Thread: Nuvi 58LMT "can't unlock maps".

The message "Can't unlock maps" indicates that there's a detail map on-board which has at least one locked map tile in the *.img file. In your case, being that it's an LM (Lifetime Maps) device, its map entitlement should be supplied 'locked' but with the appropriate UNL & GMA files to allow the device to read and use the maps.

Although you don't specifically mention this, the tone of your post seems to indicate that once it does boot up fully it can operate and navigate fully normally, it that so?

Please also advise the details of all IMG files showing in the internal memory's ".System" folder, and if present, also in its "Map" folder.

All is not lost.
If you use your SD card as a clone of your device you should be able to download all the update files.
Make a copy of your garmindevice.xml from your device ,create a folder on the SD card called Garmin and paste it into it.
Disconnect your device from your PC and plug in the SD card.
Use Garmin Express to update the SD card clone and you should end up with a .system folder with the update.
You can then copy/replace the files in the system folder on your device from the SD card

Code:

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Spoiler: .system image

[Only registered and activated users can see links. ]

From you file list below it looks like the UK & ROI map update happened and the FW was also updated ,most properly a corruption occurred of the gmapprom.img,gmapprom.unl or gmapprom.gma

What you are seeing/describing is the base map gmapbmap.img without any detailed map.

The messages "No detail maps present" and "Can't unlock maps" are somewhat inconsistent. Looking at your device contents, the only detail map present in the .System folder is "gmapprom.img" with size of 711,524,352 bytes (~679 MiB) and in .System\Map is one of 162,926,592 bytes (~153 MiB) named "D4935310A.img". They are likely to be your UK detail map and the Foursquare i suppose. You should open them in [Only registered and activated users can see links. ] to identify them and check for errors.

The other possibility is that one of the "old" GMA or UNL files from an earlier version map is interfering with reading of the current detail map. You could try removing everything from the Map folder except these:

Code:

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Keep a copy of the GMA & UNL files you remove of course.

You could also try removing all the present detail maps and their associated GMAs and UNLs then replace them on the device in their proper locations with the files you downloaded from GE via the "nuvi clone" SD.