Since several days ago (something automatically upgraded), I get no sound out of my Lenovo Thinkpad 470s laptop model 20HFCTO1WW with Ubuntu 18.04. I tried several things other similar threads suggested:
returns 0 cards
lspci -nnk | grep -A2 Audio
returns nothing, and
pulseaudio -k && sudo alsa force-reload
Q1: How do I get my sound back?
Q2: This seems like a fairly catastrophic defect that's not getting enough publicity -- does anyone know what happened in apt-get upgrade to have caused this? Is it "a part of the package" associated with a FOSS OS, i.e. its instability? As much as I dislike Windows, I can't recollect anything similar ever happening.
UPDATE 1: Ubuntu just auto-updated and the details of the update indicated Thinkpad-related updates. After that, the Settings don't show dummy output anymore and
pacmd list-cards and
lspci -nnk | grep -A2 Audio are no longer empty, however, there is still no sound coming out.
UPDATE 2: After removing the pulse config (
https://askubuntu.com/questions/1133074/after-dummy-sound-output-got-fixed-by-ubuntu-update-speakers-work-but-not-headp), I get sound but only coming out of the speakers. When I plug my headphones, I get no sound.
UPDATE 3: I lost sound again, only
Dummy Output showing in Settings.