Previous 1 2 3 Next 34 Replies Latest reply: Dec 15, 2010 3:26 PM by fox7
atmcclain Level 1 Level 1
I received my new display last week - was working great, including the sound. Now, I can't get any audio output out of the display at all. (Switching to the built-in internal speaker works fine, so I know it's not a general issue.) I installed the relevant software update soon after plugging in the display.

This seems like a software issue to me because some other things are weird. When the audio output is set to Display Audio, changing the volume up and down is very slow instead of instant. It actually takes a few seconds to register the up or down volume keypress. If I drag the volume slider in system preferences > Audio, I even see the wheel icon spinning for a while. Although no volume setting results in any sound output.

I restarted the computer and unplugged / replugged both the mini display port and the USB connection. Any ideas?

(The display part works fine, BTW!)

Thanks - ATM

Mac Mini (not the latest one but one generation previous), Mac OS X (10.6.4)
  • lacroixdesign Level 1 Level 1
    I am having the same problem. Has anyone else run into this and come up with a solution?
  • reichea Level 1 Level 1
    Try this - it has worked for my sound issues with my new 27" ACD:

    Delete the from the MAIN LIBRARY>PREFERENCES - (not the users library PREFERENCE folder).

    Again, in the same MAIN LIBRARY>PREFERENCES folder, go into the AUDIO folder and delete and

    Reselect the sound device you want as your default in the Sound Preference Pane.

    Restart your computer.

    None of this will harm your system, but hopefully it will solve your problem.
  • atmcclain Level 1 Level 1
    Hi Reichea:

    Thanks for the suggestion. I did not have the first file anywhere on my system (that I could find - not in the Mail Library > Preferences folder). I did have the second two files within the audio subfolder. I deleted those and restarted, but unfortunately it did not resolve my problem.

    A bit more detail - the display's microphone also appears NOT to work. The built-in iSight and USB hub are OK, however.

    Thanks - ATM
  • reichea Level 1 Level 1
    Sorry to hear that. Do you have an Apple Store near you? I would take it there and have them test it, or maybe even take your whole system in and let them make it work for you.
  • atmcclain Level 1 Level 1
    The sound isn't crucial for me now, so I'm going to wait a few days and see if any news pops up. I wouldn't be surprised to see a software update on this soon (if I'm right that it's some weird bug and not something I'm just missing).
  • fox7 Level 1 Level 1
    The following, restored audio for my new 27" display:

    - shut down your mac
    - unplug the power cord from the display
    ...wait 20 seconds...
    - plug in the power cord for the display
    - start up your mac

    -> audio should be restored to your 27" display
  • pdxgoat Level 1 Level 1
    fox7's technique worked for me.
  • atmcclain Level 1 Level 1
    Great! This worked for me too. Thanks very much - I suppose it needed some kind of 'hard reset.'

    Marked as answered - unless of course the problem comes back...

    Appreciate it greatly - Anselm
  • Mictons Level 1 Level 1
    I have been experiencing the same problem, I can unplug the monitor power to get the sound to return but after a day or two I check and it is gone again, I have been fighting this problem for a couple of weeks and am going to make a trip to the Apple Store to see if I can get a permanent fix.
  • pdxgoat Level 1 Level 1
    Yep, unplugging was only a temporary solution for me also. Seems like we need a software update from Apple.
  • basictheory Level 1 Level 1
    I'm having similar problems. Display audio, microphone and iSight camera all have issues. Tried to reset the audio preferences but I'm still having issues days later. Wondering if I should exchange it or wait for a software fix?

    Message was edited by: basictheory
  • Daniel Genser Level 1 Level 1

    +1 on needing a software update. I downloaded the software update released on September 22 (described at but I'm not seeing the new "LED Cinema" listing in my sound preference pane as seen below:

  • atmcclain Level 1 Level 1
    Hi Daniel:

    I'm not positive about this, but I believe the "LED Cinema" option will only display if your Mac outputs audio through the mini display port. I believe only the newest generations of Macs do this, where as my (one generation old) Mac Mini does not.

    Do you have "Display Audio | USB" as an option? That should be equivalent - it's just that the display is using the USB connection to run audio instead of the display port. The issue in this thread is that sometimes that fails and the display needs to be un/re-plugged to get it working again. Maybe they didn't test the USB audio option as thoroughly as the display port option.

    I, too, found that screenshot on the support page confusing, BTW.

    Best - ATM
  • melduforx Level 1 Level 1

    I'm having the exact same issues as the OP. I can get it to come back temporarily by using the "down volume" key on the keyboard, but switching around in apps makes the sound drop out.
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