I have a new Vizio soundbar sb3851 connected, via optical audio which is the only way to connect them, to Samsung HLT6187sx, but I am not getting any sound
You may need to turn on the optical output, turn off the TV speakers, and change the audio output type in the TV audio menu. Make sure you select the optical input on the soundbar.
You may need to turn on the optical output, turn off the TV speakers, and change the audio output type in the TV audio menu. Make sure you select the optical input on the soundbar.