i've got a bit of a problem with my Arduino UNO.

So coming back to my (pretty basic) build after a bathroom break, I go to un-assemble my circuit (on the breadboard) and grabbing the LED causes a static shock.

Since then I haven't been able to get any power to come out of the Arduino to the breadboard circuitry.

I have tried:

  • Different Breadboards
  • All new parts, LED's/cabling/buttons/resistors.
  • Different power and ground cables (from Arduino to breadboard)
  • Giving the Board more time to 'cool down' (I heard there was a temperature based reset device?)
  • using the 3.5v output (I'm not sure if by doing this i should remove the resistor? i'm VERY new to electronics
  • using the alternate ground input

Looking around here for 'shorts' or 'damaged Arduinos' returns mostly results about non communication to the board. the difference here is I can absolutely still upload programs to my Arduino and then run them (I've only tried the pre-existing blink, but i don't think there is any difference). And my computer's USB ports are also fine. So if there is a duplicate question i apologize, but i haven't been able to find anything related.

Any help would be much appreciated!

  • 1
    What does “get power to come out of the Arduino to the breadboard circuitry” mean? Which output pin isn't working? Have you tried some other pins? Feb 24, 2017 at 3:34
  • But you can still upload and run the blink sketch on this 'damaged' Uno ? WIre a led (it's polarity sensitive) with a series resistor say 330R between the GND pin and +5V pins on the Uno to show if you have power there, then check the connections between the Uno and the breadboard.
    – 6v6gt
    Feb 24, 2017 at 8:10

1 Answer 1


If you got zapped touching an LED and the circuit doesn't work any more, and since you're sure the Arduino uploads programs OK, then either the LED (or something else on your breadboard) or the pin driver within the Arduino is probably damaged.

  • Try changing the LED.
  • If that doesn't work, try changing the pin(s) the sketch uses to talk to your breadboard, rewire your breadboard to use those pins, and test again. If it works this time, the pin driver was probably damaged.
  • If there are any other components (e.g., not wires or resistors) on the breadboard whose failure might cause the LED not to light, replace those and test again.
  • If replacing the external components doesn't fix it, and if your Arduino's MCU is a 28-pin chip in a socket, a new one with the bootloader already loaded into it typically costs $5-$6 in the US.


...i have listed all these things as already tried.

Right - I read right past it. :( So you've done the right things (except no mention of testing other pins) so I'm not sure what your question is. The title asks about the board's 5v supply but that must be up b/c your board uploads and runs Blink. That really leaves only the the pin driver(s) you were using when you zapped it.

You can salvage the board by testing all the pins in their input, output, analog, and other functions, and make a note of what capabilities have been lost. Clearly not all of them - pin 13 still works, for instance, because Blink worked. You can't repair damage internal to the chip without replacing it, and I would always consider it suspect, but it will be fine for many hobby uses if you just avoid the damaged functions.

  • In my OP i have listed all these things as already tried. Looks like i'll just have to pick up a new Arduino then :( Thanks! Feb 24, 2017 at 21:49

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