Audio line out buzz, clicks and ground hum all of the sudden?

Question

I've developed a nasty, sharp, buzzing from my audio line-out on my iMac G5, and it's gets twice as loud and unbearable when I put the computer to sleep. When I plug in a pair of iPod headphones and play a song, NO AUDIO WHATSOEVER appears in the phones, just a steady endless series of audible clicks. All connections were tested with new cables, etc., and it didn't make a lick of difference. My guess is that this issue has something ot do with the "optical out" dual-purpose jack 3.5mm jack, like it's internal switch is stuck half-on or something-- I saw a red light when plugging in the audio cable. Has anyone experienced a problem like this on their machine?

Answer 1

I've read about the red light here before. The jack does indeed read the impedence and then ping software to let it know something's attached. Perhaps try several different plugs in addition to the cables you've already tried. I know some speakers and headphones here at my place have WAY different impedence values.
Some people have been able to trouble shoot by creating a dummy user account to verify it's a software problem (the problem is gone in the new account). Other people have been successful resetting the core audio by running the GarageBand program. Not sure these tricks will help you, as 60 cycle hum leads me to think there's a hardware problem.
Let us know if this is helpful (as I only need 5 more points to hit 1000!)
Ed