Originally Posted by farslayer
I typically run alsaconf and let it reload all the sound modules to get it working properly again, but for some reason I'm thinking Ubuntu removed alsaconf from their modified version of Debian.
Maybe try sudo alsa force-reload
Sorry for the bump on old thread but just wanted to let anyone else know that has this problem that the sudo alsa force-reload
-command solved a nasty problem for me when after a update all my audio-hardware weren't showing up in audio preferences.
It took me a couple of hours googling to come up with this solution so this might boost it a bit