On the old firmware #define EXT0_EXTRUDER_COOLER_PIN is set to 7 and if I'm not mistaken it should be wrong because the pin I use for the fan is 6, in fact even on start configuration string the coole

In configure.h i edited #define TEMP_GAIN 20 (from 0). It is Ok?

#define ZHOME_PRE_RAISE_DISTANCE 2

Regarding #define ENDSTOP_Z_BACK_ON_HOME 20 I correct it immediately as soon as I connect the printer.

Ok good luck. Make sure you have set #define ENDSTOP_Z_BACK_ON_HOME 20 or so so you are not directly at the end stops. With 0 at least one will stay there depending on the end stop offsets in eeprom.

#define SDSUPPORT 0 (dachte mann könne den SPI Bus für SD ausschalten oder entlasten..SD brauche ich nicht)

#define STEPPER_FREQUENCY 100000     // Maximum stepper frequency.

#define Z_PROBE_USE_MEDIAN 0/1

#define ZPROBE_ADDRESS &endstopZProbe

#define NUM_TOOLS 3

#define NUM_TOOLS 2

#define ZPROBE_ADDRESS &endstopZProbe

#undef ZPROBE_ADDRESS #define ZPROBE_ADDRESS &IOEndstopZMin

#define NUM_TOOLS 3

PS: What I did non mention: I have "#define LAZY_DUAL_X_AXIS 1" in the manual additions. Could it have to do with that?

#define ENDSTOP_PULLUP_Z_MIN false   <---change to true

#define Z_PROBE_PULLUP 0  <----- this should be 1 to enable internal pullup resistor,

#define CONFIGURATION_H

#define CONFIGURATION_H

#define FEATURE_Z_PROBE 0    <-------- set to 1