I tried using my Arduino Nano in a circuit, switched on power to the circuit and heard a crack and smelt a bit of burning - something shorted.
I have plugged my Arduino into my PC with a USB, the light comes on - it's detected by my PC, so it's not fried completely.
However, when I try powering the Arduino with a 12V 2A wall adaptor (it was working with that before) no lights. Is it possible I somehow fried the voltage input or ground pins - or the voltage regulator (if it has one)?