We had a motor stop in flight, this was in a coaxial setup, so the aircraft was able to land safely. In the flight logs the motor RPM drops down to zero, but the error count never increases. The error when trying to start the motor again is this:
00000010_01100001 Run 2 Hardware fault Refer to the Hardware fault of the Idle task.
We tried to re-calibrate the motor which only produces the following:
00000001_10000001 Hardware Test 1 Hardware fault Refer to the Hardware fault of the Idle task. This bit is usually set together with other bits. Check the other failures listed below.
What can be the cause of this and what should we look at to try and resolve this?
It means that something has broken in the power stage. It could be caused by a poor connection of the motor wire or a short circuit on the board. Please check visually, and then check if the MOSFET transistors are alive. You can also check the driver chip. If it gets very hot, then most likely it is damaged. The reason for the failure of the driver IC can be overvoltage on the DC bus, for example, during sharp braking and insufficient bulk capacitor capacity.