Tried something similar with my KDL40HX723. I put it through my hifi using the red and white phono connectors, but I couldn't get any sound out either. Hifi doesn't have optical, so that isn't an option. Had a fiddle with all the sound settings I could find but didn't make any difference. Did you ever find a way round it or did you just start using optical?
Message was edited by: sony-cat