Quote Originally Posted by kimis View Post
Have probably similar case like some others had here with Fenix3/6
Indeed, this is likely another example of soft-bricking from which it won't be easily recoverable, as experienced with other watches. Again, it's due to the unusual firmware layout and operation - no ramboader is present in fw, rather the first section has bootloader/u-boot (fw_0505.bin) which is flashed DIRECTLY to region 5. In conventional Garmin devices, rgn5 is protected from direct flashing and is exclusively written to "onboard" by rgn12 - a virtual region flashed directly by "boot.bin" (the ramloader component of fw).

1) Bricked device MODEL, Firmware version, HWID.
MARQ Captain (American Magic) FW: was 25.85, tried all other starting 3.10, HWID 3248 (from garmindevice.xml) but FW for Captain goes as 3246
I haven't looked extensively but only found the 3246 and 3247 firmware, both V20.50. If you'd like me to make recovery files for you then please post a link to the 3258 V25.85 for me to use.

2) Why and how the device got bricked.
wrong FW flashed/uploaded, from MARQ Aviator, id 3247
now do not remember was it uploaded with updater.exe or has been stored directly over USB
I think it must have been done as an RGN using Updater.exe. Usually Garmin devices will ignore a 'foreign' GUPDATE.GCD which has been written to its internal memory. That's due to the device detecting a HWID mis-match.

5) List all the procedures you already tried to unbrick it and their results and errors messages obtained.
Have tried to upload almost all FW versions by converting gcd to rgn with RGNTool
QuickCure.rgn does not uploads over (web)updater
RGN_Tool may not handle this 'unusual' fw correctly and any extracted RGN or individual BIN files might be imperfect. Maybe gwf.exe can cope with it though: [Only registered and activated users can see links. ]
kunix's QuickCure3.exe is a universal ramloader for rgn12. Your watch doesn't work that way as i explained initially above, it has rgn5 flashed directly. In any case, your watch has been bricked by a wrong fw. Cure fw, including QC3, is only useful to recover a device that can't boot because an essential file is corrupted and can't be loaded during the boot-cycle. Cure fw's sole purpose is to re-enable access to Mass Storage Mode so a bad file can be removed or the internal file system to be re-formatted in extreme cases. Simply not applicable in the case of any device bricked by a wrong fw flash.

8) Write down if you already read and tried everything in these two threads: GarminCure3 tool - the new way to create cure firmwares for Garmin devices and How to unbrick a nüvi - step by step guide
garmincure3 does not recognize gcd
A known issue because of the watch's fw composition. Regardless, GarminCure3.exe also isn't useful as explained above.

9) Can you reach preboot mode? If no ,have you followed this? Garmin devices preboot mode
It is kind in a permanent preboot mode
Yes, it's known as recovery mode in such devices and is much the same as 'preboot mode' and 'Garmin mode' in other more conventional devices. Usually recovery mode in a healthy device of similar operation is reached via a button press sequence, however usually a Garmin device that is firmware-bricked but still powers on will default to preboot/recovery mode.

10) Probably no , but do you have NV backup?
m?
Not applicable for your device anyway.
.............
After you've directed me to the HWID 3248 "American Magic" fw we can try some recovery methods. Or you can try yourself with an RGN file made using gfw.exe (decompile the GCD to BINs and re-compile them to an RGN). Previous users' experiences with similar fw types aren't encouraging as you're aware, but yours has a different cause of 'bricking'.... so there's still hope.