Some modern devices only stay in preboot for a matter of seconds. There is a way to power on with cure firmware already loaded to Updater.exe, once the flash is initiated the device won't exit preboot until flashing has finished, we'll cover that method below. Go to [Only registered and activated users can see links. ] to read how to create a Cure firmware and understand it's purpose. In brief, it's to re-enable Mass Storage Mode to access internal files, not to boot the device (i.e. it'll still be stuck on the logo splash screen) but importantly recognized by a PC in MSM as well as preboot mode with Cure fw loaded. Note that there are two ways to do a cure, the first and most reliable is to make the cure fw from the device's actual native firmware, the second newer and less reliable way is to use a universal RGN file known as QuickCure3. You'll find a link to a compressed RAR file containing QuickCure3.rgn at the base of the initial post of the Cure3 thread. Extract QuickCure3.rar to find the RGN file and rename it from QuickCure3.rgn to 113201000390.rgn (that exact naming is important to ensure safe flashing). Get Updater.exe from here: [Only registered and activated users can see links. ] then follow this:
  • Load the RGN file to Updater.exe and leave it's GUI open and visible on your computer's screen, ensure to select the Radio Button next to 'USB Device'.
  • Ensure the device is fully OFF. Hold the power button down for between 10 and 30 seconds until the screen goes completely blank.
  • Plug a 'known-good' USB cable directly into a REAR USB2 port of a desktop PC or a USB2 port of a laptop (no hubs, front desktop ports or USB3 ports).
  • Hold the top LH corner of the device screen firmly (i use left thumb) while plugging in the cable to the nuvi's USB socket, watch the window adjacent to 'USB Device' for the device details to appear.
  • IMMEDIATELY you see the window populated either hit the enter key on your computer or click the OK button on the GUI.
  • Keep holding the device screen firmly until the flash finishes or at least until to you see 'Loader' or 'Software Loading' appear on the device screen.
  • When the flash finishes, hopefully the device will appear in Windows Explorer and you can remove any file which you suspect of being faulty or reformat the internal memory as suggested in the Cure3 thread initial post.


If quickcure dosn't work to re-enable MSM, then download the NA fw, you can get it here:
Code:
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However, it you have a complete backup of the nuvi's existing internal folders and files and locate the file named GarminDevice.xml in the .System folder, there's a way to 'trick' Garmin's server into giving you the current EU firmware version. Let me know if you have that file available before preceding further as it'll make the whole process of fixing your nuvi 1690 much simpler.

Post again to advise if Quickcure did or didn't work and also if you have the GarminDevice.xml file in a backup or on the device if you've managed to regain Mass Storage Mode with Quickcure. We can then go further.