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, 2017 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, 2017 at 19:01
  • Did you put a resistor between the Arduino and the gate of the mosfet?
    – Gerben
    Apr 28, 2017 at 19:53
  • 1
    Dyd you try to flash in a simple Blink using the onboard LED? You should go very basic when things start to fail like that. Also, disconnect the 12V power supply and power your nano from USB only when running this simple test: the voltage regulator should not be part of the circuit when powered from USB and you can start factoring things out. Apr 29, 2017 at 1:45
  • 1
    Yes, I did that - the device is not responding. Rxd/Txd pins are dead as well. I'm putting this down to overheating voltage regulator inside an already toasty-hot closed compartment.
    – user2497
    Apr 29, 2017 at 1:49


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