I don't know if this works with all models, but it worked with mine. I unplugged the unit, plugged it back up, turned it on, and right after it rebooted, I unplugged the optical input, waited a couple of seconds, and plugged the optical input back in. Display then showed 'OPT'. That was the only thing I found that would get it out of the dreaded 'DEMO' mode. Hope this helps with your model too.