External microphone not working

Solution 1:

My computer, compaq CQ45-118A, intel sound card.

Since ubuntu 10.04 to 11.04, I have added to /etc/modprobe.d/alsa-base.conf the following lines and worked for me:

options snd-pcsp index=-2

alias snd-card-0 snd-hda-intel

alias sound-slot-0 snd-hda-intel

options snd-hda-intel model=dell-m4-1

options snd-hda-intel enable_msi=1

options snd-hda-intel position_fix=1 enable=yes

Solution 2:

I found a solution, and uploaded a screencast to YouTube.

1. Install alsa-tools-gui package.
2. Run hdajackretask.
3. At the top, the Realtek analog codec will be already selected. In my case, it was Realtek ALC270.
4. Pay attention to the left panel (Pin configuration). In my case, it showed only 3 connected pins: Internal Mic, Internal speaker, Headphone. Note that it is missing a pin for the external microphone.
5. Check: ☑ Show unconnected pins.
6. Several new pins will show up at the left panel. For each one that is Not connected:
   • Check ☑ Override.
   • Look for a Microphone option at the drop-down box.
   • If there no Microphone in that box, then uncheck ☐ Override and try the next pin.
   • If there is a Microphone option, select it, and go to step 7.
7. You should now have one pin that was previously unconnected but now is overridden as a microphone. Click on Apply now and enter your password.
8. If you receive an error message about Device or resource busy, close any applications that are using the sound card (e.g. close alsamixer).
9. If you receive a success message: Ok, now go ahead and test to see if it actually worked!, do what it says and test it!
10. If it worked, click on Install boot override and enter your password again. If it did not work, uncheck ☐ Override and go back to step 6.

In my case, overriding pin 0x18 to Microphone fixed the issue for me.

Solution 3:

Had the same issue with Kubuntu 20.4. Tried unmuting it on alsamixer but tht didn't quite solve the problem.
As it turned out, Pulse Audio wasn't identifying the front panel because of the audio controller profile, so i googled a little bit and found this post and was able to solve the problem. Here goes a TL;DR:

• First open up Pulse Audio Volume Control by typing in a terminal: pavucontrol (if you don't have it installed, just do a: sudo apt install pavucontrol)
• On the Configuration tab, change the audio controller device to Analog Stereo Duplex.
• Go to the desired input/output device tab, plug your device into the front panel and identify wether your device is recognized or not. If it isn't, then the next steps might not solve your problem.
• As changes made in Pulse Audio's GUI aren't permanent, we have to make them this way by editing a pulse audio config file.
• In a terminal, type sudo vim ~/.config/pulse/default.pa. If you are not familiar with vi or vim, replace it with a text editor you are familiar with.
• Append the following strings to the configuration file:

### Set Built-in Audio (HDA Intel) profile to Analog Stereo Duplex
set-card-profile 1 output:analog-stereo+input:analog-stereo

• Save the file, reboot and enjoy you system!