iMac G3 - No Sound

Hi and welcome to the group,
Does the iMac make any sound at all? Chime on boot? With all the sound levels moved up, any clinks, tinkles etc on clicking?
Was the sound working before?
If it's never worked the headphone jacks can be the problem. If it was sounds like a software issue.
Richard

Hello,

In the Output tab, "Internal Speakers" should be available and selected. If not, this could be your problem.

Maybe start up from an Mac OS or OS X disc and see if it makes any sound. Maybe some settings got corrupted. Otherwise I would be aiming at a bad speaker cable or it has come loose and needs to be reconnected, which has happened to me once.

Hope this helps,

-Brian

AOL's speaker cable suggestion makes sense also.
This can be a problem in the headphone board since there's a speaker cutout switch in there. I've worked on a lot of these and have seen 3 with bad headphone boards out of 25 I've worked on lately. I actually have one in right now but I'm on vacation and won't get back to it until the end of the month.
I had looked at some bad ones before and decided that resoldering was not an easy fix. I have some spares however and that seemed an easier way to go.
Check the headphone inputs are they loose and wobbly?
Richard

Your problems sounds like cracked or worn soldering in your headphone ports. I have the same problem on my machine, but stumbled upon a simple solution completely by accident.

This problem was confusing my iMac as to whether there were headphones plugged into the front ports. As I tried plugging my external speakers into various ports, I got short bursts of sound from the internal speakers. I realised that if I put a 3.5" plug halfway into the right-front headphone jack my speakers just started working again.

I think the problem is a dry joint or something of the sort. It causes the sound card to act as though there is a set of headphones plugged into the front-right headphone jack. Somehow, putting an old plug about halfway in may be completing a circuit (or something like that) and causing the sound card to revert to the default internal speaker setting.

I simply leave an old set of earphone hanging out of the headphone jack permanently. The internal speakers work, and I can still use external speakers with the sound-out jack on the side of the machine.

You might want to try this on the sound-out/headphone jacks on your machine. If you "plug up" one or more of them your sound might come back.

Hope this is helpful

Hi Shrimp

Back in February last year I posted a similar question. A perfectly happy mac suddenly lost its sound.
At the same time there were several other posts reporting the same thing.

I eventually concluded that it was a consequence of a system upgrade as I could find nothing physically wrong with the wiring or connectors.

The only difference was that mine had "headphones" selected in the output panel with nothing else available to change it to.

As it happened it wasn't an issue as I wasn't using the machine for anything other than as a server.

If you do get it cracked please post back as I would like to know what happened.

cheers
Donna

Well I just fixed my daughters sound (kept bugging me) and another one I have here for donation.
Symptom: no sound, no headphones front or side. Solution: pulled front headphone board, had to remove bottom, front outer bezel. Remove connector, desolder board from frame (4 points). Board removes foreward so have to bend inner bezel to do this. Loosening CRT bolts helps but cracked a bit.
Close examination showed multiple cracks between headphone jack pins and circuit board traces.
Mixed up some 15 min. epoxy and made a "fillet" around the board edge of the jack housing on the front of the board. Now that ain't goin' nowhere.
Carefully scraped insulation from traces and across cracks between pins and board until shiny copper. Formed solder bridges across cracks (too lazy to imbed wires or use a repair kit - expensive). Checked connections with continuity meter.
Reinstalled works fine.
Upon resoldering noted that the traces were pushed up ~ 1/16" and broken pieces were hanging on the pins at the failure point. Must have been manufactured that way so pressure or bumps on the front protruding headphone housing would break those traces.
Reinstalled - Works fine! 8 year old daughter can now hear Club Penguin. "Yah"
Richard