'Home Z' differs from 'Auto Home'

Hi everbody,

I've build my own printer using Ramps 1.4, a smart controller and the marlin 1.1.8 firmware. It almost works, but I am facing one 'last' strange problem:

Home Z:
After hitting the z endstop the printer probes for a second time with slower speed. After hitting the endstop, the nozzle is in perfect distance to the bed (as adjusted).

Auto Home:
After hitting the z endstop the nozzles drives ~1mm above the bed and stays there as 0 position. There is no slower speed probing.

Since Auto Home is called from the .gcode file; every print starts at this 1mm position -- resulting in a failed print.

I am struggeling with this problems for some days now. Does somebody have any idea? Do you need more detail?

Attached you can find the Configuration.h and Configuration_adv.h

Best.

I had this problem when I incorrectly set the M206 command in the slicer.

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Proud owner and maker of build from scratch FDM 3D printer [forums.reprap.org]

Thanks for your reply.

Writing and reading with M500 and M501 works in software but has not effect on the hardware.

However, I can reproduce the following behaviour:
Auto Home -> allways strange Z offset

Home Z -> no strange Z offset
Home Z -> strange Z offset
Home Z -> no strange Z offset
and so on (toggling)

Any ideas?