12.10: sound DOES work, mute button, not so much
I'm trying Lubuntu 12.10 on an iMac G3 600MHz SE, and I had sound on the first go, but later the sound stopped working.
After trying the solution posted here:
I realized that I was down the wrong path. The problem was I had muted the sound just before the problem started, and now I see that the problem is the GUI Mute button on the LXDE desktop: I have filed a bug report.
Read the details here:
Basically, don't mute the volume using the GUI checkbox for Lubuntu on an iMac, or you won't get audio back when you uncheck it.