Thread: Nüvi 3790

This is a situation that occurs when Windows detects errors in the file structure and tries to recover them
I would definitely advise you to backup the entire content, format the memory completely and then restore the necessary files. Preferably install fresh system via Garmin tool

In principle I will not format the drive. It seems to be without any defects, or at least, Windows has analyzed it and everything is fine.

I have read about it and I have not found any step by step that speaks clearly about how to format the drive.
I have doubts:
-If the nüvi drive is formatted, once formatted as FAT32:
-Does the PC detect the formatted drive?

-You tell me that it is better that I install a new system from Garmin Tool:
- Do you mean Garmin Express?

- For the installation of a new system:
- Did I have to copy the backup files to the formatted drive first, or does the drive have to be empty?


Thanks Boki

Yes it's as Boki said, the FOUND folder is not to do with the device itself - other that the actual file corruption source was caused initially by the device malfunctioning. I think at some point you've run CHKDSK, probably when prompted by Windows on connection of the device to PC. It's quite safe to delete that folder and the hidden "suspension/trash" folder with the video files as you've done to gain space.

I would hesitate to again re-format the file system however unless there are more corrupt files and folders later that refuse to be deleted. That may be ongoing in fact. Keep in mind that presently it's the nonrepairable corruption in region 41 that is at the root of all this device's problems. That has been shown to be uncorrectable by software means, neither clearing of delete-able data nor erase of the entire region works.

Only region 48 (the visible file system) is accessible by Windows built-in tools or by any other 3rd party software like MiniTool or EaseUS partition managers. The closest you can get to a conventional re-formatting of any region other than 48 is to erase it via an SD text command - do that to the wrong region and it might never boot again. For example, running "ergn,5" in Update.txt, if successful, would erase the bootloader which is roughly the equivalent of a PC's BIOS/UEFI firmware.

Note that if you do have to reformat the file system by absolute necessity, don't use anything other than [Only registered and activated users can see links. ] on a PC. A Mac will mess it up almost certainly and Windows (whether via Disk Management or any other 3rd party software) can be quite hit and miss. There are as many ways to format in FAT as skin a cat .... ... some work, some don't but for Garmin devices RMPrepUSB is totally reliable using the recommended settings.

EDIT: P.S. Sorry, forgot to say this: Re-flashing the firmware won't change anything in the File System, it'll only flash the firmware regions [aka the system software regions, 14 (0x0E) and 127 (0x7F)] and the ramloader in virtual region 12 (0x0C). Those regions are NOT your problem of course anyway. And yes Disk Management will detect an empty formatted drive. Windows File Explorer won't if Folder Options are set to not show empty drives:

Spoiler: click for image

[Only registered and activated users can see links. ]

Originally Posted by Neil

Yes it's as Boki said, the FOUND folder is not to do with the device itself - other that the actual file corruption source was caused initially by the device malfunctioning. I think at some point you've run CHKDSK, probably when prompted by Windows on connection of the device to PC.

At first, this is how I thought it could have happened, although it is also possible that so many connections and disconnections to PCs (Windows 7, 10) and MAC have also contributed to incorrect reading and generated corrupt files. Yes, I have carried out an analysis and correction of errors, although Windows has never found any errors.

Originally Posted by Neil

It's quite safe to delete that folder and the hidden "suspension/trash" folder with the video files as you've done to gain space.

That's what I thought, they are files that don't contribute anything and although there is still space on the disk, I preferred to delete them. It really bothers me to delete a video file and open the application and it continues watching it.

Originally Posted by Neil

I would hesitate to again re-format the file system however unless there are more corrupt files and folders later that refuse to be deleted. That may be ongoing in fact.

At the moment I am not going to format the unit, it is working normally, in principle I have not observed anything strange and I still think that the multiple connections and disconnections to the PC's and MAC have generated this situation.

Originally Posted by Neil

Keep in mind that presently it's the nonrepairable corruption in region 41 that is at the root of all this device's problems. That has been shown to be uncorrectable by software means, neither clearing of delete-able data nor erase of the entire region works.

That's right Neil, this is more than proven. Still, the device doesn't do strange things and works fast and well despite the drawbacks.

Originally Posted by Neil

For example, running "ergn,5" in Update.txt, if successful, would erase the bootloader which is roughly the equivalent of a PC's BIOS/UEFI firmware.

When I was executing commands from the SD card, to copy, delete or write region 41 and with all the information and help you gave me, I imagined that this region and the non-accessible ones acted in a similar or equal way to the BIOS of a PC.

Originally Posted by Neil

Note that if you do have to reformat the file system by absolute necessity, don't use anything other than [Only registered and activated users can see links. ] on a PC. A Mac will mess it up almost certainly and Windows (whether via Disk Management or any other 3rd party software) can be quite hit and miss. There are as many ways to format in FAT as skin a cat .... ... some work, some don't but for Garmin devices RMPrepUSB is totally reliable using the recommended settings.

Thank you very much Neil for your explanations. If I need to format the drive someday, I will use the software you indicate. I thought it could be formatted from Windows Disk Management.

Originally Posted by Neil

EDIT: P.S. Sorry, forgot to say this: Re-flashing the firmware won't change anything in the File System, it'll only flash the firmware regions [aka the system software regions, 14 (0x0E) and 127 (0x7F)] and the ramloader in virtual region 12 (0x0C). Those regions are NOT your problem of course anyway.

What you indicate with these words, but without much knowledge on my part, is what I have been learning throughout this process of recovering the nüvi. This is the reason why we have been able to transform my nüvi into 34xx, and we have not been able to reset it as 3790. We thus confirm that formatting the visible drive does not help or improve anything at this time.

Originally Posted by Neil

And yes Disk Management will detect an empty formatted drive. Windows File Explorer won't if Folder Options are set to not show empty drives:

Spoiler: click for image

[Only registered and activated users can see links. ]

Perfect Neil, thanks for your clarification. Not having any experience formatting this unit gives a lot of respect.

At this point I feel obliged to say that we have managed to reach the end of the journey. A journey in which many surprises have arisen, which we have been able to overcome.
The nüvi 34xx is fantastic, it works fast, it has a user interface that is light, fast, intuitive and much improved compared to that of the nüvi 3790. The nüvi 34xx has all kinds of applications, music, videos, audiobooks, in short, applications that they work perfectly. In terms of the speed of satellite reception, it is spectacular and in terms of precision as well. The only precaution that must be taken so that the precision is perfect and that the vehicle does not jump during the journey, is not to have the map enlarged to the maximum. The voice command search is amazing, it works like a charm. I was used to what the 2012 City Navigator with nüvi 3790 offered, nothing like what the nüvi 34xx offers with the City Navigator 2025.10 version.


In short, I AM VERY HAPPY to have spent all this time accompanied by people like you, Neil, people who go out of their way to help, offering their time in exchange for nothing.

Neil, you are a person who shows with your explanations that you are passionate and an expert on the subject, very good people, really, it has been a pleasure to meet you.

Thank you, thank you, Neil, Garman and Boki for all your attention.

Hugs.