I bought a used nuvi 255W from a friend. I do not have the serial number and someone has soldered a usb cable directly into the unit for CHARGING only - it works fine while in use or off. I would like to know if I am able to update the map (I believe it's the lower 48) However, I can not get my laptop to find the nuvi via the usb connection. Maybe I need a different cable - but if and when I get my laptop to acquire the nuvi - how do I update the map? I have already downloaded the Garmin web program - and it searches for the unit but fails to find it. Will I need to purchase a map update of are therfree ones available on the web? Like i said - I have no idea of whom, or when this unit was purchased and I do not have the serial #. Suggestions?
