UN40J6200, cable set top with hdmi, digital optical out to Vizio sound bar.
In cable mode sound bar works. If using Netflix,Hulu, or Amazon the sound bar is silent.
Here is the fix. In normal TV mode the audio format is PCM. All other options Dolby Digital,DTS,DTS Neo are grayed out on the sound menu. When you switch to Netflix the sound bar won't play using PCM. So while playing an app like Netflix which uses Dolby digital, go into the tv menu,sound,additional settings. You will now see that Dolby digital is now available in the menu. Select it. SOUND BAR NOW WORKS. The speaker settings should already be on external speakers. I believe this is a Samsung problem that could be easily fixed with a firmware update.

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