No speakers, no microphone, but headphones @Dell Lattitude E6530 (20.04)

Run hdajackretask and select the codec at the top. If you don't see the devices you are looking for, select Show unconnected pins in the options. If you see the devices now, you should be able to select Override to enable them. I had to do this to get the jacks working on my docking station. You can press Apply Now to test it, and Install boot override to commit it.

Please restart alsa driver

sudo alsactl -F restore 

It might be the one of the reason.

Have you tried installing drivers for that? It happened to me on Debian. Install the necesarry firmware. (e.g. package firmware-realtek).

Try this :

sudo apt-get install rhythmbox clementine

or

sudo apt-get install --reinstall rhythmbox clementine

then reboot, in case there is still no sound.

To check if your system has access to HDMI open a terminal and execute:

aplay -l

This should give you a list like:

 card 0: NVidia [HDA NVidia], device 0: ALC1200 Analog [ALC1200 Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
 card 0: NVidia [HDA NVidia], device 3: ALC1200 Digital [ALC1200 Digital]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
 card 1: NVidia_1 [HDA NVidia], device 3: HDMI 0 [HDMI 0]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
 card 1: NVidia_1 [HDA NVidia], device 7: HDMI 0 [HDMI 0]
   Subdevices: 0/1
   Subdevice #0: subdevice #0
 card 1: NVidia_1 [HDA NVidia], device 8: HDMI 0 [HDMI 0]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
 card 1: NVidia_1 [HDA NVidia], device 9: HDMI 0 [HDMI 0]
   Subdevices: 1/1
   Subdevice #0: subdevice #0

In your case I'd expect some HDMI devices. If these are not available, then it is a driver problem - pulseaudio needs the data from alsa, so if alsa can't see it, pulseaudio can't either.

If those devices exist, issue

pactl list sinks

in order to check out which devices will accept audio signals. In such cases I usually rely on installing pavucontrol which is the UI friontend for pulseaudio.

There you can select the devices needed:

EDIT

After the OP posted the necessary output some hints:

1. alsa can see the cards. So they exist and could be used.
2. Pulseaudio does NOT recognize them.

This can be seen in the sinks lists as well as in pavucontrol. Still not clear if pulseaudio recognized the cards or not. The output of

pacmd list-cards

would be helpful.

One way to test is to check all the cards (in case list-cards delivers something) by doing:

speaker-test -D hw:HDMI,N -c 2 -r 48000

If one of those tests work (iter thru all cards you have, c is the card number) try to connect it with pulseaudio (the output MUST be listed in the pacmd list-cards list:

pacmd set-card-profile alsa_card.pci-0000_00_1b.0 output:hdmi-stereo-extra1

Both commandlines are examples, just to give you the gist: You need to test which cards are working, then you link the alsa information to the working/desired output of pulseaudio.

I had this issue when i upgraded to Ubuntu 20.04. check your python version, if it is above Python v3.8 then some time API methods are deprecated. In the

FIX : Update the function "time.clock()" in pulseaudio.py file with "time.perf_counter()" in all the occurrences

please find related issue and solution in this thread for Kazam application

I had this problem with 16.04 and started working with 20.04 after updating the BIOS. If you see HDMI sound devices appearing and disappearing then update your BIOS. Is very easy to update, you download the .exe file from the Dell website and you copy it to your EFI partition. I created a folder and copied it to /boot/efi/EFI/Dell/Bios/ Then you boot and press the right key (F2 or F12) to stop the boot process and select BIOS upgrade that will allow you to chose the downloaded file.