I'd made an LED driver, and fed both the LEDs and nano clone from 12V. The 12V switched power supply is of dubious quality. The nano itself read a pot, and wrote PWM values on three pins. It has run on-off for 2-3 months. Not long. Now it's dead - my PC does register the serial device on the nano, and the power LED comes on. Apart from that, there's nothing that works.

Before I replace it, I'd like to know if the most likely culprit was my feeding 12V into VIN. Overheating voltage regulator? The LEDs got a bit hot, ~40°, and the nano was in a box with no airflow.

  • How did you connect the leds? – Gerben Apr 28 '17 at 18:53
  • They were connected through 3 2N7000 MOSFETs, they didn't pull power from the nano. I have considered if they exceeded their rated current, but am unsure. IIRC, it's a 10V MOSFET, which I turned on with a 5V signal. The rated current is 200mA max. In any case, would a burnt MOSFET murder my nano? I've heard the act like shorts when they die. Please apply cluebat. – user2497 Apr 28 '17 at 19:01
  • Did you put a resistor between the Arduino and the gate of the mosfet? – Gerben Apr 28 '17 at 19:53
  • Yes, 220 ohms for good measure. I know the 2N7000 doesn't surge. I checked the MOSFETs, and all LED channels (R, G, B) work. It's just the nano that's dead. – user2497 Apr 28 '17 at 20:11
  • You could try reflashing the boot loader using a separate Arduino. Have you measured the voltage of the power supply? Some are only 12V when under load, and can go as high as e.g. 18V when there is no or minimal load. – Gerben Apr 28 '17 at 20:51

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