I had a strange fault on a makerx A200 after the hubmotor sheared the key and rotated the axle ½ a turn, shorting out the phase wires.
After fixing the motor it ran really poorly and having trouble starting the right way (sensorless) and often cogging like crazy. I checked phase outputs, gates, current sensors etc. with an oscilloscope and to my limited knowledge everything looked good or at least the same between phases.
Then I noticed that "Tac" was counting up even when the motor was stationary. Thus suspecting that the stm32 was broken in some way. And sure enough after changing it the esc worked good again (on the bench at least).
TL:DR, shorted the phase wires and that fried the microcontroller somehow
Do anyone have any theories on what could have happened? I can't imagine what could fry the stm because of the phase wires shorting intermittently. Hall sensors was not connected to the esc at the time.
Would it be a good idea to sticky a "hw faults and their solutions" topic where we could post faults and the solution that fixed it. (I don't think there is anything like that atm?)
So the motor phase wires were shorting together? The common failure there would be if one phase was driven to VBat and the other to 0V and now you have a short across the battery. Only killing the microcontroller is weird.
They were intermittently shorting to the axle (i.e indirectly shorting to each other) so the motor would sometimes run but very badly ofc.
Phase voltage in the frame should not make any difference since the esc is isolated from it. So I really don´t know what happened.