I accidentally fried my Arduino. I found this Instructable. The symptoms are the same. The board not powering on connecting USB source and the over current protector was heating up. So I removed the voltage regulator as mentioned in the Instructable. But the problem is the pins 1 and 2 of where the regulator used to be are still shorted out. That is even after removing the regulator, the pins seem to be somehow internally shorted. I tried checking the continuity on another working Arduino and found it to be not shorted. What seems to be the problem?

  • 1
    The problem that something else on the board is fried as well. Maybe the MCU itself. It would be easier to buy a new one, I guess...
    – Eugene Sh.
    Commented Jan 21, 2015 at 18:47
  • You should try running it off a separate 5V supply to see if the other parts are damaged as well. Commented Jan 21, 2015 at 18:57
  • @IgnacioVazquez-Abrams As I understand, the Vout of the regulator (i.e. 5V) pins are shorting, so it is impossible to connect external 5V to such a setup unless the short is resolved.
    – Eugene Sh.
    Commented Jan 21, 2015 at 19:01
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    What board are you using? Mega like in the instructable? Try checking the caps. Are there any visible anomalies? Charred traces e.g.
    – Gerben
    Commented Jan 21, 2015 at 20:34
  • I checked if the MCU was damaged by installing it on another board and found it to be not damaged - @EugeneSh. I am Using Arduino UNO not Mega. I found no visible damage.
    – Ray
    Commented Jan 22, 2015 at 2:36

1 Answer 1


I know it's an old thread, but others are likely to have this problem. If you check the open source schematics, there are a couple of nearby capacitors that connect pin 1 (GND) to pin 2 (+5V) of the regulator.

I would check C2 and PC2 (top right of the diagram) as well as C1 (top left of schematic diagram), and any other components you can find that bridge the rails between +5V and ground. Capacitors are more likely to fail shorted than many other components. You will have to remove at least one pin of each capacitor to test it since you don't know where the short is, or you can simply remove capacitors until the short goes away.

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