I just bought a new (to me) vehicle with a kenwood excelon kdc-x790 installed in it. it doesnt have any manuals that come with it. For some reason the head unit is in "DEMO MODE". The words demo mode continually blink across the screen, also the screen constantly switches backgrong scenes. Its like something you would see at an electronics store where the head unit would be on display for the people to see. If anyone could help me get rid of "DEMO MODE" i would appreciate it. Thank you