Hey guys! just recently joined this site heard it was very useful! i have a huge problem right now, my friend was playing around with the navigation screen (i don't have the cd in the back so the navigation does not work) and he entered some hidden diagnostics screen by holding down the phone and menu buttons at the same time! i believe he accidentally clicked some update or restore of some sort, it said failed and the screen wasn't going away, i tried turning off my car and even taking the battery out but now my screen doesn't even work! please this is very urgent if you guys know what to do let me know thanks a lot!!