Pysense bricked? Pin voltages wrong (0.2V instead of 3.3V)



  • Pysense and Lopy4 worked well, until I started implementing a lipo battery charged over the USB port by a powerbank. The lipo charged well as indicated by the red LED on the Pysense. And then.. I guess that following charging the powerbank shut off and later switched on again. Since then the Pysense does not work well (the Lopy still gives a heartbeat when powered over a breadboard). My observations:

    1. If I plug it in the board is recognized in Atom, but it cannot connect (Atom remains in "Autoconnect: Connecting on COMXX...")

    2. The voltages on the Pins are not correct.
      Over the 5V and GND I measure 3.6V instead of 5V.
      Over the 3V3 and GND I measure 0.2V instead of 3.3V
      The external IO headers give 3.3V (1-2), 0.2V (1-3), and 3.3V (1-4).
      The output to the JST connector for the lipo is 4V.

    Reset over the button does not help. Updating the firmware does also not work (Zadig does not give an error, DFU indicates "No error condition is present" and exits with "Done!". Different USB cables and USB ports result in identical observations.

    It seems there is a hardware issue that results in a lower voltage on the part of the board that powers the Lopy. The Pysense shows no signs of physical damage.

    Did anyone experienced the same and managed to solve this?
    Any ideas on what could have caused this status?
    Any ideas to fix it?


 

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