Special prize for me the other morning. Now and again (think every couple of months) Phonon (the KDE device manager) would, upon login, pop up a small box telling me that Analogue Output Something Something Whatchamathing is no longer need, do you want me to just remove it? As you can tell the specifics escape me now, I blame a rather sleep deprived night leaving me in an unfit state to operate anything more complex than a spoon. Normally I say no, look at it suspiciously and swear to “do something about that later”. I had a 50/50 chance of purely by chance choosing the correct option… I didn’t.
ALSA was clearly working, I could hear audio on the command line with mplayer, but KDE specific apps were just not having it. So after a very long search, several chicken sacrifices and blind luck I stumbled upon a fix allowing you to reset your Phonon config. Apparently the device is still there, you’ve just removed it from your normal users login.
So…. As YOUR user (ie. not root) run the following commands:
rm $(kde4-config --localprefix)/cache-$(hostname)/libphonon/hardwaredatabase
rm -r ~/.config/kde.org
rm -r ~/.xine
Logout of KDE and back in and you should have working audio again. Alas I can’t remember where I got the fix so I hear-by claim this to not be my own work but perhaps useful to other dexterity challenged individuals.