Raspberry Pi 4, probable short onboard

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  • kaput
    Member
    • Jun 2024
    • 18
    • Sweden

    #1

    Raspberry Pi 4, probable short onboard

    A few days ago, I smelled magical smoke, but couldn't pinpoint the source. Now when trying to 3D print something, Octoprint wouldn't respond, and I soon found that the stepdown powering the RPi 4 running Octoprint had burned out. Assuming that was where the smell came from.

    No idea if the stepdown failed and took the Pi with it, or if the Pi failed and took the stepdown with it.

    Measuring resistance between ground and the 5V line on the Pi, I get 0.2 ohms, more or less a full short.

    There's no visible damage to the RPi, checked the circuitry around the power input port under the microscope. See attached overview images, I've been closer when inspecting it. The stepdown was good for 5 amps, one would think that 5*5 = 25 watts would leave some traces, at least if the Pi failed and took the stepdown with it.

    Before starting to desolder components and testing them one by one, I'd love to know if some components are more likely to fail than others. Maybe someone here got that kind knowledge of the RPi 4, or any other tips for troubleshooting this?

    Regrettably I've got no thermal imaging camera, so powering the Pi with limited current and looking for hotspots is out of the question.
    Attached Files
  • stj
    Great Sage 齊天大聖
    • Dec 2009
    • 30911
    • Albion

    #2
    so this buck convertor - is it part of the pi or a seperate thing?

    Comment

    • stj
      Great Sage 齊天大聖
      • Dec 2009
      • 30911
      • Albion

      #3
      https://datasheets.raspberrypi.com/r...schematics.pdf

      Comment

      • kaput
        Member
        • Jun 2024
        • 18
        • Sweden

        #4
        Originally posted by stj
        so this buck convertor - is it part of the pi or a seperate thing?
        It's a separate thing, it converted 24VDC to the 5VDC the Pi wants.

        Comment

        • stj
          Great Sage 齊天大聖
          • Dec 2009
          • 30911
          • Albion

          #5
          so test the pi with 5v

          Comment

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