Hello, first time poster here.

I am looking at a 2004 gx470 i am considering buying. It is in perfect condition except the navigation screen is just static. The climate control and radio menus work fine, but anything to do with navigation is just static. The guy i am purchasing it from says he called lexus and they wanted to have him send it in and have it rebuilt for $600. I am fine with doing that or purchasing a used unit on ebay but i just want to make sure the problem is actually in the nav unit, not in the disk reader or antenna or something.

Anyone have any clues on what could cause that?