I tried Ubuntu Vanila, Mate and Kylin (all same version 20.04) still the same. It plays fine with the inbuilt speakers but when a headphone is plugged in there is no audio. In the speaker settings it changes from speaker to headphones but doesn't play. Then reinstalled 19.10 and now audio is fine.
Try in your terminal
sudo apt update && sudo apt install alsamixer
alsamixerin your terminal.
- press arrow right til you go to HEADPHONES bar.
- press up/down to adjust the volume.
- press Esc to exit alsamixer.
sudo alsactl storein your terminal to store your settings earlier.
Ubuntu, headphone not muted in 'alsamixer', volume is high, still now sound!
Please try this, if your Ubuntu is using
snd hda intel.
Open Terminal (If you don't know where Terminal is, click Show Application in Unity, type Terminal, it should appear, click it open.)
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.
Inside etc folder, find modprob.d folder.
In modprobe.d find the file alsa-base.cof (or alsa.conf instead, if alsa-base.conf is not there.)
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
Click 'Save' in alsa or alsa-base.
Restart the system. Plugin your headphone, microphone.
Now Ubuntu should be able to auto-detect headphone and microphone.
After installing Ubuntu 20.04 LTS on my new Dell Vostro 3490 (2019) my 3.5 mm audio jack was not working. This is what worked for me:
- Make sure Headphones built-in audio is selected in Ubuntu's Sound Settings in the Output panel.
- Run alsamixer to unmute the headphone audio (as in @tanhernandez answer):
- Save alsamixer settings:
# sudo alsactl store
# lsactl restore