Q: No sound from Thunderbolt display

MSM126 - have you tried booting then 'sleeping' MBA independently, then plugging in TB and waking the wafer thin chap? Worked for me whilst I kept up the routine but lately I forgot and, bless me, the bloody sound works fine now...

When I first got MBP + TB I received the advised TB software update which never would install - I never did ask if this was installed by anyone here successfully?

Designer,

Yes, I should have made that clear ... the work around resolved the problem for me; though like others here it was a temporary fix.  I spoke with AppleCare.  They took me few quite a few things, then did a quick and then extensive hardware test.  Apple is aware of the issue, but don't seem to have a fix on the cause or a resolution.

I have about 10 days left in my return window.  I'll just return both the display and the MBA, and switch back to my MBP (mid 2009) if I'm still seeing the issue this weekend.  Then I'll just wait to see what happens when the dust settles on the issue.

The soultions offered in this thread didnot help me, but I was able to go into

system preferences -> Sound -> Output -> USB Audio

Although I did just update the Thunderbolt drviers today, this is something that should be automatic when plugging in a MBA to the display.

I found this out on accident. Hold ALT/OPTION and left click on the volume....thing.... on the top right of your screen, if its not there you can put it there in system prefrences>sound and it says show volume in status bar with a check box next to it. Then you will get input and output options to appear. If this doesnt work immediately sometimes if you try again a few times it will pop up.

     Ask if you have any questions

edit** under output in the pop up thing, internal speakers are the things you hear music from when no headphones are plugged in........ and whatever it says below that is most likely your external displays speakers.

I had a wishful thought that perhaps Apple would secretly address the problem in their new OS X Mountain Lion.
After rushing to put the new cat on the Air (2011), I realised that this cougar, like it's cousin Lion, cannot roar through the display most of the time.

To all those who share the same deam, Mountain Lion doesn't have the solution, yet...Sigh

You saved my day

your welcome good sir. apple made the ways to do it, they just were hiding it

This was the answer, thanks.  Wish I could figure out how to mark this for Solved My Question points...

This isn't really helpful, since the input/output options are already easily found within System Preferences > Sound.

The issue is that my Thunderbolt display (Display Audio) isn't listed as an output option at times.

Since the Display Audio option is shown as "USB", I have to believe that an earlier poster was correct in that it is a USB issue.

Screenshots before/after a reboot:

Hi IP,

I looked in that part 2 and thought there must be the problem until i did the "Hold ALT/OPTION and left click on the volume....thing.... on the top right of your screen" and see more/other options then showed in the system Preferences sound. I am now not behind my Thunderbolt but will upload the screenshot tomorrow if this would help.

I'm not sure what you're trying to say...

The option+click doesn't really accomplish anything that isn't easily done via the sound pane in preferences. But that's completely irrelevant to the problem. It doesn't "fix" anything. Being able to look at my input/output devices in that manner isn't helpful if the device (the Thunderbolt display) isn't in that list. After a reboot, it was.

Well it solved my problem with the sound on the thunderbolt display. As you can see on the screenshot the 2 things show complete different possible setups where i thought also that the preference would show all.

Is the system sound through the Thunderbolt display ? or there is no sound at all. In my case the system sound was through the Thunderbolt but any music or movie sound with through the Mac speakers.

This happend after I updated to Mountain Lion by the way. It just changed the confiruration.

The thunderbolt display wasn't being listed as an output device at all, regardless of where I looked for it.

Correct, it's clearly a USB issue.