For such an expensive device it's a real shame where the only viable option left is to break it down for parts. The hardware repair option is onerous however.

Are you absolutely sure it cannot enter preboot? It's tricky to do with a damaged unit but persistence will sometimes pay off. Units that restart every few seconds like yours are notoriously difficult, timing and luck come into it. I recently spent literally weeks trying off and on to access and maintain preboot in a bricked SP2720. Every morning i'd spend a few minutes then suddenly one day i was able to flash it - it would have totaled dozens if not over a hundred attempts then bingo! It worked!

This test can hardly cause any further problems if you want to try. It will at least show if preboot is possible even if only for a brief moment. The thing is if the boot looping can be interrupted by a flash started in preboot then there is a chance to fix it. In the RAR pack is the 2797 ldr.bin [boot.bin] made into an RGN file so if you do manage to flash it the unit might then start normally, but doing the actual flash is not so much the purpose at present. If you can initiate the flash that will be great, but really this is to see if preboot can be reached at all for the time being:

  • Extract this RAR file to somewhere convenient on your PC and then drag boot.rgn onto Updater.exe to open it's GUI. Enable the radio button to the left of 'USB Device' and leave the GUI visible with your mouse cursor positioned over 'OK'.
    Spoiler:
    [Only registered and activated users can see links. ]
  • Plug a microUSB cable into a rear port of your PC, but not into the 2797 just yet.
  • Make sure the 2797 is fully OFF.
  • Holding the unit in your left hand, press your thumb quite firmly in the left-hand top corner of its screen and plug the usb cable into it while carefully watching the GUI to see if 'nuvi xxxx (Unit iD xxxxx' appears in the window to the right of 'USB Device' and/or 'System' appears on the device screen. You may also hear the Windows device connection sound.
  • If you see/hear any of the above activity immediately click 'OK' or hit Enter on PC keyboard and keep holding the screen with firm steady pressure until the flash finishes [Updater.exe message reporting success].
  • If you do manage to flash the boot.rgn, and the unit 'wakes up' it will probably be stuck with 'Loader' showing on the screen. That's only because it's waiting for further software other than just the boot.bin so just force it off by holding the power button, then see if it will start normally.


BTW, in your post above you have the folder name '1715'. 2797's HWID is 1517. It wouldn't make any difference even if the SD card is being seen i believe, because neither folder name would be recognised by the unit which has had 3597's HWID of 1603 written to it when you tried to enable TracBack.