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A accidentally connected the 5V power supply to ground (pin 34) on my Raspberry Pi 3. It immediately rebooted and seems to work fine, however, I now can't seem to get any input. Even simple things like a button don't seem to work. The same GPIO pin will still work as an output - e.g. to control an LED. Have I somehow fried the input functions? Everything else seems to still work fine. I am a novice as far as electronics goes. Appreciate any help you may have.

  • If you connected the 5V power (exactly what?) to Gnd, you would have shorted out the power supply. This would reset the Pi but should not cause any damage (as distinct from connecting it to a GPIO pin) unless the traces on the board were damaged. You then talk about "The same GPIO pin" (which?) – Milliways Mar 26 '17 at 22:49
  • I think this is what happened (shorting the power supply). After another reboot and redesigning my project, it all seems to work fine now. I think I got lucky this time! – Pi-Rookie Mar 27 '17 at 3:21
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There are at least two ways to test your GPIO. Both programs should be run with nothing connected to the expansion header.

  • wiringPi's pintest utility
  • pigpio's gpiotest utility

gpiotest is slightly more thorough.

gpiotest with all gpios okay.

This program checks the Pi's (user) gpios.

The program reads and writes all the gpios.  Make sure NOTHING
is connected to the gpios during this test.

The program uses the pigpio daemon which must be running.

To start the daemon use the command sudo pigpiod.

Press the ENTER key to continue or ctrl-C to abort...

Testing...
Skipped non-user gpios: 0 1 28 29 30 31 
Tested user gpios: 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 
Failed user gpios: None

gpiotest showing failed gpios.

This program checks the Pi's (user) gpios.

The program reads and writes all the gpios. Make sure NOTHING
is connected to the gpios during this test.

The program uses the pigpio daemon which must be running.

To start the daemon use the command sudo pigpiod.

Press the ENTER key to continue or ctrl-C to abort...

Testing...
Write 1 to gpio 17 failed.
Pull up on gpio 17 failed.
Write 1 to gpio 18 failed.
Pull up on gpio 18 failed.
Write 0 to gpio 23 failed.
Pull down on gpio 23 failed.
Write 0 to gpio 24 failed.
Pull down on gpio 24 failed.
Write 1 to gpio 27 failed.
Pull up on gpio 27 failed.
Skipped non-user gpios: 0 1 28 29 30 31
Tested user gpios: 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
Failed user gpios: 17 18 23 24 27
  • I think I'm fine now, but I really appreciate this response and will file it away for future reference. Thanks for your help. – Pi-Rookie Mar 27 '17 at 3:22

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