I installed a vanilla version of Ubuntu 14.04 (Desktop, 64-bit) on my Lenovo Thinkpad W540. The sound works well on the built-in speakers, but I get no sound from the headphone jack. In the sound settings, I can see my headphones as an available option, and I know it's not muted. When I toggle the mute box, I can hear a little "dit" coming through the headphones as the audio feed is being disabled/enabled. But no sounds that are sent to the headphone output is actually coming out.
I will say that when I plug in the headphones, the internal speakers mute. But I cannot figure out why I'm getting no sound.
Attached is a screen-shot of my alsa-mixer: alsamixer screen-shot
I do find it a bit odd that there are two entries for the headphones. Are there any suggestions or anyone else with a similar problem?