NO SOUND!!

I have been using my 2nd gen apple tv for awhile now. Worked just fine. Then out of the blue, the sound stopped working. I have tried all of the recommendation s specified by apple, ie:

http://support.apple.com/kb/TS2090

with no luck. No problems with the sound on my AV receiver. It works on all of the other settings. Just apple tv does not work whereas it used to work just fine a week ago. I have unplugged everything, i have reset the apple tv. I have changed the audio settings. Nothing seems to bring the volume back. Any thoughts?