I really appreciate the ideas and if I were you, I would suggest the same things. Unfortunately, I've tried and eliminated all these things. The bar has a remote, and input settings, which seem to do nothing. I've tried toggling them and nothing happens, many times. And I know it is not the TV, because I was already using an optical cable into a tuner that ran my other speakers and it worked fine. The TV has good settings for optical output only or both optical output and TV speakers. I've also tried RCA cables, which is a setting option on the TV. I've toggled the mute button countless times, fearing the same thing. The lights all work. If it is plugged into Optical the soundbar light is solid green. The SW has a blue light. If I toggle the input switch the green light goes blue, for bluetooth, but bluetooth doesn't work either.
It's all why I am left scratching my head.