this worked perfectly to fix my bricked Garmin Nuvi 1490T. I just needed to find the firmware *.gcd for the nuvi (which is still available out on the net, but hidden on Garmin website), and the various other tools.

Firmware -- nuvi13xxand14xxseries_GCDFile__620.gcd

Applications --

Garmin Web updater
Garmin Express
GarminCure3.exe
RMPrepUSB
Updater.exe

It all just worked when I did the exact instruction on the first message of this thread. This needs to be passed along to more folks, as am sure a lot of Garmin GPS are being tossed in the trash.