Thanks for all the replies. The Garmin was purchased brand new from a major chain store similar to Wallmart in the US. The device is also registered, and the previous 2015.2 was updated with Garmin Express the last time. Neil, the serial number is not displayed at all anywhere in Garmin Express. If you communicate with the device using Mapsource, it does display the serial number, and everything works at it should. I can update his Nuvi with the latest 2015.3 map with Mapinstall, but he prefers to do it the "official" way seeing that he does have lifetime maps with the unit.