Thread: IMPORTANT! If you want HELP in case of a bricked Garmin device, please follow this

An RGN file is not exactly the the same as a GCD file. The latter had some additional data and it's initiated by the device itself on successful booting to update firmware, whereas the former has to be manually flashed in preboot using updater.exe, but other than that the purpose and indeed the contents of the files are similar. The file made by GarminCure3.exe is an RGN file, whether that's as cure or original firmware.

Before you need to look for addition files (which cannot help you just yet) we need to establish exactly what you've done and in what order. Did you follow what i wrote in post #181? i.e. First load cure fw, then format with RMPrepUSB, finally load original fw. Also where did you get the .System folder, did you make it yourself or load it from a backup? Don't put any files or folders from any source in the memory at first after loading the original fw, if it boots after doing those things i mentioned in correct order just connect to GarminExpress for missing files and then separately load a basemap. If it doesn't boot then manually create an empty 'Garmin' root folder as i said, nothing else for now.

If you missed doing something or aren't sure what you did then please do it all again in order: load cure RGN fw> format > load original RGN fw > try to boot before proceeding.