Quote Originally Posted by Roxy View Post
Specifically: Check and make sure

#define PROBE_SERVO_DEACTIVATION_DELAY 500

is defined and has a reasonable value in it (500 to 1500 should be OK)
And it's worth checking that the servo actually shuts down. (I.e. you can easily move the arm by hand.) A few servos do weird things when the pulse train goes outside of its expected window.