After having replaced one esc that I burned because of a too hot soldering iron, APM arms but motor won't spin, except if I move the throttle stick up. When connected to MP, I have "system 1 is armed", but motors stay still. I can fly my copter, but I love this safety feature of APM 2 of seeing the motors spinning at min throttle. I changed MIN_THR_SPIN to different values, from 0 to 300, but it doesn't change. I also did the auto calibration of the esc, without success. What do you suggest? Am I missing something? Is it a way to reset the APM? I run on the mac version of mission planner, I didn't find the CLI. My PWM stay between 1100 to 1900 on all 4 axes.