Nano stopped running/uploading sketches

I was following a tutorial regarding some new Hall sensors. After trying out a few changes in the code, the arduino software stopped uploading to the board. The code which was already on the Nano also isn't running anymore (I know this because a LED should light up when I pull a particular pin to GND).

After inspecting the Nano, here is what I observe:

  • In Arduino software, after compiling the code, it's stuck on 'Uploading'.
  • When uploading, the TX led blinks a few times briefly then stays off.
  • No burned components or traces visible (at least to me, I haven't had much experience identifying these)
  • My laptop still recognizes the Nano
  • Doesn't upload on any other USB ports either
  • When plugged in USB port, the PWR led lights up, but sketch doesn't seem to be running. Same thing with a 5V power bank.
  • Pin Vcc to Pin Gnd reads 5.1V
  • Weirdest thing: All GPIO except pin 13 have a small voltage of about 1,18 to 1,3V, it fluctuates between these values but it's the same for all pins. For pin 13 it reads about 0.57V.

Does anyone know what might be possible faulty or burned? I'm hoping if possible I can repair it myself

When you press reset button on nano, does the LED flash?

Were you playing with the WDT? WDT resets cause problems with the nano bootloader.

Hi DrAzzy,

Nothing physically happens when I press reset btn. Haven't touched watchdog either.

Anyone who knows what went wrong or knows what part might be burned?

Try reburning the bootloader with an ICSP programmer. If that fails (and you're sure it's not a wiring issue - it's very easy to get a connection wrong or have a loose wire or something, based on forum posts here), trashcan it - a new nano is only a few bucks, so it's not worth spending much time on.