How to fix 3.5 mm audio jack not working after upgrading to 20.04

Try in your terminal

• sudo apt update && sudo apt install alsamixer
• run alsamixer in your terminal.
• press arrow right til you go to HEADPHONES bar.
• press M to unmute.
• press up/down to adjust the volume.
• press Esc to exit alsamixer.
• run sudo alsactl store in your terminal to store your settings earlier.

Use pavucontrol and enable the microphone audio (and speaker). If the microphone is disabled the speaker doesn't work.

I don't know why this happens, but the above fixes the problem.

Ubuntu, headphone not muted in 'alsamixer', volume is high, still now sound!

Please try this, if your Ubuntu is using snd hda intel.

1. Open Terminal (If you don't know where Terminal is, click Show Application in Unity, type Terminal, it should appear, click it open.)

2. In Terminal type the command, sudo nautilus. Give your password as asked. This should have opened your file browser with access to root filesystem. Look for etc folder.

3. Inside etc folder, find modprob.d folder.

4. In modprobe.d find the file alsa-base.cof (or alsa.conf instead, if alsa-base.conf is not there.)

5. Copy the following two lines and paste as the last two lines in alsa configuration file you have just opened.

options snd-hda-intel model=headset-mode
options snd-hda-intel model=dell-headset-multi

6. Click 'Save' in alsa or alsa-base.

7. Restart the system. Plugin your headphone, microphone.

Now Ubuntu should be able to auto-detect headphone and microphone.