System details: http://www.alsa-project.org/db/?f=ca96b1ad9d7f3d393a59566f0ca6b8ea765be023
I've tried everything I could find, asked on the IRC channel for help. I didn't get too far. After 5 hours of trying, I managed to get some low volume, distorted sound from my headphones. (My built-in speakers still work fine).
Any related details are included in the link pasted above.
The "sound" started coming form the headphones after I set every possible value in the alsamixer to the highest number and added the following code to the alsa-base.conf file :
options snd-pcsp index=-2
alias snd-card-0 snd-hda-intel
alias sound-slot-0 snd-hda-intel
options snd-hda-intel model=laptop
options snd-hda-intel position_fix=1 enable=yes
Best Answer
FIXED IT: for anyone else having the same problem, I got it to work. Edit the snippet of code I've posted in my original post into your alsa-base.conf file. (type gksudo gedit /etc/modprobe.d/alsa-base.conf into a terminal)
Fully shut-down your computer and start it up again. Rebooting won't do it. Your headphones should now work.