mamba max won't calibrate!

[Sammus]

They test them all. Maybe its a problem at your end. Maybe some silly suggestions but:

1) Do you have the motor plugged in? You wont hear any of the tones unless the motor is plugged in.

2) Are you using a Spektrum radio by any chance? Spektrum take a bit longer for the Tx/Rx to bind to each other after power up, so sometimes the esc wont read the throttle input before it arms. You can change the startup delay with castle link. Some other radios I think exhibit this behaviour, not sure which ones though.