Your browser does not seem to support JavaScript. As a result, your viewing experience will be diminished, and you have been placed in read-only mode.
Please download a browser that supports JavaScript, or enable it if it's disabled (i.e. NoScript).
undefined
Can you try erasing the firmware on the board that is not connecting over USB and seeing if, after it is powered won and back up again. it shows up as a USB device (BOSSA programming port under windows for example)