Hi moelou, welcome to GPS Power.
- How is the SD card formatted? It should be FAT32.
- How exactly did you reset the device?
- Normally the "No Data Available" message appears when trying to find an address while no detailed map is available. However, you say it does show the new map on the card, so I am a little puzzled. What exactly do you mean by "it"? The nüvi or your computer?
- The map file should be named gmapsupp.img and placed on the SD card inside a root folder named Garmin.
- To make sure you use the correct file extension, verify that the option "Hide extensions for known file types" is not selected in the Folder Options menu on your computer.
- When you view the map, do you see details when you zoom in sufficiently?
- If all of the above have been verified and you still get the error message, try searching for a destination other than by address, e.g. by:
> Touching a location on the map
> POI - Point of Interest
> Street Intersection
> Latitude and Longitude (Coordinates)
> Your own saved waypoints
Does any of that work?