Digital audio does not work

Hi there! Can anyone help me?

I have connected the WD TV Mini with my home cinema set via the optical cable. Playing VOB files and selecting the digital channel on my home cinema set does not produce any sound. Sound comes via TV only. 

Any suggestions? 

I have the EXACT same problem. I had it running when I first hooked up the player to my home theatre system but i moved and now cannot figure out for the life of me why it won’t work now…should be simple right?.. A goes into B