Laptop headphone jack produces no sound

Question

The headphones are detected, because when they are plugged in, they appear in the sound settings.

The problem is that they just don't output any sound.

Laptop speakers output sound just fine.

I'm running Ubuntu 16.04 x64

This is the output from running alsa-info.sh:

http://pastebin.com/1aDcq86B

What steps can I take to try and debug this issue myself?

Edit 1

Thanks to @Rexford and this answer, I've worked out how to get detailed debugging output from pulseaudio, by temporarily modifying /etc/pulse/client.conf using the --log-level flag.

I'll report back after I play around with this new information and try to find the problem.

Edit 2

Woke up this morning planning on getting to the bottom of this issue, when I discovered that the sound from the headphones started working.

Last night I had tried many solutions (from various forums and webpages), but was not restarting my computer (was just doing pulseaudio -k && sudo alsa force-reload).

So I guess that the reboot was necessary to make one of the solutions kick in and actually work.

One of the biggest things I tried was uninstalling pulseaudio, installing gnome-audio as a replacement and going back to pulseaudio. So I recommend others try that if they are struggling. Just note that if you do that, you should follow the instructions here to get your volume/sound icon back (if it's missing after reboot - which it was for me).

I can't get to the root of this problem now, because it no longer exists for me.

Edit 3

The problem came back...

Debug logs from pulseaudio don't reveal anything useful (e.g. error messages).

According to this diagram, alsa is the next stop to check for the cause.

Solution

This answer appears to be working for me, but I have not investigated why yet.

To repeat the solution, just run this command in a shell (no root needed):

alsactl restore

Comments

[Admin]

First, is your headphone working? Try with another device to confirm! Second, is your laptop jack working? Try another headphone to confirm! If headphone and laptop jack is working, then back to software. Thinking of what could go wrong, but check the above and let's see.

[Admin]

Headphones work fine in my phone and have also tried another working pair of headphones in the laptop.

[Admin]

Okay, thanks. Please, have you seen this? askubuntu.com/questions/219342/…

[Admin]

I had not. This is what I was looking for (ability to get more detailed debugging information about what is going on with regards to sound), Thank you very much, I'll update my answer.

[Admin]

I have the same issue with 17.10.

[Old account]

This works for me too and I don't understand why! Scary!

[edelans]

Worked for me as well. I lost the sound on my headphone after I upgraded my linux kernel from 4.4 to 4.12, on my dell xps 13 (9360) running on ubuntu 16.04.

[Dr_Zaszuś]

Didn't work in my case...

[pleasedesktop]

@Szczypawka yeah sometimes it does for me and sometimes it doesn't. Sometimes rebooting after running that command helps.

[a coder]

Did not work for me.

[R.S.]

This worked on Ubuntu 16.04 after a botched up session with QjackCtl created all sorts of troubles with the headphone.

[user3375672]

This worked for me (restoring sound driver configuration)

[Dong Nguyen]

work for me, Ubuntu 19.10 Gnome classic 3.34

[Josh]

Still needed/works on Ubuntu 20.04 LTS

[Brayam Valero]

This answer also worked for me. My situation was I was logged in with one user, then logged out and logged in with another user. Headphones were mute, but speakers and HDMI sound output was fine. alsactl restore worked.

[n1k31t4]

From man alsactl, it says: alsactl - advanced controls for ALSA soundcard driver. Then for this specific command: restore loads driver state for the selected soundcard from the configuration file. If restoring fails (eventually partly), the init action is called.

[Nocturnal]

Works for me on Ubuntu 20.04 ! Thanks a lot!!

[Nocturnal]

Works for me on Ubuntu 20.04, but the sound plays both on head phone and laptop speaker.