#define Z_PROBE_Z_OFFSET 0

#define ENDSTOP_PULLUP_X_MIN false

#define Z_PROBE_START_SCRIPT ""

#define HEATED_BED_DECOUPLE_TEST_PERIOD 300000

First, verify that your probe is working with a G31. Does it toggle correctly? If you have a mechanical normally closed probe like mine, then #define Z_PROBE_PULLUP needs to be set to 1 before G31 wil

First, verify that your probe is working with a G31. Does it toggle correctly? If you have a mechanical normally closed probe like mine, then #define Z_PROBE_PULLUP needs to be set to 1 before G31 wil

#define FEATURE_Z_PROBE 1

in Configuration.h #define Z_PROBE_PULLUP is set to 0 by default, which is disabled. I switched it to 1 and my state now toggles correctly with M119. 

#define EXT0_ADVANCE_K 0

Ok, problem solved, had to increase #define DECOUPLING_TEST_MAX_HOLD_VARIANCE 20  to 40 to maintain heat balance on heated bed, also made deflector for end of fan cowling to deflect airstream away fro

Is #define ENDSTOP_Z_BACK_MOVE 2 set high enough to cause all switches to untrigger? That's the only thing I guess could cause homing fail i z length was set correctly. Also set floor safety margin to

#define DECOUPLING_TEST_MAX_HOLD_VARIANCE 20

#define FAN_BOARD_PIN -9  // was -1 (pins.h says Fan is on pin 9)

#define ENDSTOP_X_BACK_MOVE 1

#define ENDSTOP_X_BACK_ON_HOME 4

#define Z_PROBE_START_SCRIPT "M340 P0 S550\nG4 P1000\nM340 P0 S0"

#define MOTHERBOARD 402

#define Z_PROBE_Z_OFFSET 0

That could be tricky, since min endstop is meant to be at z=0. There is a variable #define ENDSTOP_Z_BACK_ON_HOME 0

#define SDCARDDETECT 49