(K)Ubuntu 17.10 - No Audio devices found, no settings, no sound

I had the same problem and seeing the logs in /var/log/syslog I had an error for pulseaudio daemon:

[pulseaudio] module.c: Module "module-switch-on-connect" should be loaded once at most. Refusing to load.

So I opened /etc/pulse/default.pa and edited it using # to disable 3 lines:

#.ifexists module-switch-on-connect.so
#load-module module-switch-on-connect
#.endif

Maybe it'ś not the best solution but it solved my trouble.

I have solved this by reinstalling pulseaudio.

Pay attention: if you have some custom edits inside /etc/pulse, they get lost if executing rm -rf /etc/pulse as shown below! In my case there are only a hand full of files that have been reinstalled.

Update 2019: take care if package plasma-desktop is uninstalled while removing pulseaudio. Reinstall before booting, otherwise your system may not boot properly.

• apt-get remove --purge pulseaudio
• rm -rf /etc/pulse (maybe remove $HOME/.config/pulse also)
• apt-get install pulseaudio
• apt-get install plasma-desktop
• reboot

This also deinstalled some other packages (like oss*) which have not been reinstalled, and in my case, I don't miss them at all. ;)

[EDIT]

If your card is listed by something like sudo aplay -l, but not listed in pavucontrol, your card may be blocked by further processes. Check that sudo fuser -v /dev/snd/* doesn't list any other processes than pulseaudio. In my case when upgrading to kubuntu 19.04 it was blocked by squeezelite process, so I stopped and disabled squeezelite and everything was fine:

$ sudo fuser -v /dev/snd/*
/dev/snd/controlC0: root  872 F..... squeezelite
/dev/snd/pcmC0D0p:  root  872 F....m squeezelite
[... bad ...]
$ sudo systemctl disable squeezelite
$ sudo systemctl stop squeezelite
$ pulseaudio -k
$ sudo fuser -v /dev/snd/*
/dev/snd/controlC0: myUsername 1459 F..... pulseaudio
[... good ...]
$ pavucontrol

... et voila! My soundcard is available inside pavucontrol again.

I had the exact same problem (same symptoms) and ended up wasting hours looking for a solution. I solved the issue by editing default.pa to statically load modules and replaced hw:1,0 with hw:0,0

sudo nano /etc/pulse/default.pa

Content to change:

load-module module-alsa-sink device=hw:0,0  
load-module module-alsa-source device=hw:0,0  
load-module module-null-sink  
load-module module-pipe-sink  

Save and exit, then run:

sudo alsa force-reload  
pulseaudio -k  
start-pulseaudio-x11  

Hopefully you have sound at this point.

just refuse back or reload pulseaudio service/etc that directly behave on..

first check up if ther's no any hardware issue that's mean hardware it self are on nice condition and detected with driver and them self is installed/good

use lspci aplay -l or whatever that can help you to determine the device is okay

next just refuse it back, you can use any daemon service reloader that can help you to refuse your service it self

or just force with fuser -fkv /dev/snd/* -v for verbose -f for force -k for kill -last - following by the service is sourced

I ran into same problem. After installing pavucontrol I restarted my system and now it's detecting my sound card and headphones.

sudo apt-get install pavucontrol

In case pavucontrol giving errors after installation, restart your system and they will be gone.

Hope this helps others too.

try to find in .config/ if there another folder that config the pulse in my case it was google-chrome-remote-desktop app, that was create another profile with pulse-audio config that prevent the normal profile to load

I'm having the same problem in Kubuntu 17.10. I cannot say what the cause was, it happened after I plugged in the HDMI cable or after I paired a Bluetooth speaker and changed the output audio stream to it. After some searches I mixed up some solutions. Audio seems to work now but I'm wondering if this is a good or bad solution. What I did was:

sudo apt-get remove --purge pulseaudio
sudo rm -rf /etc/pulse
sudo apt-get install pulseaudio
sudo reboot

Audio was up but there was no way to control it. Icon in the system tray disappeared. So I did:

sudo apt-get install plasma-pa
sudo reboot

At the reboot the icon was in the system tray but audio was mute and not working, exactly like here. So I removed plasma-pa and installed kmix. Doing this, audio is working now.

sudo apt-get remove plasma-pa
sudo apt-get install kmix

I'm not sure this is a good solution and I'd like to know what the problem is with plasma-pa, but at least the problem is gone.

@peterling 's answer worked for me it is the last one on this page: askubuntu.com/questions/70560/why-am-i-getting-this-connection-to-pulseaudio-failed-error

He said I had to enter this in the terminal:

sudo pulseaudio -k
pulseaudio --start

this is what it looked like on the terminal:

lubuntu@lubuntu:~$ sudo pulseaudio -k
E: [pulseaudio] core-util.c: Home directory not accessible: Permission denied
E: [pulseaudio] main.c: Failed to kill daemon: No such file or directory
lubuntu@lubuntu:~$ pulseaudio --start
N: [pulseaudio] main.c: User-configured server at {2d68ac8ceac9497599efde6fcfca4f8c}unix:/run/user/999/pulse/native, which appears to be local. Probing deeper

After this I ran pulseaudio volume control From using the normal shortcut by clicking on it in lUbuntu 16.10 You're using a much newer version of KUbuntu but I think this might work for you because we have this in common: "

I tried start-pulseaudio-x11. Output:

Connection failure: Connection refused
pa_context_connect() failed: Connection refused

"

Don't have enough rep to comment, but I tried the 3rd solution above by ChristophS. While this looks like a good solution, on Kubuntu 18.10 using purge uninstalled my plasma-desktop and kubuntu-desktop. I had a bunch of unnecessary packages listed from a wine uninstall, I plan to reinstall. Needless to say caused quite the confusion, especially paired with the permission changes which ended up being the cause, which I thought messed with the desktop.

Lesson being: be careful what you purge! I think there should be a comment on the above solution to warn about the current inclusion of desktop with purge pulseaudio.

apt -s remove --purge pulseaudio
Purg kubuntu-desktop [1.379]
Purg plasma-pa [4:5.13.5-0ubuntu2]
Purg plasma-desktop [4:5.13.5-1ubuntu4]
Purg libcanberra-pulse [0.30-6ubuntu1]
Purg pavucontrol-qt [0.4.0-1]
Purg pulseaudio-module-bluetooth [1:12.2-0ubuntu4]
Purg pulseaudio [1:12.2-0ubuntu4]

If hack from the above link works, might be the permissions: HOME=/tmp/$USER pulseaudio --start

I had a similar issue due to pulseaudio-equalizer:

sudo cat /var/log/syslog | grep pulseaudio
[pulseaudio] module-equalizer-sink.c: module-equalizer-sink is currently unsupported, and can sometimes cause PulseAudio crashes, increased latency or audible artifacts.
[pulseaudio] module-equalizer-sink.c: If you're facing audio problems, try unloading this module as a potential workaround.
[pulseaudio] module-equalizer-sink.c: Master sink not found
[pulseaudio] module.c: Failed to load module "module-equalizer-sink" (argument: ""): initialization failed.

So I uninstalled it:

sudo apt purge pulseaudio-equalizer

After a reboot I had:

[pulseaudio] ltdl-bind-now.c: Failed to open module module-equalizer-sink.so : module-equalizer-sink.so: cannot open shared object file: No such file or directory
[pulseaudio] module.c: Failed to open module "module-equalizer-sink".

Removing the line load-module module-equalizer-sink from ~/.config/pulse/default.pa didn't fix the issue.

I finally found the solution by flushing my configuration:

~$ cd .config/
~/.config$ mv pulse/ pulse.bak

And reboot (pulseaudio --kill / --startw wouldn't refresh the sound widget).

I just opened a related bug in launchpad: https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/1859996