Arduino heating up

Development Tools IDE 1.x
1

Hey everyone,

I'm pretty new to Arduino, so I apologize in advance if there's a really simple answer out there that I wasn't able to find. :slight_smile:

I've been using my Arduino mainly to test LED's and other small components, so I've kept it plugged into my laptop without any issues until now. Recently, I built a project using a receipt printer (Hello Printer), so it was necessary to plug the Arduino (connected to an ethernet shield and the printer) into a wall socket. Almost immediately, both boards began to heat up to the point where it hurt to touch. I unplugged it as quickly as I could, and there didn't appear to be any damage. My first thought was that I was using the wrong adapter, so I checked and confirmed that it is a 9v AC-DC adapter. My next thought was that the printer was using too much power, so I unplugged it and tested a simple LED blink program. That made the Arduino and the ethernet shield heat up as well. Finally, I tried the LED blink program in a different socket, only to have the same results. I am aware that it's normal for the board to heat up slightly, but this seems a little extreme.

What should I do? I'm all out of things to try.

Thanks in advance!

2

Have you tested it without the ethernet shield attached?

3

Yes. I've the blink program with and without the ethernet shield.

4

If the '328 chip gets hot all by itself, (nothing else attached) that's usually a good indication you have an output pin or several.
Only a matter of time until it fails.
Get another chip before your current one dies.

Or is something else getting hot?

5

same when using usb power?

6

Power source doesn't matter. If the ATMega chip gets hot, that's usually a good indication you have an output pin or several are damaged.

7

The Ethernet shield will get hot. It will also cause the Arduino's on-board regulator to get hot when powered through an external adapter. The chips tolerate more heat than your finger tolerates. So "hot to the touch" isn't necessarily a good measure of "too hot."

As CrossRoads points out, if nothing is attached and the ATmega328 gets hot, then it is damaged.