We should now load cure firmware to region 14 to re-enable Mass Storage Mode and try to finish the job. If any part of the following doesn't work then we could be dealing with some kind of physical damage so cross your fingers. You'll need to use a clean empty microSD for this kit, if you use the same card as before make sure to keep a copy of it's contents before cleaning. Again, generally just follow Post #384 for the method. Look behind the spoiler for the flash kit and further info:
Spoiler: Click
[Only registered and activated users can see links. ]

  • Once the flash finishes the device should boot to the start-up screen screen showing only the Garmin logo with no text below it (it may then either go blank or just stick on the logo screen)
  • Don't try to turn it off or re-start it
  • Connect it to the PC and you should be able to browse the file system
  • Delete the entire contents of the Map folder
  • In the .System folder delete gmapprom.img and any associated GMA files and also UNL files if present
  • There should be no GMA or UNL files left in either Map or .System folders and the only IMG files left in the latter are to be gmapbmap.img and gmaptz.img
  • Don't remove anything else from .System for now except as above, i.e. the detail map gmapprom.img and all files with .gma and .unl extensions, all the other files and subfolders can stay there
  • Don't disconnect from PC yet
  • Open GarminExpress and select the option to update the detail map and wait patiently for it to finish, do not disturb it or let the computer sleep or turn it off - this is crutial!
  • When GE has reported the update is done, safely disconnect the device from the PC (Note that the device still won't completely boot yet).

Finally, you'll then need to flash the original firmware as an RGN file in preboot. Look behind the spoiler for further guidance and flash files:
Spoiler: Click
  • Extract this ZIP file somewhere convenient - your PC's desktop will do: [Only registered and activated users can see links. ]
  • Drag 175801000880.rgn on to Updater.exe to open its GUI
  • Select the radio button next to "USB Device" on the GUI and leave it open and visible with the mouse cursor positioned ready over its "OK" button
  • Attach a 'known-good' USB cable to a USB2 port of your PC (use a rear port if possible, no hubs or USB3 ports)
  • Ensure the nuvi is fully OFF, not just in standby - force it off it necessary
  • Hold the top left corner of the nuvi firmly (i use my left thumb with my fingers behind to secure it)
  • Plug the USB cable into the nuvi which will power it on, System or Loader may appear on the screen but keep watching Updater's GUI for the device's details to appear in the window to the right of "USB Device"
  • Immediately you see the window populated click OK on the GUI or just hit the Enter key on your keyboard
  • Keep holding the screen firmly until the flash finishes or at least until "Software Loading" shows on the nuvi's screen.

If all has gone to plan the nuvi should now boot up and function normally.