Well, that proves its not Mach then.
OK, so we need to know why pin 3 doesnt work ( Im assuming the STEP pin is pin 3? )
Well ignore the DIR pin as if it was bad the motor would still move, just in the wrong direction.
So search for any signal you may have turned in in other motors, or outputs that is set to pin3.
Its about the only thing that can stop you. The pin will not be set to step unless no other pin uses it.
Pin3 is a bit in the 8 bit area of pins 2-9 , so theres nothing particularly special about it, so I cant see
anything other than 2 possibilites, the Y axis isnt working or the pin 3 signal is getting overwritten by an output
or other motor..
Any chance its that?
Art