TV is a UE65KU6000
I have connected with optical lead from TV to soundbar (with no hdmi from TV to bar)
Selected audio out/optical from the TV sound menu
Then grouped the speakers in surround mode through the app and not changed the tv
Then used the sound bar control to select D.IN as the source
Once I get home from work I will try testing with optical out from my PC to see what's what.
In Netflix, search "test", click on the Netflix test pattern set and that has a sound test I beleive.