I have exactly the same problem : https://askubuntu.com/questions/580640/no-headphones-audio-in-alienware-15-laptop/643569#643569
I also have an Alienware 15. Everything works great with Ubuntu 15.04 ... Except wifi and headphone ... There is no sound and I can't even find any "headphone" in alsamixer when it is plugged.
I have tried to reinstall alsa and pulseaudio. Did not change anything. I have modified analog-output-headphones.conf and alsa-base.conf like in this post : Headphone jack not working?
Same problem ...
lspci returns me :
00:03.0 Audio device [0403]: Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor HD Audio Controller [8086:0c0c] (rev 06)
00:1b.0 Audio device [0403]: Intel Corporation 8 Series/C220 Series Chipset High Definition Audio Controller [8086:8c20] (rev 05)
Probably the HDMI port.
If someone has found a solution.
Thanks!
