Please Help – my 3790lmt loss 3d building, terrain, Bluetooth & Speech command after map update

Looks nasty, but it does look like you did something you shouldn't have. I've not known any 3790 owners in here having your kind of a problem. Updater crashes, we just do it again. It actually looks like you wiped something out, not done by the updater. I see you installed red light Poi's, you did not get those files from here. You of course do not have a back-up of your unit? By any chance did you copy files from your 765 onto your 3790?

I have the same problem with my 3760T (which was on MapUpdater a couple of years ago, by the way). The map update failed. Once I redownloaded and installed it, my features were gone (Bluetooth mainly). Anyway, it now only recognizes the unit as a 37xx same as yours. I still have not done a factory reset on it though. I didn't have a backup either.

I purchased my 765T 1-2 year before my 3790lmt. The same custom POI were installed into BOTH of these units in the same week I purchased them respectively. They were both installed with the Garmin POI Loader -- importing 3 types of tiles (csv, .bmp and mp3) into both units.

My 765T can display both POI icons and speak the alerts. For the 3790lmt, it could only sound a bell; no icon or voice alert however. I just thought that it is the way these 3790 was designed... But I am very certain that right after the POI install, the 3790 has all the features such as bluetooth, voice command, 3D, terrain, etc because I did play with all the features of this 3790 extensively before I decided not to use many of them including both bluetooth and voice command because - VC was error prompt, cannot be trained; and I just do not want to pair my phone to the 3790 that interrupt the GPS driving functions (& other more reasons). For sure, the GPS files did not get corrupted by the POI's until later map updates became available a few months later after I purchase the 3790.

There were nothing else I installed into the unit. The files, however, could be corrupted by hot unplugging the 3790 from my PC (I did not know that I must "eject" the unit after update - as I was told by a Garmin rep).

No, I have backup my 3790. But my backup offer no help because as soon as I put the backup file to the unit, the garmindevice.xlm file got rewritten again by the unit.

No, I am only a "once in a while" user of these devices (retired). I did not use any other thing other than Garmin's software or utilities to upload or update files/maps into the unit.

This is the first time I ever join any GPS forum and ask for help.

I had no problem to all my other Garmin because none of them have lifetime map update. And they did not fail. 3790lmt is the only Garmin unit I have with map update and have this problem.
Thanks.

Try downgrading the firmware to an older version to have the xml file rewritten. To downgrade, find the GCD file on the Internet and copy it to the Garmin folder on the GPS. Disconnect the GPS from the computer. It should prompt you to update the firmware.

If that doesn't work, the GarminCure 3 software should be able to fix the corruption.

I had issues after upgrading my maps last fall. Garmin no longer supports/sells their CityXplorer maps. Once I uninstalled or "unchecked" all the CityXplorer maps in my nuvi 3790LMT, all my problems went away.

Tried that. My current version is 37xx 5.0 Downloaded 2 older gcd's, renamed to gupdate.gcd. Place one at a time to the garmin folder and test. But it will not load the gcd at all and went directly to load map instead. Tried the second gcd, nothing.
I think doing the above will work for most older Garmins according to what I read in other links. Could you tell me the detail steps on how to roll back on 3790? Did I do something wrong? Thanks.

I do not have other map or anything installed in mine other than POI and waypoints and I have already removed all of them. And reset the unit a few times. Nothing help.
Did you have all bluetooth, 3d buildings, terrain, and voice command disappeared?

I got both GarminCure3 and updater and an earlier 2.5 firmware. There are a few threads with instruction on how to getting 3790 to pre boot mode. But followed each of those methods, I still could not get the unit to be recognized by the updater.exe. I could only get the unit to show the blinking green "system" word, while holding the left corner, then after a few seconds, it went on booting the maps.
Could anyone show me how for 3790?

Also, I can get into the Diagnostic mode but I cannot find any Inventory Page like other said on the internet. Are these inventory pages in the diagnostic mode (holding the battery icon...) Any idea how to make the unit show the inventory pages?

Thanks.

I'm the same as you...I have no idea how to fix my model number and regain my lost features. I have also deleted the GarminDevice file and it simply creates a new one with the corrupted 37xx number. I think I first had this problem when I installed map 2013.10 (not too terribly long after I bought the unit). Also, I was using LifetimeUpdater, not MapUpdater as I had previously mentioned.

If you open up the XML, it looks like the data within it is generated from an external source from Garmin under http://www.garmin.com/xmlschemas/GarminDevicev2.xsd

I'm not familiar with XML so I can only make an educated guess as to what's going on. But it looks like the Garmin information is all created based on the response from Garmin themselves through that xsd.

What really frustrates me is that the myGarmin website still knows it's a 3760 (based off the serial number I'm sure), but there is no way to fix it from there

Also, you are saying you DID do a hard reset and it didn't fix the problem, right?

I have done everything I that I know including reset many times.
After I post this, I also did a multiple of reinstalling the maps and the firmware 5.0. I realize that I lose one additional feature - traffic.

I am now almost sure that it is the map/firmware update that took the missing features away. Since I did not use most of the lost features, the unit was out of warranty when I noticed that...

There is nothing wrong with the Garmin hardware. Only the software/firmware have problem(s) after the map/firmware updates. The repair/correction could just be no more than a simple, easily software solution by flashing the unit with a factory image and or offering an utility to auto detect missing features/maps, etc. and reinstall what were missing.... But instead, Garmin wants the customers to return the GPS so they can do the fixing for a charge. The repair cost Garmin wants is actually more than the market price of a refurbished 3790LMT.. then why anyone want to repair it but to just get another GPS?

I have been using Garmin for over a decade now and this is the first one I have with life time map update. This is also the one that fails. I am buying another GPS now and for sure I will give another maker a chance.

The garmindevice.xlm appears to be an "output report" generated from hidden software inside the unit and not a "config" file. Therefore, changing this file alone could be just a waste of time. The rewriting/repair to the internal config file should be very easy, but Garmin is just not offer that to the public even thought the map/firmware update could be the cause of the errors.

For sure, before the update, Express would first look at the unit's model and serial # to determine what features and maps the unit should have and upload the corresponding update(s)... I suspect that after the update, Express does not check for errors such as missing features, etc. and allows post update error(s) to accumulate causing the unit to have less and less features until the unit rendered useless. Even I lost many features at the time when I first post this. But I did have the traffic feature. But after I re-installed maps/firmware a few times, instead of getting the missing features back, they took away one more feature - traffic.

In theory, we just need to find out what is responsible for generating the GarminDevice.xml. I searched and searched in the files as best as I could but couldn't find anything.

I tried to research online but had no luck.

I do not think it is important to find out what write the xml but to just locate where the internal config file is and edit it back to factory 3790 settings. The map/firmware updates had apparently changed the settings of this file to take away features that it not supposed to, a little by little...

Since Garmin offers no help without a steep charge and the technical members of the forum could not resolve this, I think it will be just a wast of time for you and I, being non-technical on the architecture of this device, trying to resolve this thinking our "solution" could help others who has the same problem. By searching the internet, there are many out there with similar issues, but most did not even know what hit them except to reluctantly buy another GPS.

And I don't suspect you will. What is written to GarminDevice.xml at bootup is embedded in the unit's system software/firmware which is pretty much closed & encrypted and not accessible to the end-user.

To see one way to use GarminDevice.xml

look at this thread
http://www.poi-factory.com/node/40118#comment-330074

Well, that's good to know. Now we just need to know what generates the model number.

I stumbled upon TurboCCC's site and saw the RGN_Tool: http://turboccc.wikispaces.com/RGN_Tool

would this be related to the issue we're having? I can't tell unfortunately.