a solution by modifying the alsamixer.
However, I do not see a headphone jack listed in the alsamixer.

Does anyone have any suggestion(s) for me? Do you think that upgrading to a
newer version of Ubuntu would fix the problem?