Solution when HDMI audio output is not possible on Ubuntu 20.04.1 LTS

Symptoms

I usually connect my own PC to an external monitor and operate it on Ubuntu. Audio is output from the monitor via HDMI. However, the sound stopped coming out a few days ago. When I check Sound in Setting, HDMI cannot be selected in Output Device, or it does not appear. Only Digital Outputs (S / PDIF) can be selected. When I google it, it seems to be a common problem from long ago. The information was out of date and some methods didn't work, so make a note of the methods you were able to solve.

environment

PC: Homebrew PC CPU: Ryzen5 3600 Graphics board: NVIDIA GeForce GTX 1660 OS: Ubuntu 20.04.1 LTS

Reference site

Install NVIDIA driver on Ubuntu 18.04

solution

Rather, it's a reference site. Thank you @kannkyo: bow_tone1:

1. Check the drivers with sudo ubuntu-drivers devices

$ sudo ubuntu-drivers devices
== /sys/devices/pci0000:00/0000:00:03.1/0000:09:00.0 ==
modalias : pci:v000010DEd00002184sv000010DEsd00001324bc03sc00i00
vendor   : NVIDIA Corporation
model    : TU116 [GeForce GTX 1660]
driver   : nvidia-driver-435 - distro non-free
driver   : nvidia-driver-450 - distro non-free recommended
driver   : nvidia-driver-418-server - distro non-free
driver   : nvidia-driver-450-server - distro non-free
driver   : nvidia-driver-440-server - distro non-free
driver   : xserver-xorg-video-nouveau - distro free builtin

2. Install the driver with sudo ubuntu-drivers autoinstall

$ sudo ubuntu-drivers autoinstall

Then the NVIDIA driver will be installed automatically

3. Select HDMI from Output Device in Sound of Settings

Now you can safely output audio via HDMI.

I was impatient that the sound suddenly stopped, but I don't know the reason. Did the driver update and cause a problem because you are doing sudo apt update frequently? Anyway, it was good that installing the NVIDIA driver solved the problem.