Output says built in audio but only headphones as an option??!!

Question

Every where I've read and researched they've said that the round Apple Pro Speakers M6531 are supposed to be able to work with the iMac G4. I have a iMac G4 (1GHz Flat Panel) with the mini jack port and my Apple Pro Speakers still won't work on it. I used to have some Logitech external speakers I hooked up to the headphones port and the sound worked fine, but now nothing through the Pros when I hook it up to the mini port. In system pref, under sound output, it's showing external speakers just the headphones and it's the only option that's available. I tried to reset the pram but nothing and I reset the PMU and still no sound. Is there any other way, something I haven't tried yet that can make those speakers work. I would hate to have to buy an expensive adapter only to have it still not work. I'm not cheap, I'm just confused...I supposedly have the right computer to play my speakers, so why isn't it working like it should. Help please!!!

Answer 1

If the Pro speaker's jack or plug is not firmly seated, the external Apple speakers
will not work. And if the port or plug is damaged, they probably won't show or work.
I have a few of these iMac G4 1.25 17" computers with the Pro original speakers and
the port they use is a specialized and marginal one. It is possible the plug is not in
the port snugly or perhaps one or the other is damaged.
Does the System Profiler> Audio show all the normal supported sound ports? While
it may still show defective items since they'd be present, it may also be possible the
ones you should see there may be missing when they've stopped working properly.
Not sure if the standard Apple Hardware Test included with the computer could have
a test report capability in regard to showing defects in this circuit, if only the plug-in.
And in a few cases, if the mini audio port has sustained some damage to its own tiny
switching mechanism, the computer may be seeing the headphones as the only audio
available simply due to this one factor. These have been known to stick in the non-
default position and sometimes by carefully inserting and removing (or turning, too)
the plug into the mini-port, aka the headphone jack, it may cause the tiny switch to
release & return the normal audio-out to be seen: external speakers would reappear.
And if both the standard mini audio port and the Apple pro speaker port both fail to
work, there may be a problem on the sound or audio circuit, supporting them both.
But, if the single internal speaker does work, then all is not lost in that case; though
a repair may be required, I am not sure at this time what that may entail or cost.
For some applications, there had been a special audio adapter where the Pro speakers
could be used with other Apple computers, but these speakers require amplification
and a standard speaker jack by itself does not support that kind of audio power output.
Hopefully this helps somewhat...
Good luck & happy computing!