Thread: Garmin dezl 760 - bootloop

It's "Soft-bricked". When such a device tries to boot it attempts to load essential files and if unable to do so completely because one or more files (IMG, GPI, VPM etc.) is corrupt it will stick on the splash screen or spontaneously attempt to reboot. Seeing it shows 'Loading Maps' then reboots i'd suspect a recently loaded map IMG file to be the problem, particularly if you've recently tried to update the map entitlement with Garmin Express or have tried to load another map or ancillary file(s) manually. If it's the latter and on a microSD then simply removing the card allows normal booting, but to access the internal memory you need Mass Storage Mode of course.

To re-enable Mass Storage Mode so you can remove any potential faulty files from the internal memory or re-format it, you must load "Cure firmware" which bypasses loading those files on boot. That fw must be loaded to it in preboot mode, aka Garmin Mode, which your device has. That's the state it's in when you can see it in device manager, showing as "Garmin USB Device" under "GARMIN Devices". On dezl 760 you should also be able to gain preboot mode by holding the top left corner of the screen while powering on. That way to do it (in a healthy device) eventually defaults to the screen calibration whereas the lower right will ask you to select the Locale, clearing user data and defaulting selection to the original market set for the device on initial programming from the factory.

Go to the following thread to get a small program to easily make cure fw and either post there or again here if you have any questions after reading the thread, particularly if you don't understand anything in the the initial post. [Only registered and activated users can see links. ]

GarminExpress doesn't detect devices in preboot/Garmin mode. It's limited to use in Mass Storage Mode or Media Transport Protocol ONLY and cannot access devices in preboot, like for example Updater.exe which is used to load firmware only as an RGN file in preboot.

Certainly immediately AFTER you successfully loaded the fw made with Cure3, the device would have re-booted with Mass Storage Mode and Media Transport Protocol re-enabled. The MSM/MTP should not have disappeared again after you loaded the original fw. Try completely closing GE (check that it's not running in the background) and rebooting the PC, then if GE still doesn't see the device post again with more details.