I tried to update my XXL 540 yesterday. Apparently during the process, I had to leave my computer for a while. When I came back. there was an error message to the effect it did not complete the process. When I turned the XXL 540 back on, it said No Maps Found. So, I tried the update process again and made sure I sat through the entire process. It finally completed. But, when I tried to turn it on, the screen briefly came up and then died. I tried the reset feature, after charging for 3 hours and when I tried to turn it on, I got the same results as before. After holding the power on button down for 15 or so seconds, the screen would come on with the TomTom Logo, play a little jingle, brink back the TomTom logo for several seconds, then nothing. It appears that I killed the unit. Have submitted a request to TomTom asking about repair warranty, as I purchased it last September. Haven't heard back yet. Any idea's?