Bricked Swan K1 Pro

Hi to all,
I tryed to upgrade the swan k1 pro firmware following the youtube video by HEQ but after “update successfull” but I cannot get it to work.

I followed this video: Swan K1 Pro Firmware update instructions - YouTube

Now when I connect the swan k1 pro board to the computer it disconnect and reconnect in loop. QGroundControl cannot detect it. I can only upgrade again the firmware from the “Firmware Section” in the QGroundControl but I get same loop’s results. I tryed to use QGroundControl on two different computer (windows10 and linux) , I changed 3 usb cables but nothing change.

These are the videos where I try to restore the firmware:
Vid01: Vid01 - YouTube
Vid02: vid02 - YouTube

Is there a way to get it back working? Am I doing something wrong?