I'm using Ubuntu 18.04 on a Dell Inspiron 13. My built in speakers and audio jack aren't reproducing any sound. Bluetooth speaker does work. However, when I check sound settings, pulse audio, and the alsa mixer, everything seems to be detected and in order (volume bar on pulse audio is moving with the sound, alsa mixer detects my sound card, when I plug in headphones I get the Select Audio Device prompt, etc), so I know this isn't a dummy output issue. I get this from sudo aplay -l:
**** List of PLAYBACK Hardware Devices ****
card 0: PCH [HDA Intel PCH], device 0: ALC3253 Analog [ALC3253 Analog]
Subdevices: 0/1
Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 3: HDMI 0 [HDMI 0]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 7: HDMI 1 [HDMI 1]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 8: HDMI 2 [HDMI 2]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 9: HDMI 3 [HDMI 3]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 10: HDMI 4 [HDMI 4]
Subdevices: 1/1
Subdevice #0: subdevice #0
I tried tomas's solution to Ubuntu 18.04 audio disappeared after update and it worked until my laptop went to sleep, then the problem returned. I made it permanent after it worked using htorque's answer to How do I add a kernel boot parameter? The changed command lines are still there in the kernel boot parameter and the GRUB configuration file, so I don't know why it stopped working. I would appreciate any help with fixing this problem.
P.S. Not sure if this matters, but the problem began after an update on 16.04. After I couldn't fix it, I installed 18.04, but the problem persisted, which is when I found that temporary solution I linked to above.
pavucontrolif card is muted. – Michal Przybylowicz May 05 '20 at 15:29