No audio from surround sound through optical connection to Sony Blu-ray player

by PKMLL
(Australia)

The DVD player in our LG surround sound stopped working properly so we bought a Sony Blu-ray player. We used an optical cable to play DVD through the Sony Blu-ray but still get surround sound through the LG.

We set this up and it worked fine, however it has now stopped working. We have checked all connections. The LG can play DVD's a bit so we were able to check the speakers all still work.

The Sony B-R works of course with sound through TV, but we cannot get any sound to come from the Sony through the surround sound. Are we missing something? Not sure what we can change regarding the settings, but we did have it working at one stage.