Hi guys,
i am asking for your advice on repairing the Xiaomi M365 scooter controller.
Chronology:
1) I tried to strengthen all the original Mosfets by replacing them with NCEP01T18.
2) I probably overlooked the short circuit caused by my soldering and when I subsequently connected the controller to the battery, all the Mosfets burned out (visible cracks).
3) I replaced all the Mosfets again (I foolishly hoped that only they were damaged) and checked for possible short circuits caused by soldering.
4) During further attempts at connection, individual Mosfets gradually burned out when the current load increased (by adding speed).
5) I found and gradually replaced other damaged components on individual phases (most often these were resistors 56R, 68R), I also replaced all the T4 (1N4148W) diodes and Mosfet drivers.
All standard components on all phases that I measure, or possibly unsolder them to measure them, now seem to be ok, however on phase A, if I put a little load on the motor, the second Mosfet always burns out (high side one?).
I am attaching picture, a schematic and a video from a thermal camera, where the Mosfet burns out.
I am at the end of my ideas and my last suspect is the motor - with another controller it runs without problems at idle, but stuttering under load (I hope it could be bad in the wiring/connectors...).
I will be very grateful for any advice.
Thank you!
i am asking for your advice on repairing the Xiaomi M365 scooter controller.
Chronology:
1) I tried to strengthen all the original Mosfets by replacing them with NCEP01T18.
2) I probably overlooked the short circuit caused by my soldering and when I subsequently connected the controller to the battery, all the Mosfets burned out (visible cracks).
3) I replaced all the Mosfets again (I foolishly hoped that only they were damaged) and checked for possible short circuits caused by soldering.
4) During further attempts at connection, individual Mosfets gradually burned out when the current load increased (by adding speed).
5) I found and gradually replaced other damaged components on individual phases (most often these were resistors 56R, 68R), I also replaced all the T4 (1N4148W) diodes and Mosfet drivers.
All standard components on all phases that I measure, or possibly unsolder them to measure them, now seem to be ok, however on phase A, if I put a little load on the motor, the second Mosfet always burns out (high side one?).
I am attaching picture, a schematic and a video from a thermal camera, where the Mosfet burns out.
I am at the end of my ideas and my last suspect is the motor - with another controller it runs without problems at idle, but stuttering under load (I hope it could be bad in the wiring/connectors...).
I will be very grateful for any advice.
Thank you!
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