I’ve looked through other posts with the same issue but have not found a solution that works. I have a stock setup BlueROV2 Heavy that uses a stock pixhawk and Blue ESCs. A couple of thrusters spin slowly in a couple of second bursts as soon as I arm in manual mode. Right now, that is thrusters 2 & 3 but that doesn’t seem to be consistent. I have also seen thrusters 1 & 3 spin when armed. I have run the calibration of my Logitech F310 controller and correctly configured the directions of my thrusters. Not sure it matters but I am running BlueOS firmware on the latest version. I’m using QGC V4.1.4.
The main potential sources for that which I can think of are:
Physical joystick deadband is larger than calibrated for, so the motors are receiving a non-neutral signal without you pushing the joystick
should be detectable by seeing non-neutral signals (not 1500µs pulse-duration) for the affected motors in the SERVO_OUTPUT_RAW message in QGC’s MAVLink Inspector while the relevant joystick is released
should be fixable doing deadband calibration in QGC
Thanks @EliotBR. I did figure out the issue today. It was just a bad controller. I bought a new Logitech controller and it fixed the issue without any additional modification. I do appreciate your detailed response and I think this will certainly help someone else with the same problem. Thanks!