DEMO appears on the display panel and the remote control buttons don't work
IMPORTANT: This article applies only to specific products and/or operating systems. Check Applicable Products and Categories for details.
If this occurs, the DEMO mode is on. While the DEMO mode is on, you can't turn off your device using the Power button or display the menu when you press the HOME button.
To cancel the DEMO mode, press and hold the INPUT and Power buttons simultaneously on the front panel of your device for more than five seconds.
Alternatively, you can also disable DEMO mode by simultaneously pressing the Power and VOL + buttons on the unit for five seconds. If you perform this method, it is recommended doing so with the sound off. If you are using a model other than what is listed in the Applicable Products and Categories section of this article, refer to The volume of the Soundbar suddenly turns up, or the Soundbar does not turn off even when pressing the power button. (Demo mode) article.