Built-in speakers not showing in sounds or System profiler

Question

Hi all,
I've just bought a 2nd hand eMac 1Ghz model. Having logged in and checked over the installed software (just the basics) and connected to my home network, I tried starting up iTunes to listen to internet radio. I noticed that there was no sound, although I hadn't noticed the lack of startup chime! First thing I checked was the volume, which was set to max, and then popped in headphones - which work. I checked the options in Sound and noticed that all that is listed for the devices is the headphones. After a bit of searching online I found suggestions to Archive and Repair OS X, which didn't solve the problem, I then did a clean install of OS X and used the System Restore discs that came with the eMac to re-install all the software. Again, no joy. After another search online I spotted a suggestion here regarding System Profiler, so I checked this and found that there is no Audio listing under Hardware.
Can anyone suggest what I can try to get the speakers appearing, and working again? I'm a bit of a novice with Macs, although I've worked on a G5 previously, this is the first Mac I've owned! With a PC I'd expect it to be a case of a loose soundcard, but I haven't the foggiest where to start looking inside a Mac!
Thanks in advance!

Answer 1

This is a long shot. On some Mac laptops, an out-of-spec phono-plug can jam a contact within the jack in the "mute speakers" position and exhibit the symptoms you've described. The first check is to shine a light into the jack to see if there is a foreign object present.
Although the affected jack on the notebooks is a newer technology, you might try the lo-tech fix that usually works on the newer units: insert a standard mini-plug and GENTLY wiggle the plug in the horizontal plane. If that doesn't restore sound when you remove the plug, try the same thing but wiggle in the vertical plane. Last is to wiggle the plug in a circular motion.
Worth a try. The fact that the headphones work pretty much precludes the sound hardware (soldered to the logic board) from being the culprit. You may find that using a cheap set of external speakers is the better-sounding option and MUCH easier than taking an eMac apart. I have a pair of "no-name" speakers I picked up for US$2 at a yard sale that are far better than the little internal speakers.