On some TV's the Surround Sound setting causes a muting of the sound. If you do not have or are not utilizing a surround sound system then the following are generally the best options
Sound Effect - Standard Simulated stereo setting - On Duel Sound - Stereo Auto Volume - Off Speaker - TV Speaker Set the Treble, Bass and Balance to their mid points
Leave the Audio settings on the V6 box on Dolby Digital to PCM
Going back to basics and getting the settings maximized for a given TV using its internal speakers, has the advantage of knowing that you can then add a sound bar and make a couple of changes and easily hear the differences.