Ubuntu 20.04 - Internal microphone not working

The built-in microhone from my laptop does not work. When I introduce an external microphone, that external one does work so it seems to be an issue with the internal one only.

I'm on Ubuntu 20.04, fresh install. My laptop is Asus X550LD.

I've tried few possible solutions: 1) installed pavucontrol to check if the micro was muted but was not, also not responding there; 2) installed vokoscreen to make an audio recording, can only hear noise, not my voice; 3) in pavucontrol I tried to mute the "front right", also did not work (some users recommended to try this).

I know that the microphone itself is ok because I've just changed OS and it was working before.

This is my hardware:

sudo lspci -knn | grep Audio -A3
00:03.0 Audio device [0403]: Intel Corporation Haswell-ULT HD Audio Controller [8086:0a0c] (rev 09)
    Subsystem: ASUSTeK Computer Inc. Haswell-ULT HD Audio Controller [1043:131d]
    Kernel driver in use: snd_hda_intel
    Kernel modules: snd_hda_intel
00:04.0 Signal processing controller [1180]: Intel Corporation Haswell-ULT Thermal Subsystem [8086:0a03] (rev 09)
--
00:1b.0 Audio device [0403]: Intel Corporation 8 Series HD Audio Controller [8086:9c20] (rev 04)
    Subsystem: ASUSTeK Computer Inc. 8 Series HD Audio Controller [1043:11af]
    Kernel driver in use: snd_hda_intel
    Kernel modules: snd_hda_intel
00:1c.0 PCI bridge [0604]: Intel Corporation 8 Series PCI Express Root Port 1 [8086:9c10] (rev e4)

At the command line, type alsamixer

Make sure levels are up. There's a line near the top called "view", which tells you what F-key to press for capture devices.

You should at least see the internal mic listed there. If you do not, there's a driver problem. It may be that it does not have levels but does have a "mic boost". You might try turning that up a bit.

If you do see the mic in alsa, but it's not available to pulseaudio, there's an issue with your pulseaudio configuration.

Internal mics are often very low quality, so it may be that you would end up using the external mic anyway.