@900turbo I just noticed in your config.g that your X and Y axis endstops are set as minimum end endstops, but your homing moves move the Y axis to the maximum end:
config.g endstops:
; Endstops
M574 X1 S1 P"121.io2.in" ; configure switch-type (e.g. microswitch) endstop for low end on X via pin 121.io2.in
M574 Y1 S1 P"io0.in" ; configure switch-type (e.g. microswitch) endstop for high end on Y via pin io0.in
In the above, M574 X1 and Y1 define the endstop as being at the low end, ie where the axis is 0.
homeall.g Y axis homing moves:
G1 H2 Z5 F6000 ; lift Z relative to current position
G1 H1 X-705 Y705 F1800 ; move quickly to X or Y endstop and stop there (first pass)
G1 H1 X-705 ; home X axis
G1 H1 Y705 ; home Y axis
G1 X5 Y-5 F6000 ; go back a few mm
G1 H1 X-705 F360 ; move slowly to X axis endstop once more (second pass)
G1 H1 Y705 ; then move slowly to Y axis endstop
In the above, the X axis moves towards the low end with X-705, but the Y moves towards the high end, with Y705. Your Y endstop should be at the high end, eg M574 Y1 S1 P"io0.in".
Which is correct? Check that the motors move in the correct direction first. Which is the correct direction for motor movement? RepRapFirmware expects the axes to move using a right-handed coordinate system, because that's what CAD and slicing software uses. Looking from the front of the machine, +X to the right, - X to the left, +Y to the back, -Y to the front. This puts 0,0 where the nozzle/tool is over the the front left corner of the bed. This can be rotated 180°, so that 0,0 is at the back right corner, but it should not be at the back left or front right. If it is, change motor directions, and then set where the endstop is.
Getting the direction correct for a CoreXY is slightly more complicated, because it may mean swapping the motor connections. However, there is a guide for that here: https://docs.duet3d.com/User_manual/Machine_configuration/Configuration_coreXY#testing-motor-movement
Ian
