I tried 2 flight controllers, 3 motors same problem.
I am using firmware 4.5.7. First flight controller was a SpeedBee F405 mini stack. It was flying ok for a couple of flights. I had an analog VTX and camera onboard. I decided to fly FPV. Could not get the VTX to power on and off. VTX is a HolyBro Atlat micro HV. Cannot change VTX power either. So I flew with the VTX set at 200 mW. Lost video three times leading to a crash each time. Then motor three started to stutter when I arm. Trouble shoot involving testing the speed controller, changed motors. No luck. Motor tests in Mission Planner and QGround Controller had same issue. So I bought more motors and another speed controller.
In the meantime I have a brand new MicoAir 743 AIO. Replaced the flight controller to the MicoAir. Same issue. Pulled the flight controller and installed into another quad with a different set of motors. Same problem with motor 3 (front left).
So I flashed iNAV 8.0.1 on the flight controller. All the motors are working just fine.
So what can I do to solve this issue with Ardupilot? Resources on Ardupilot online is thin. Not a ver popular software so I am at wits end.
Thank you in advance for any help.
Oh I am using 1303 5,000 kV motors and 1303 5,500 kV motors spinning 3" to 4" props. I tried 2 cells and 3 cells. The 1303 5,000 kV setup was flying for a while on 3" prop and 3 cells.