Audio problem with yamaha receiver

[meg6234]

My Yamaha receiver has been excellent except for the maybe 4 or 5 times over the last four years since I
bought it, when all of a sudden there is no sound. I'm trying to remember if there is no sound when I turn on the TV etc. or if it stops mid-viewing. I THINK perhaps it has happened both ways and when in mid-viewing, I wondered if I had pushed something on the remote that i shouldn't have.

I stopped at the store where I bought it today and was given no help whatsoever.
I will be grateful for any suggestions!!!

 

[anwaypasible]

maybe the radio picked up a signal from something.
could have been a prank (on purpose or accident)

what happens when the audio stops?
how does the audio come back on?
no error message obviously.. does the light change or flicker?