Connected a Cinema Display to MacBook Pro, recognizes sound output device but no sound I connected my new Cinema Display to my MacBook Pro and the audio output device shows "LED Cinema Display" in Sound Preferences, and the volume controls work, but no sound is output.

I tried unplugging and plugging back in the USB cable.

Is my device incompatible, or is something wrong?
(I solved my own problem right as I was about to post here.)

The Mini DisplayPort must be plugged in before the USB cable.  Unplug both, plug them in in the correct order, and it should recognize the sound.

Unplugging only the USB cable will not work.