I have mach3 running for 3 years with no problems - until now:
when I want to move the Y axis (left or right) with the keybord (arrow up/down) it moves randomly in a direction.
The same when I use the home button on the mach screen it moves randomly in a direction mostly the wrong one.
when I press the same keybord arrow twice (or more) the Y axis moves randomly
I checked the hardware, limiting switches, cables, connectors, even swapped the geco motor drives - no luck
Any idea how to check if mach3 is causing it
Hans