[Precision M4800, Realtek ALC3226, Green Headphone Out, Front] No sound at all

Try alsamixer, press F6 select HDA Intel PCH, then disable Auto-Mute. I attached my configuration on my M4800

I have this same issue with Dell M6800. It works sometimes and after reboot, it stop working.

Status changed to 'Confirmed' because the bug affects multiple users.

Same problem there, also Dell M4800, I am using latest ubuntu 18.10 and it was working until I installed latest nvidia-driver-418. I do not why. There is suspicious message in dmesg.
(If I uninstall the nvidia driver it is still not working and reinstalling of alsa-driver also did not help.)

[ 5.603947] resource sanity check: requesting [mem 0x000c0000-0x000fffff], which spans more than PCI Bus 0000:00 [mem 0x000dc000-0x000dffff window]
[ 5.604084] caller os_map_kernel_space.part.9+0x84/0x90 [nvidia] mapping multiple BARs
[ 6.338946] resource sanity check: requesting [mem 0x000c0000-0x000fffff], which spans more than PCI Bus 0000:00 [mem 0x000dc000-0x000dffff window]
[ 6.339056] caller os_map_kernel_space.part.9+0x84/0x90 [nvidia] mapping multiple BARs

It seems to me that everything is working just some GPIO actually does not enable the output. The system detects the headphones correctly.

I just found the ultimate debug tool for Intel HDA, https://git.alsa-project.org/?p=alsa.git;a=tree;f=hda-analyzer;hb=HEAD and alsa-tools-gui maybe it will help someone

I found the fix. It seems funny but it is really fault of nvidia-driver-xxx. It somehow modifies power settings of the system. I am using latest Ubuntu 19.04 with 5.0.0-11-generic kernel but exactly same problem did happen wit any previous Ubuntu version and also with recent versions of Fedora.

I added the following line to /etc/modprobe.d/alsa-base.conf

options snd-hda-intel enable_msi=1 enable=0,1 model=dell-headset-multi power_save=0 power_save_controller=N

# note that pulseaudio -k && sudo alsa force-reload was not sufficient I had to reboot system because the modules were in some wrong state and they did not unload successfully

1. the enable_msi=1 : interupt setting is there because there is no sound after suspend
2. enable=0,1 : I did disabled the intel hdmi, spdif (non PCM) sound cards because some programs just used the diferent card no matter what was selected in ubuntu desktop controls/alsa mixer and this was the most simple method to get it working (you can list your cards by aplay -l)
3. model=dell-headset-multi this is required otherwise you will hear only cracking if you play something
4. power_save=0 without this you will hear nothing or cracking

Note:
You may also need to run sudo apt-get install --reinstall dkms alsa-base pulseaudio to get the system in to initial state if you modified something recently.

Note:
Out of the box ubuntu installation worked just fine, but after reinstall of nvidia-driver-XXX (415->418) / kernel (if the nvidia driver is installed) the sound just stops working and there is no error msg anywhere (dmesg, syslog) and the output is seems to selected properly and the mute etc is set properly in alsamixer.
The problem is that the nvidia drivers somehow modifies the power settings and this breaks the audio.

I have the same problem on Ubuntu 19.10.
The fix of nic30 doesn't work for me.

I have a Dell Precision M2800

Seems that it still breaks:
https://www.reddit.com/r/linuxhardware/comments/f37ypz/audio_stopped_working_after_upgrade_from_50037/

And nic30 solution either works for me, previously after upgrading kernel I had problems with sound but downgrade was bringing sound back. For now, it's not working on my company M4800, but I need audio because I talk with clients.

I have Nvidia 440.
Thanks!

I have the same problem on Ubuntu 20.10.
nic30 solution works for me.

I have a Dell Precision M4800.

I have a similar problem since today :

no sound when using headphone.

Dell Precision M4800
Ubuntu 20.04.1 LTS
http://alsa-project.org/db/?f=26e936d448899b41700b76e49223ee15e1264d50

I don't have any Nvidia component, all the solutions provided are not working :/

If anyone can help :)

Thanks