The internal speakers in my laptop do not work. They are recognised by the system but they produce no sound. Headphones work normally.

I've actually found a solution that worked perfectly for a while (blacklisting snd_hda_codec_realtek, https://ubuntuforums.org/showthread.php?t=2443366), but it recently went back to silence, perhaps after a system update.

I've tried reinstalling alsa and pulseaudio and checking alsamixer but to no avail.