I was trying to make a custom power source to supply power to the micro usb port on the Pi B+ and I reversed the + and - by accident and then smelled something like burned plastic. The SD card doesn't seem to boot anymore but I changed the SD card with a new one and now it seems to work still.

Is this PI still useable? Does the Raspberry Pi 3b+ have reverse polarity protection built in?


There is no reverse polarity protection on the Pi3B+ although earlier models had an "ideal diode" (whether this would provide reverse polarity protection is doubtful - this is there to prevent back-powering). The schematics are available for download.

The Pi3B+ (and similar) do have a polyfuse and transient protection diode which probably conducted and may have protected the Pi (but I wouldn't try it myself).

  • 1
    I am a newbie in schematics so I'm asking here. – bakalolo Sep 6 '18 at 4:00

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