In the last few days I've been Googling all possible ways to fix this issue, and I've found the followings: I have a Windows on my laptop in dual-boot, and the sound is just fine there, so I believe it is not the fault of the hardware. I have checked with headsets, it is the same. The 'Sounds' settings only shop the option 'Dummy output'.
For a few days now, I can get no sound out of my Dell laptop on Ubuntu 18.04.4.
