I’ve been struggling for a while with lack of sound in headphones on Asus G751JT running Ubuntu. The solution was so silly, that I decided to write about it.
After numerous attempts to change Alsa and Pulseaudio configuration, I finally googled this thread. As you can read there, moving the headphones jack to the last audio port solves the issue. This was really weird, as the third port is an audio input (you can find all audio ports clearly described in the manual). I decided to give it a try, and unexpectedly, it worked!
Leaving it here as a note for myself, maybe you’ll find it helpful too ;)