Audio stopped working Ubuntu 19.04
Reinstall ALSA and PulseAudio
Try reinstalling ALSA and PulseAudio Manually that must be fix the problem for you.
Open your terminal, and enter the following commands:
sudo apt-get remove --purge alsa-base
sudo apt-get remove --purge pulseaudio
sudo apt-get install alsa-base
sudo apt-get install pulseaudio
sudo alsa force-reload
I don't have enough points yety to comment... have your tried this one? Sometimes my laptop audio goes off and this does the trick
pulseaudio -k
This problem has been going around a while. I have a ASUS UX433FN with a Realtek ALC294 chip. From other threads it sounds like this issue (for dual-boot PC's) seems to be a result of Windows 10's fast boot behavior. I've disabled this feature in Windows 10, doing a full shutdown, and this has seem to fix my problem. Not sure if it's a permanent fix however.
How to disable fast boot on Windows 10