Looks like the arduino board is damaged. RCA seems to suggest that the 5V converter is either putting out the full 12V (meaning it is itself shot) or you have connected it to the wrong pin on the arduino.
Looks like the arduino board is damaged. RCA seems to suggest that the 5V converter is either putting out the full 12V (meaning it is itself shot) or you have connected it to the wrong pin on the arduino.