You might want to check the Audio settings in Audio/Video option. Go through the setup and ensure that you’ve enabled optical output and then selected ONLY those audio formats that you’re sure your receiver supports. For instance, I’ll guess that it doesn’t support AAC (as I learned to be the case on one of my Yamaha’s).
After all that, and you still don’t get audio, you might have a hardware problem somewhere either in the WD itself, optical cable, or receiver. Not saying that you haven’t troubleshot those, but if not, you might plan on doing so.
Good luck.
