Ubuntu 20.04 Dell Inspiron 3000 on-board audio not being detected

This is a fresh install of 20.04 on a Dell Inspiron 3000.

The system will detect an external headset and hdmi as an output/input, however, it will not detect the internal speakers/mic.

Kernal - 5.12.10-051210-generic

Sound driver - Advanced Linux Sound Architecture Driver Version k5.12.10-051210-generic.

    Subsystem: Dell Raven/Raven2/Fenghuang HDMI/DP Audio Controller
    Flags: bus master, fast devsel, latency 0, IRQ 76
    Memory at c06c8000 (32-bit, non-prefetchable) [size=16K]
    Capabilities: <access denied>
    Kernel driver in use: snd_hda_intel
    Kernel modules: snd_hda_intel

04:00.5 Multimedia controller: Advanced Micro Devices, Inc. [AMD] Raven/Raven2/FireFlight/Renoir Audio Processor
    Subsystem: Dell Raven/Raven2/FireFlight/Renoir Audio Processor
    Flags: bus master, fast devsel, latency 0, IRQ 69
    Memory at c0680000 (32-bit, non-prefetchable) [size=256K]
    Capabilities: <access denied>
    Kernel driver in use: snd_pci_acp3x
    Kernel modules: snd_pci_acp3x, snd_rn_pci_acp3x

04:00.6 Audio device: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 10h-1fh) HD Audio Controller
    Subsystem: Dell Family 17h (Models 10h-1fh) HD Audio Controller
    Flags: bus master, fast devsel, latency 0, IRQ 77
    Memory at c06c0000 (32-bit, non-prefetchable) [size=32K]
    Capabilities: <access denied>
    Kernel driver in use: snd_hda_intel
    Kernel modules: snd_hda_intel 

Running alsamixer shows two options of 0 HD-Audio Generic and 1 HD-Audio Generic, but none of these seem to do anything.

Any ideas on where to look next would be greatly appreciated, thanks.

I suggest you try the following (source).

1. Edit /etc/default/grub

   $ sudo nano /etc/default/grub
   

   Find the line starting with GRUB_CMDLINE_LINUX_DEFAULT and append snd_hda_intel.dmic_detect=0.

   (An alternative option snd-intel-dspcfg.dsp_driver=1 was proposed, you may try whatever works.)

2. Update grub configuration with

   $ sudo update-grub
   

3. Reboot

I expect this to work, compare audio specs of the system in the source OP and the present one. It is worth reading the other answers and comments in the same question.

You might be getting the same result with

$ echo "options snd-hda-intel dmic_detect=0" | sudo tee -a /etc/modprobe.d/alsa-base.conf

(or the alternative

$ echo "options snd-intel-dspcfg dsp_driver=1" | sudo tee -a /etc/modprobe.d/alsa-base.conf

as per item 1 above)

If the above doesn't work, further info on your system may help. Please post the exact output of all the commands listed in Only "Dummy output" (sound) in Ubuntu 20.04 after reboot - Broken driver / module (and, to be sure, the commands themselves as you wrote them).

Related:

1. https://bbs.archlinux.org/viewtopic.php?id=251157
2. Ubuntu 19.10 Audio driver issue
3. https://forums.linuxmint.com/viewtopic.php?t=314511
4. No sound in built in speakers just "dummy output" as output device
5. https://bugzilla.kernel.org/show_bug.cgi?id=205959