MKRZERO unreachable after updating boot loader

Official Hardware MKR Family MKR Zero
1

After visiting the link (Overview | Installing CircuitPython on SAMD21 Boards | Adafruit Learning System)
and following all the steps to upload the updated boot loader on the MKRZERO board , The red blinking led on the board turned off and windows can not see the port connected to MKRZERO. Any help by how to reset the MKRZERO to its old boot loader or if there any hard reset to the bord .

2

fouadagha:
After visiting the link (Overview | Installing CircuitPython on SAMD21 Boards | Adafruit Learning System)
and following all the steps to upload the updated boot loader on the MKRZERO board , The red blinking led on the board turned off and windows can not see the port connected to MKRZERO. Any help by how to reset the MKRZERO to its old boot loader or if there any hard reset to the bord .

wire the MKR to programmer, then in IDE Tools menu select MKR Zero and Atmel EDBG programmer and Burn bootloader.

EDIT but you don't have a programmer. you used a sketch which replaced the bootloader.

3

Thank you for your relaying,
i followed all what you said but i don't get any result, plz can you send more explanation?

4

There is a hardware format?

5

fouadagha:
There is a hardware format?

you need a programmer device to flash bootloader if the flashed bootloader doesn't work

this usually doesn't work. for me it worked once to rescue my MKR