Primary sound card not detected by alsamixer

I installed Ubuntu 20.04 on my PC. My screen has built-in speakers. Sound is only coming via the speakers of my screen which is connect via HDMI. They are not powerful enough and I want to connect my speakers to the master output. On the sound setting I have no other output option and Ubuntu is unable to recognize my native sound card even on alsamixer.

This is the output of lspci -v | grep -A7 -i "audio":

00:1f.3 Multimedia audio controller: Intel Corporation Cannon Point-LP High Definition Audio Controller (rev 30)
    DeviceName: Onboard - Sound
    Subsystem: Intel Corporation Cannon Point-LP High Definition Audio Controller
    Flags: bus master, fast devsel, latency 32, IRQ 139
    Memory at a1338000 (64-bit, non-prefetchable) [size=16K]
    Memory at a1000000 (64-bit, non-prefetchable) [size=1M]
    Capabilities: <access denied>
    Kernel driver in use: snd_hda_intel
    Kernel modules: snd_hda_intel, snd_sof_pci

aplay -l:

**** List of PLAYBACK Hardware Devices ****
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

At the end of my /etc/modprobe.d/alsa-base.conf:

    # Prevent abnormal drivers from grabbing index 0
    options bt87x index=-2
    options cx88_alsa index=-2
    options saa7134-alsa index=-2
    options snd-atiixp-modem index=-2
    options snd-intel8x0m index=-2
    options snd-via82xx-modem index=-2
    options snd-usb-audio index=-2
    options snd-usb-caiaq index=-2
    options snd-usb-ua101 index=-2
    options snd-usb-us122l index=-2
    options snd-usb-usx2y index=-2
    # Ubuntu #62691, enable MPU for snd-cmipci
    options snd-cmipci mpu_port=0x330 fm_port=0x388
    # Keep snd-pcsp from being loaded as first soundcard
    options snd-pcsp index=-2
    # Keep snd-usb-audio from beeing loaded as first soundcard
    options snd-usb-audio index=-2

This is what my alsamixer is showing if I try to select another sound card:

I am aware my question is a duplicate but I tried many suggestions on the web none of which worked for me.

The second Card should also be listed/loaded. For the not wanted HDMI-Devices I used the module pci_stub to claim the Audio-Device before the snd-modules are loaded. After adding the line you have to execute update-initramfs -u if i remember correctly.

To use the pci_stub-Module on your not wanted Soundcard, you have to get the PCI-Vendor-Info with lspci -nn. In my Case this was the following

lspci -nn |grep -i audio
01:00.1 Audio device [0403]: NVIDIA Corporation TU116 High Definition Audio Controller [10de:1aeb] (rev a1)
06:00.0 Audio device [0403]: Creative Labs Sound Core3D [Sound Blaster Recon3D / Z-Series] [1102:0012] (rev 01)

As i want to get rid of the 'Audio Card' from my GPU the wanted ID is "10de:1aeb". You then put the pci_stub ids=10de:1aeb in the File /etc/initramfs-tools/modules.

The listet modules in that File will be loaded' before automatic Module-Loading where a device ususally gets the correct module/driver. The ids=10de:1aeb or in your case some other String is needed so that the correct PCI-Card will be chosen(i think it doesn't even work without) which then ,through the pci_stub-module, will be blocked from 'auto-loading' the correct 'snd-*' module. And therefore no /dev/snd/hwXYZ-Device will be created and alsa won't recognize it as a Sound-Card.

lspci -s 01:00.01 -v
01:00.1 Audio device: NVIDIA Corporation TU116 High Definition Audio Controller (rev a1)
    Subsystem: Gigabyte Technology Co., Ltd TU116 High Definition Audio Controller
    Flags: bus master, fast devsel, latency 0, IRQ 10, IOMMU group 1
    Memory at df080000 (32-bit, non-prefetchable) [size=16K]
    Capabilities: [60] Power Management version 3
    Capabilities: [68] MSI: Enable- Count=1/1 Maskable- 64bit+
    Capabilities: [78] Express Endpoint, MSI 00
    Capabilities: [100] Advanced Error Reporting
    Kernel driver in use: pci-stub
    Kernel modules: snd_hda_intel

Here you can see the 'Kernel driver in use'

And as a result of blocking the NVIDIA-CARD i got only one Card recognized

aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: Creative [HDA Creative], device 0: ALC898 Analog [ALC898 Analog]
  Subdevices: 0/1
  Subdevice #0: subdevice #0

It isn't directly your problem but maybe it helps. :-)

In my Case Sound worked, but Switching the Hardware-IDs around for alsa and things like that... ..*******.. my Displays don't even have Speakers..