I have spent some time searching around the various threads relating to headphone issues in Ubuntu and none of the answers seem to resolve my issue, so I will post it here. This problem started a couple of months back when I was running 15.10, and persists now that I am running 16.04 (upgrade, not clean install).

Whenever I plug headphones into my laptop (Asus X202E-DH31T-SL) there is a strange noise (rising then falling static, followed by a loud pop) and then no sound. Sound comes through the built-in speakers fine, and goes out over HDMI fine. The headphones work with other devices. I have tried several pairs of headphones all to the same effect. Upon plugging the headphones in a dialog now appears stating 'unknown audio device'.

A dump of ALSA info can be found here.

I have tried the following:

  1. Checked alsamixer sound levels - no issues.
  2. Made changes to /usr/share/pulseaudio/alsa-mixer/paths/analog-output-headphones.conf as listed here. No success.
  3. Made changes to /etc/modprobe.d/alsa-base.conf as listed here, and tried multiple values for model as listed under the ALSA model list. No success. Each time I did a sudo alsa force-reload and unplugged/reinserted headphones, to absolutely no avail.
  4. Removed and re-installed both alsamixer and pulseaudio but this was not successful.

A dump from dmesg can be found below :

[    8.261817] snd_hda_codec_realtek hdaudioC0D0: autoconfig for ALC269VB: line_outs=1 (0x14/0x0/0x0/0x0/0x0) type:speaker
[    8.261825] snd_hda_codec_realtek hdaudioC0D0:    speaker_outs=0 (0x0/0x0/0x0/0x0/0x0)
[    8.261829] snd_hda_codec_realtek hdaudioC0D0:    hp_outs=1 (0x1a/0x0/0x0/0x0/0x0)
[    8.261832] snd_hda_codec_realtek hdaudioC0D0:    mono: mono_out=0x0
[    8.261835] snd_hda_codec_realtek hdaudioC0D0:    inputs:
[    8.261839] snd_hda_codec_realtek hdaudioC0D0:      Mic=0x12
[    8.273953] ieee80211 phy0: Selected rate control algorithm 'minstrel_ht'
[    8.274480] ieee80211 phy0: Atheros AR9485 Rev:1 mem=0xffffc90000d00000, irq=17
[    8.290195] input: HDA Intel PCH Headphone Mic as /devices/pci0000:00/0000:00:1b.0/sound/card0/input13
[    8.290321] input: HDA Intel PCH HDMI/DP,pcm=3 as /devices/pci0000:00/0000:00:1b.0/sound/card0/input14

Any help much appreciated. I'm at the end of my efforts here, with the next stop being a wipe and clean install to see if that resolves the issue. I'd prefer not to do that.