I think you should check the output socket. It sounds as though it is not properly resetting when you take the external line plug out. Hence isolating the internal speaker. It is generally the spring contact not properly reseating, due either to mechanical failure aka breaking, or dirt on the contacts.
hope this helps robin On 13/11/2009, at 11:24 AM, KEVIN Lock wrote: > > I am refurbishing a couple of G4 Towers and suddenly the built-in speaker is > not producing any sound....startup chime or iTunes. The sound is fine when I > attach external speakers. > > At this stage I am thinking it is a piece of software I have loaded on both > machines?. > > I will check the software extras on both machines, but meanwhile, has anyone > experienced similar before? > > Thanks, > > Kevin > > > -- The WA Macintosh User Group Mailing List -- > Archives - <http://www.wamug.org.au/mailinglist/archives.shtml> > Guidelines - <http://www.wamug.org.au/mailinglist/guidelines.shtml> > Unsubscribe - <mailto:wamug-unsubscr...@wamug.org.au> > -- The WA Macintosh User Group Mailing List -- Archives - <http://www.wamug.org.au/mailinglist/archives.shtml> Guidelines - <http://www.wamug.org.au/mailinglist/guidelines.shtml> Unsubscribe - <mailto:wamug-unsubscr...@wamug.org.au>