I’m having some trouble when using my ethernet shield and powering from a wall wart. I have a circuit that is working out just fine when plugged into usb, but doesn’t work when powered off a wall wart so I started doing some testing.
I powered up my arduino from both a 9v and 12 volt wall wart and everything is fine. But when I add the ethernet shield the regulator starts getting hot and the 5v line only reads 3.1 volts. If I plug this same circuit into my computer via usb everything reads fine and the sketch runs. Could I have a defective shield? I visually checked the board for shorts and it seems fine.