I have Kubuntu installed on an HP Omen and everything was fine until 2 events happened that I attribute may be due to the sound being completely gone.
The first was that a new update of the Nvidia 440 driver arrived from repository ppa: graphics-drivers / ppa
And the other event was that I wanted to install GLava in Kubuntu from a PPA but it could not be installed due to the lack of a library.
After that, I left the computer on, and when I came back there was no sound at all.
There is no sound from the speakers and also when connecting headphones
I Uninstalled and reinstalled pulseaudio and nothing
I think it is a problem with HDA Nvidia with PavuControl all the profiles appear unplugged.
I don't know how to fix it
Later I changed the nvidia driver to nouveau and it was worse because now only a black screen appears to log in and when logging in I access a terminal, I don't know what commands to use in case there are any to solve these problems.
Best Answer
Had the same problem, found a solution here on askubuntu and it worked for me! Ubuntu 18.04 audio disappeared after update
tomas reported that after adding a boot parameter to grub, their audio was restored. https://askubuntu.com/a/1218063/718497
Please upvote tomas if it helps. :-)
(I would've posted this as a comment, but my rep isn't 50 just yet)