This issue still affecting users using M140 S0. Can you share the end script for this printer?
I found the issue executing the procedure. If it still failing for you guys, try another usb thumb drive.
I recommend smaller ones such as 4GB or 8GB.
I used the 8GB microsd with the original usb adapter and it worked. A soon as you see one led coming on you can stop pressing the reset button and it will load the kernel from usb to flash memory and fix the issue.
It tooked me 4 hours, but finally I have it working again.