2004 Accord EX/Sat/Nav/CD Changer - No sound from any source - display is fine

Looking for help to begin diagnosing or maybe this is a known problem.
My Accord is 2.5 years old, 55k miles and just yesterday the audio has
failed.

I don't even know where the fuses are on this thing; but not sure
that's my problem. All audio sources appear to work fine, displays are
correct and respond to input, navigation, everything appears to work
correctly but I have absolutely no sound. A very subtle pop when I
turn on the audio system; not sure if this tells me my power amp is OK
or needs attention but that's it, nothing else.

I thought about checking the fuse to the power amp but don't know
where it is. Not sure where the fuse or the amp is.. and not sure what
other problems it could be. Obviously not the fuse to the radio/cd/nav
unit; display and tuner appears to work correctly. Very surprised I
don't hear any crackling, no small signal, no sub, nothing.

I have not touched anything; not attempting to wire up my ipod,
nothing like that. Audio simply has failed.

Any ideas?

thx,
Jeff-