En vísperas de una travesía, al actualizar los mapas de Mapear se me colgó mal el Montana y no había forma de revivirlo, pese a una frenética búsqueda de soluciones en Internet. Consulté a GARMIN Internacional para ver como ejecutar la garantía y me mandaron una receta mágica, que la comparto por si alguno le pasa:

Dear Sergio Zerega,

Thank you for contacting Garmin International. I would be happy to help you with this.

It sounds like you have a corrupted map file on your device.

First please remove any SD cards you have in your Montana 650 and try it

If the above steps don't fix your issue then we will need to remove the maps from the device.

To do that, please do the following:

1. Turn off your unit.
2. Press and hold the power button, and plug the unit into the computer. (I would recommend you hold the power button with your off hand {IE a right handed person should hold it with their left}).
3. Open your MyComputer
4. Open the Garmin Drive
5. Open the Garmin Folder

Here you will find all the map files, they will be .IMG files.

You should have the following files:
gmapbmap.img = Basemap
gmaptz.img = Time Zone map

Any other IMG files weren't installed via Garmin. Please Cut and Paste
them to your desktop and try to have your Montana load up again.

If this fixes the issue, please load the maps from MapInstall to your
device again.

Please let me know if you have any further questions. Thank you and have
a great day!

With Best Regards,

Heath H
Product Support Specialist
Garmin International
913-440-8280 (fax) Att: Heath H, Associate #6191