I can confirm the constant red light of the optical port, this is normal with ANY optical audio port, not just those on the G5. If you have any home theater or stereo equipment with optical out, it will be lit all the time too.
I agree with what another poster said about there being something wrong with the rear port that makes the system think there are speakers plugged in and thus the internal is diasabled. If you do some googling you should find some potential fixes. Chance -- You received this message because you are a member of G-Group, a group for those using G3, G4, and G5 desktop Macs - with a particular focus on Power Macs. The list FAQ is at http://lowendmac.com/lists/g-list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to g3-5-list@googlegroups.com For more options, visit this group at http://groups.google.com/group/g3-5-list