I read that manual but don't see if you tried the Trim level.
We have a Boston acoustics sound bar on our Samsung tv. The sound bar turns off every few minutes. It does not do this with other tv's.
The tv is UN55C7000wfx2a. And the sound bar is bostontvee26. When we bought the tv two years ago we bought a Samsung sound bar and had a similar problem. We returned the sound bar thinking that was the problem. Now that we are having a problem with a second sound bar, it seems the tv must be the problem. Hope the model number is correct. I am trying to read it off the back. It is a two year old, 55 inch 3d.