iMac Randomly Kicks on Internal Speekers

[Big Bone]

When I'm using my external speakers my iMac while listening to iTunes it will at random kick off the external speakers and into internal speakers then back again.

Any idea what would cause this. I suppose it could be the speakers but I don't see how.

Here's the info:
iMac 3.06 Intel Core 2 Duo running Version 10.6.8


Thanks in advance.

 

[Bear]

...
Any idea what would cause this. I suppose it could be the speakers but I don't see how.
...

The only time I've seen something like this happen is with USB speakers since if the system thinks they were disconnected, it resets back to the internal speakers.

 

[Big Bone]

These are not usb speakers, they just plug right into the headphone jack.

 

[Richdmoore]

Try to isolate the problem by using headphones (or another set of speakers & cables.) It could be a bad jack on the iMac, or maybe a break in the speaker wire/plug itself. Either way, if it reoccurs with headphones, you know it's the iMac and not the speakers, if it stops, I would investigate the wire or speaker plugs.

 

[DrewJM]

My bet is that it's a problem with the jack.

It would seem the computer thinks you've unplugged your speaker system, therefore switches on the built in speakers.

Have you tried wiggling the input gently? If the speakers switch while your doing this, the jack may be going bad (or already bad).

If nothing happens while you are doing this and the problem seems to stop, the jack may be on the fritz but you just jiggled it to a good spot that will hopefully go untouched for a while and you'll be in good shape.