I recently got rear ended and my nav disc box got destroyed. This in turn caused my nav screen to go blank. The radio and everything still works and the backlight on the nav screen is still on just blank. My question is if I go purchase a used box from a junkyard and plug it in, will it work? Do I HAVE to have the disc if I don't use the map part of the screen? Or will I have to send the box to Alpine in CA and have them reprogram it? Please tell me in detail what I need to do. Thank you guys!