Yesterday, my 1490 froze while navigating. Tried to reboot by pressing on/off button for a couple of seconds, unit partially booted and froze at the garmin logo screen. Back home, I tried to connect it to my computer, nuvi did not show up as a removable drive anymore.
Flashed cure firmware with GarminCure3 tool, unit went into mass storage mode ok. Found a number of corrupted files. Deleted corrupted files, made backup of all other files, reformatted nuvi with FAT32 and restored content.
Flashed original firmware with GarminCure3 tool - all problems gone.
Thanks very much, kunix!