I hope to get help with my bricked 50 LMT.

1) Bricked device MODEL, Firmware version, HWID.

50 LMT, cannot access files so not sure about FW, HWID should be 2267 but must confirmed once I gain access to the files.

2) Why and how the device got bricked.

It stopped tracking suddenly while driving, since then, I only see the Garmin logo splash screen. It may be linked to the use of an SD card to restore voice command as memory was to small for that last update.

3) Symptoms: what's wrong in your device?

It always shows the Garmin logo as soon as it is under power, the power button will cycle the unit while held but has no effect otherwise, the gps stays on with splash screen on.

4) Does your pc sees your device ?

No

5) List all the procedures you already tried to unbrick it and their results and errors messages obtained.

I have tried all reset methods without success, took battery off to make sure the unit is off before attempting to connect to pc using Garmin Cure 3 and updater without success.

6) Do you have Garmin USB Drivers installed ? Garmin: USB Drivers Updates & Downloads
Yes

7) If you don't know HWID get it by Use program G7ToWin to retrieve your HWID

Can't access the files.

8) Write down if you already read or tried GarminCure3 tool - the new way to create cure firmwares for Garmin devices
How to unbrick a nüvi - step by step guide

I tried that and managed to get the "system" and after that "loading" showing but nothing happened looking at the updater, got the message "no USB device found". I also got a windows message saying "usb device unknown, usb device not installed".

9) Can you reach preboot mode? If no ,have you followed this? Garmin devices preboot mode

I tried many times putting my thumb between the G and A which seems to work one in about 20 trials, what is the exact method for this model?

10) Probably no , but do you have NV backup?

Yes, I have a backup from the device.

Thanks for your help.

11) Once you get a reply and a procedure to follow from our experts, please give an accurate reply about what you did and obtained results.