I posted this about 6 weeks ago, got some replies but never was able to resolve the problem.
Our G4/500 used for DTP work was hooked up to a set of external speakers, and worked fine. We pulled the speakers for use somewhere else, reset the Sound settings, but no sound from the internal speaker. Checked and rechecked the settings, trashed the Sound pref file, zapped PRAM...nothing works.
I am truly stumped. Any and all help would be most appreciated.