Two days ago I upgraded my Ubuntu Linux 18.04 LTS Workstation to Ubuntu 20.04.1 LTS and I experienced some audio problems.
Basically I noticed that the system was not playing any sound.
When I checked the audio config I noticed that only the external output of my motherboard was detected, but not the HDMI output from the monitor.
I have a 28″ Asus monitor with speakers embedded.
It didn’t make any sense, so I decided to restart pulseaudio:
That fixed my problem.
However I noticed that when I lock my session, and so the monitor goes off for power saving my HDMI monitor output disappears from the list again.
Repeating the command pulseaudio -k will fix that again.
I checked that the power saving was enabled:
I had 1 and Y.
To make the change permanently, I change the power mode settings:
sudo sh -c "echo 0 > /sys/module/snd_hda_intel/parameters/power_save"
sudo sh -c "echo N > /sys/module/snd_hda_intel/parameters/power_save_controller"