While preparing for a road-trip tomorrow, I decided to play with the navigation system and plot my course, since I never use it...it's usually driven locally by my wife....shoulda left it as is, but I only wanted to make life better! A Google/ YouTube search got me to crack into the menu and only AFTER I had selected the software update (seemed intuitive if I wanted newer info) on the perfectly-working screen, that it went blank, and THEN was I later warned by the attending guru NOT to do that....I take full responsibility for my temporary lack of good sense. My wife does not know this...yet. She thought I was a genius after fixing the TPMS error that plaqued us for months while I was waiting to put on new tires and trouble-shoot the whole system then (had already tried the usual recommendations I found on this wonderful site; a TPMS module replacement was required but only cost $30 on eBay). You've gotta like challenges if you own a jag, more so if you own two. I just can't understand why Jag would link critical systems controls like cabin temp/defrost/defogger/fan, etc to a screen that is non-essential like navigation. The screen is black and I can't tell that I'm making any changes to any of those controls when I toggle the fan, defrost, etc. I've tried the phone/menu button recommendation and removing the neg. battery cable rec. and still no fix. The defrost fan works but I am unable to change it, it seems to be on front defogger only. A plus is the CD player and radio work but unable to "see" the buttons to change the radio stations except for the mechanical scan button. I have the original map DVD, but nothing else. Although a member for a while, I've never had to actually post, I've always found good answers from previous posts. Any further suggestions on a fix would be greatly appreciated. Maybe a mistake, but I still plan on the road-trip tomorrow. Thanks in advance if I miss your replies for a day or two.