Comment 9 for bug 1551880

As far as I can tell I'm seeing the same sort of problem with a clean install of Ubuntu Mate 16.04 on my Dell XPS 13 9343.

From what I can tell, the machine thinks it's playing audio. If you look at the input tab of the sound preferences when a youtube video is playing, it's clearly processing something. But no sound ever comes out of the speakers. Also, if I plug speakers into the headphone jack, it results in a high pitched whine which is constant and persists even if I mute everything.

Happy to provide any additional info if I can.

Attaching the output of alsa-info.sh.