When i connect my arduino nano to windows 10; the arduino nano is powered on (the "POW" led is on and not blinking; none of the others are on) but it doesn't show up on my computer. It used to but I think I may have shorted it.

Oddly, I get a measurement of 5V coming from digital pins 2,3,4 if connected through USB or 12V if I connect external power source to V_in. These are the pins that were on before what I believe was a short. Can someone tell me what is the component that is damage and whether it is possible to fix. Thanks!

  • 4
    If you observe 12V on an MCU pin, the MCU is certainly dead. Commented Jul 9, 2018 at 13:11
  • Sometimes this happens when there is a short circuit, but does not necessarily fry the board. Is the nano touching any other conductive material? Finally, I would like to suggest that you try and restarting windows since windows at times just fails to pick up the Arduino. Commented Nov 6, 2018 at 23:57

1 Answer 1


If you were powering from 12V and shorted the 5V to GND then yes, it is all dead. The regulator will have stopped regulating. 12V will have then been sent to every component on the board. The USB chip, the main MCU, the 5V regulator - all will be toast.

You could repair it by replacing almost every component on the board, but when they're so cheap, why would you bother?

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