Could my Arduino have been damaged

Hi,

Please give me a suggestion.

I was working on a project and at some point shorted the Arduino Nano by bridging its 5v and ground :frowning:

Now all the digital pins except 13 produce only 2v when made high.

Is there any explanation for this?

Best wishes

Simon

"He's dead Jim!"

Shorting 5V to ground is not going to damage the arduino per-say. It could put strain on the regulator or the USB supply. However it would not explain what you are seeing, I suspect something else was wrong as well. Were their inputs feeding voltages into the pins when there was no power on the chip? That could do it.
Do those pins still work as inputs?

Just the other day I had shorted 5V to GND on the breadboard that I use with my Nano - and I smoked the Schottky between 5V and V_usb. I guess if the Schottky failed then it failed short*, because the Nano still programs OK and still operates with my external 5V supply, too.

Note: Shorted supply is one thing and reversed supply is another.

(* I should check if it still drops 0V3. I wasn't using V_in, but I assume that my 5V reg is probably OK.)

+++ OK, I checked it, and it is resistive (5V1 in with 3.8V on the "5V" terminal). So, I'm getting by on the ragged edge. I don't have have any smd schottky diodes, I may work in a SO-type. [I could short it out and not plug in the usb with V_in connected. I had been going back and forth with it between the PC and the bench.]

Note: Shorted supply is one thing and reversed supply is another.

Even a reversed 5V line is not fatal, providing you don't let it happen for very long and have a current limited supply for less than 1A.

Grumpy_Mike:
Were their inputs feeding voltages into the pins when there was no power on the chip? That could do it.

If it was on aref could it throw the default 5v reference off. I left the breadboard supply on after I disconnected the 5v pin and it looked like the board was still on but the "on" LED was very dim. I promptly disconnected the power supply. When I measure an analog sensor input it reads about 300mV off. This messes with my readings for a temperature sensor library that rely on a known aref voltage. I don't know if this is from voltage inaccuracies or from damage that was done. This is all while using the the default aref setting. Also while using the defaults, if I pull up the aref pin with the 5V supply the readings correct themselves. The readings are also correct if I use the external aref settings.

I made exactly the same mistake. I briefly (2 or 3 seconds) shorted the 5v pin to ground on my nano whilst it was plugged into my computer. The Mac came up saying that a USB device was trying to draw too much power and so had been disabled. I would think that the fast reactions of the computer would have protected the arduino, but it now seems completely dead. No power light when plugged into any of various computers and USB-based wall warts. Obviously, I removed it from the breadboard for these tests so as to ensure there weren't any other problems I hadn't notice.

I can't find any visible signs of heat stress on the board. Any tips or advice?

Sorry for necroposting.

  1. Don't do it again 8)
  2. Get a new one to continue work
  3. Keep the old one and inspect it / identify damaged parts / try to replace parts when you have time to kill

And it's not called necro-... anymore. At least according to Terry Pratchett's books we should call it 'post-mortem'. So Necromancy would be called 'Post mortem communications'. And this was a weak attempt to be funny btw.

I would think that the fast reactions of the computer would have protected the arduino,

No not always.

I can't find any visible signs of heat stress on the board.

No you will not on a lot of dead chips.