I sent my n2 in for a cable upgrade because my screen went out.SO I called to check the status of my repair and the tell me there's more problems other than the flex cable.everything was working fine before i sent the unit in for repair.So i told them not touch anything else just fix the cable and send it back. i received my deck back and now it plays CD's, but when i put in the navi disc to set up everything it says reading disc, upgrading, then it says then upgrade failed. why is this? what should i do the Navi was working before the screen went out.