I have a raspberry pi 3 B that apparently stopped working after a thunderstorm. When it's plugged the red power led turns on but I can't boot the OS. I checked the voltage on GPIO pins and I get:

  • 2.12v on 3.3 pin
  • 4.7v on 5v pin

Also I checked the voltage across the polyfuse F1 and I get 4.7v on each side.

I noticed that when the board is plugged, the lan9514 chip becomes very hot.

What else could I do before throwing it away?

  • why are you focusing on only the hardware part of the Raspberry Pi?
    – jsotola
    Commented Sep 26, 2021 at 20:18
  • 2
    because the voltage is wrong. Also I tested it with a working sd card from another pi. what else should I focus on? Commented Sep 26, 2021 at 20:25
  • 1
    If the green light doesn't do anything with the card in and the card works in another Pi, something is probably busted.
    – goldilocks
    Commented Sep 26, 2021 at 20:35
  • Write a new OS image to a fresh card and try that first. Commented Sep 26, 2021 at 20:59

2 Answers 2


The below-spec voltages aren't promising, but it's also possible your SD card has been "zapped". If you have another RPi, try booting it from this SD card. If not, flash a new SD card, and try booting your misbehaving 3B with it.


Low voltages are probably due to the fact that the LAN chip is getting hot. It draws so much current, that not enough is left for the rest of the system.

There is a chance that removing the defective chip could get the rest of the system working. The best would be to desolder it, if you have the equipment. Cutting legs one by one with an exacto knife could work too, but there's a chance you'll scratch the PCB in the process and damage it. In both cases, there is no guarantee that the board will work without the chip, but if you're going to bin it anyway, you lose nothing if you try.


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