I would like to ask for some help with RPi 3B+. It was working for three weeks and for some reason not starting anymore. I tried to wait for three day long as suggested for the polyfuse to rebuild, but nothing again. What I did before one program that I use for is reef-pi, and because my temp sensor sensed the wrong temp, I try to pull out and re plug the wire, (3.5 mm stereo jack) when I did that the RPi get shorted on some way, and now I can not restart anymore.

I have tried with two new SD cards but nothing improves. I have measured GPIO port pin 1 and I got the 5.25 volt. What does that mean? Is the RPi working or just something else?

This is my second RPi, the first RPi's SD card slot just fell off the board.

  • Do you have a monitor connected or can you just observe green "SD access" LED flashing when booting? – Jan Hus Aug 5 '18 at 15:30
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    monitor connected but no sd green led flashing – j sz Aug 5 '18 at 15:41
  • OK, now for stupid question . Is the red LED on ? No green LED activity means no reading of SD. Do you have a spare SD to load clean OS onto it? SD go bad and there is not much to do to recover them. – Jan Hus Aug 5 '18 at 18:51
  • yes the red led is on and i try 3 different sd card,+usb stick – j sz Aug 6 '18 at 18:59
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    Sounds like you toasted it. – Dmitry Grigoryev Aug 14 '18 at 14:53

If pin 1 is measured at 5V the Pi is damaged beyond repair.

Pin 1 should be 3V3 and is used to power the SoC which will now be dead.


  • pin 1 is 5v on gpio right side – j sz Aug 5 '18 at 15:40
  • Right side relative to what? Pin 1 is pinout.xyz/pinout/pin1_3v3_power and it's 3V3. Are you sure you're not measuring physical pin 2? – Dirk Aug 5 '18 at 16:45
  • @Dirk: pin 1 is the one with the square (as opposed to round) pad. – Seamus Aug 5 '18 at 17:06
  • you r right pin 1 i call but that is pin2.Physical pin – j sz Aug 5 '18 at 17:14
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    Dear all, please be reminded of the "be nice" policy. I would think that Seamus' comment was posted in good faith and might actually be helpful to the OP. @jsz it would be most helpful if you could stick to the pinout and pin numbering as linked in the answer. Otherwise it's highly confusion and leading to an unneccesary back and forth in the comments section. – Ghanima Aug 5 '18 at 20:35

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