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Raspberry Pi 3 B+ Short Circuit

ibrahimgarip

Hey i got a new raspi almost 1 week ago and yesterday I try to add cooler fan.

Fan was working 5V and think i can get from pinout. when i was a connect, raspi was restart.

I try again when its open ( Wish i shouldnt image)  and bom, raspi gone. Its not working anymore. Only red light and nothings happening.

I think maybe it can be a short circuit and i measure with multimeter the polyfuse its 0 ohm without power, 0.13 Ohm on power.

I change the sd card and software.

But nothings happened.

What can i do ?

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  • There is the remote chance you connected the fan to the wrong pins or at an angle which allowed the 5V supply to short over to the 3.3V line or to any one of the GPIO pins, or the ground line of the fan may have been inadvertently connected to a GPIO. Running a fan from the 5V GPIO line in itself is not a problem if properly connected, provided the current consumption is only modest.

     

    As states, and I too can vouch for, the Rapsberry Pi GPIO is fragile.

     

    To troubleshoot, I would:

    - Remove all connected accessories from the Raspberry Pi to minimise chance of faults in connected equipment causing the polyfuse to open.

    - Wait some time to allow for the polyfuse to cool and re-form. Repeated tripping of polyfuses leads to degradation and earlier tripping.

    - Power the board with a known good cable from another supply in case it is a power supply fault.

    - Reimage the SD card in the off chance that an unexpected power-down corrupted it to the point it would not boot.

     

    In terms of your measurements, you cannot directly measure the resistance across the polyfuse when the Raspberry Pi is powered - in circuit resistance measurements will not be accurate due to applied voltage and provide misleading results.

     

    You are best to measure the 5V from the USB port side to see if the Pi is getting a full (approximately) 5V or if the polyfuse has opened (in which case it will read a lot less). Normally if the polyfuse has opened due to a drastic short, you will not get any power lights at all or maybe just a short "blink".

     

    However, I suspect you might not have shorted the Raspberry Pi at all and instead may have killed it through Electrostatic Discharge (ESD). This can happen if your body develops a static charge and you touch a GPIO pin, thus discharging through the SoC and burning it through. This is why you shouldn't handle electronics unprotected, especially if you're around carpet or wearing wool or near a cat, etc ...

     

    - Gough

  • in reply to Gough Lui

    Firstly i want to say thank you (btw Everyone answer me)

    I just wait for the polyfuse 4 days, but nothings happen. Still just red light, not blinking lighting properly.

    I measure the voltage from PP7 and PP3(plus sd card case), get 4.91V, its has to be enough it think image.

    I try again the change software, try to boot from usb. Nothing worked. He says "Leave me with my loneliness".

    Idk what can i do, its too expensive in my country image and i need it in my project.

Reply
  • in reply to Gough Lui

    Firstly i want to say thank you (btw Everyone answer me)

    I just wait for the polyfuse 4 days, but nothings happen. Still just red light, not blinking lighting properly.

    I measure the voltage from PP7 and PP3(plus sd card case), get 4.91V, its has to be enough it think image.

    I try again the change software, try to boot from usb. Nothing worked. He says "Leave me with my loneliness".

    Idk what can i do, its too expensive in my country image and i need it in my project.

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