I just purchased a new Yamaha soundbar, YAS - 108, and cant get my Sharp LC-42D64U to talk to it. There is no ARC HDMI input so the Yamaha manual says to connect both an HDMI cable from the output on the soundbar to an HDMI input on the TV as well as connecting the Digital Audio cable. I've tried many of the open HDMI ports on the tv to no avail. I've checked the TV manual to see if there is a setting that is blocking my tv from communicating with the soundbar but I don't see anything. Not sure what to do or try next, going with an analog connection is the last resort.
Forget the HDMI since the TV doesn't support ARC.
Connect the optical audio output of the TV to the soundbar. Turn the optical output on in the TV menu. You may also have to turn the TV speakers off to get it working.