Thread: Garmin Fenix 6X PRO Bricked :(

The command prompt syntax for gfw.exe to build an RGN from BINs is "gfw.exe bldfldr <folder with input .BIN files> <output .RGN folder>".

Regardless, the program has detected that 0x0E (rgn14/fw_all.bin) has an invalid format. This is totally weird firmware, it seems 14/0E is actually not written as a normal Garmin BIN file but is in fact another RGN which itself contains a BIN. It's a mystery to me how this is processed by the device itself, sorry but this is quite above my level of expertise. I suspect none of those older tools are able to deal with such a novel container or with rgn5 being directly flashable from a GCD file rather than via rgn12. In the latter case i'm thinking that rgn5 is indeed protected against both external direct flash and dump. Also, rgn14/0E is likely unreadable by GPSdaemon because of its unusual structure, an RGN containing a BIN.

Although i'm not hopeful considering the history so far, you could also try loading the V20.50 fw by running WebUpdater in command line with the watch connected in preboot. i.e. "<path to webupdater.exe> /i /autorun usb /upload_file rgn=<decimal#> path=<path to BIN file>"

Examples:
C:\Garmin\WebUpdater\webupdater.exe /i /autorun usb /upload_file rgn=14 path=C:\Temp\02BD--0CDB-0802.bin
and
C:\Garmin\WebUpdater\webupdater.exe /i /autorun usb /upload_file rgn=5 path=C:\Temp\0505--0CDB-0802.bin

Of course, in the above examples webupdater.exe would be in the folder C:\Garmin\WebUpdater and the BINs in C:\Temp. You should use paths as appropriate for your placements.