Sorry for the off-topic post but a friend in Greece is needing advice. All ideas are welcome. Thanks! I have a problem with the sound on my iMac 17”Flat Panel 1Ghz Super Drive -OS 10.2.5 I have had this new machine for about 6 weeks. The Pro Speakers had worked really well and still do. My problem is that one day last week suddenly only one speaker worked when I played a CD. I was able to fix this in the Sound Preference Output panel by centering the stereo balance slider. For some reason the slider was way to the right. Next day the same problem except that Sound Preference Output panel had no stereo balance slider anymore. The startup chimes are in stereo (or at least sound comes from both speakers), yet everything else including modem dialling and alert sounds come from one speaker. I reset the PRAM and the firmware. I reinstalled System software starting with OS 10.2.3 then updated to 10.2.4 and then to 10.2.5. but still no stereo control in the Sound Preference Output panel. In the output panel the “device for sound output” is set at “Built-in audio controller” . But under “settings for selected device:” it says “There are no settings available for the selected device”. That’s where the stereo balance slider used to be. In the Apple website I found no evidence of anybody else having this problem. Can anyone propose a solution? Tom in Skopelos, Greece