27" Cinema Display Sound Issues

I was really hoping that the 10.6.5 update would resolve things but no luck.

Just happened to me again.

Very disappointed.

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I bought the 27" display last Saturday. Sound stopped working on Monday. Powered down, unplugged, restarted and it was fixed. Happened again on Wednesday. Tried the restart with COMMAND OPTION+PR and that did not fix it. Powered down, unplugged, restarted and it was fixed.

Also noticed the pinwheel popping up when trying to change sound volume from keyboard and sluggishness whenever changing it from other locations.

Installed 10.6.5 hoping that would fix it early Thursday morning. Sound off again by 10:00 AM. Powered down, unplugged, restarted and it was fixed.

This is kind of a big issue - didn't realize it till the sound was gone. Can't watch podcasts, miss email and meeting alerts...

Trying the delete plist suggestion. Noticed changes are:
com.apple.audo.DeviceSettigs.plist
<key>AppleUSBAudioEngine:Apple Inc.:Display Audio:23565B02:2,1</key>
<key>controls</key>
array elt 1
<real>0.6103515625</real> --> <real>0.5625</real>
array elt 2
<real>0.6103515625</real> --> <real>0.5625</real>
com.apple.audio.SystemSettings.plist
Deleted
<dict>
<key>0</key>
<dict>
<key>current default system output device</key>
<string>AppleUSBAudioEngine:Apple Inc.:Display Audio:fd341000:2,1</string>
...
<key>501</key>
<dict>
<key>primary default output device</key>
<string>AppleUSBAudioEngine:Apple Inc.:Display Audio:23565B02:2,1</string>
<key>primary default system output device</key>
<string>AppleUSBAudioEngine:Apple Inc.:Display Audio:23565B02:2,1</string>
<key>secondary default output device</key>
<string>AppleHDAEngineOutput:1B,0,1,5:2</string>
<key>secondary default system output device</key>
<string>AppleHDAEngineOutput:1B,0,1,3:0</string>
</dict>
<key>89</key>
<dict>
<key>current default output device</key>
<string>AppleUSBAudioEngine:Apple Inc.:Display Audio:fd341000:2,1</string>
</dict>
<key>92</key>
<dict>
<key>current default system output device</key>
<string>AppleUSBAudioEngine:Apple Inc.:Display Audio:23565B02:2,1</string>
</dict>
Deleted com.apple.soundpref.plist with no replacement file

Updated to 10.6.5 and changed Audio MIDI setting, everything working.
Waiting and hoping??

Audio MIDI is in the application-utilities folders

i still get a 50% performance hit with the sound issue in my games (frame rate is half what it should be) even though I changed the MIDI settings. maybe i'll try deleting that file

Question: anyone have an educated opinion regarding the potential danger of electrical problems surging back into the CPU or video card as a result of this issue?

Same problem on a recent 27 display, received Oct 30. Used it with a new 2010 Air 11" for a week or so, no issues. Then connected it to my 2008 Mac Pro 2.8 Quad with a new ATI 5770 card purchased fro Apple in order to run this display. Exhibited the problem addressed in this thread for the first time today, on the Mac Pro. Unplug/replug worked. As some have suggested, my experience so far has been that the problem did not manifest with the Macbook Air 2010, but cropped up on day 2 with the Mac Pro 2008/5770.

I'm not immediately concerned about the audio issue per se as I have an audio setup that bypasses the display, other than that it may cause other headaches as a by product. My opportunity to return for refund lasts 2 more days. That would be prudent except that I will lose the 3 year AppleCare protection that comes with purchase of the Air I bought with it- doh! Subsequent re purchase would then cost $100 to add AppleCare and I wouldn't buy one of these things without 3 years of coverage. So I am inclined to keep it and wait for Apple's resolution UNLESS and it's a big unless, there is a chance that this issue propagates an evil signal back through the video card with the potential to wreak other havoc.

My guess is no, but I cannot be 100% sure. My guess is also that people have been unplugging and plugging back in their monitors for a while now and I haven't heard about anybody having any power issues like that. This is just a guess though.

I also have sound through the dat after following the instructions of deleting plists. So far, so good on sound, but I do notice delays still with volume buttons, but also when deleting files and undoing sounds where there is a delay when completing those actions as well. Even if sound works, I'll consider it a temp fix until a solution for the delay is released by Apple. I hope something is released to fix this issue, especially for those that do not want to delete plist files in their systems.

Guys, pyramidal explained how to reproduce the problem:

* mute the sound
* put the computer or display to sleep (for me ctrl-shift-eject suspends the display)
* wakeup and notice that there is no sound.

Now I wonder if any of you who deleted the .plists in /Library or has a replacement display can still reproduce the problem?

BTW, my guess is that its a nasty software / driver problem and cant be fixed other than by a hotfix from apple....

And just to remind you of another solution than unplugging your display (though this only works for newer machines that have audio over display port):


* Go to Sound Preference Pane (or alt-click the sound icon in the menu bar)
* Change the output from DisplayPort to USB (or vice versa)
* Press Volume up / down to produce a sound.
* Change the output back to DisplayPort.

Ok thats what I had done,

1. Change the Midi setting to 48K and 24 bits

2. Reinstall the OS 10.6.5 Combo

3. Trash the .plist as suggested

So far, I do not have the same problem even doing the following :-

* mute the sound
* put the computer or display to sleep (for me ctrl-shift-eject suspends the display)
* wakeup

Fingers crossed.

SHAME!!!!!
Arrived today!! my new 27" and SOUND DOES NOT WORK!!!!!!!!!! a monitor that cost a fortune!!!!!!
THIS MY LAST APPLE product I PROMISE!... and on Monday i will send it back to you "APPLY" guys!
****! ****!
I CAN NOT spend a days for a monitor issues !!!!!!!!!!!

Do you want my recent stories with apple products? JUST ASK! It's a long TRAGIC story!
thanks.

IM FURIOUS!!!!!

I rang Apple Support today (UK & Ireland). They were not aware of the issue (or weren't telling me if they were). I had temporarily resolved it by disconnecting the displayport and usb connections for 15 seconds but wanted to call them anyway to make sure I had a case ID for future reference.

He got me to reset the PRAM but since everything was already working I have no idea if it will have any effect. Sound is still working since yesterday when I disconnected the monitor from my MacPro.

He said to call back if it happened again and they "will organise a repair" - how can they offer a repair on a monitor that is one week old? I want a replacement not a repair. Seriously considering buying AppleCare to get additional 2yrs of cover.

I bought a new 27" monitor last week and I also have the same issue of loss of the audio in the display speakers. I also had dirt under the screen and one dead pixel so the Apple Store exchanged it for me but the second unit also has the audio problem. I've arranged to return mine for a refund. I'm not going to have a brand new monitor disassembled & repaired for a problem that came with the monitor. Whether it's a software problem or display problem, when the issue is solved I'll buy another one.

I'm beginning to think a return/refund might be the best option also. The only problem is I dont have a spare and I dont want to buy another monitor only to find the 27" LED issue is resolved in a month 😟 What to do?

Please Apple, do something about this! I always have to restart now and then to enjoy sound via the Cinema Screen! It's really annoying! After a restart it works for a while, then the same problem again!