TroubleSooting Suggestion
Before going too much further; I have a troublesooting suggestion:
If you have a break out board or some other means of hooking the signal wires from your parellel port to your driver board, try the following:
Assuming the Y axis has the problem and the X & Z axes are both O.K.
Swap the Step & Direction signal wires that are comming from your parallel port to your Y axis with one of the other axes.
In other words, the parallel port signals that are presently driving the X & Z axes are working fine, so use one of these to temporarily drive the Y axis.
If the Y axis starts working fine, and the problem moves to the axis you swapped with, then I would be suspicious of the parallel port.
If however the problem continues to be on the Y axis, this procedure pretty much rules out the parallel port as the problem.
Can you do this?
Patrick;
The Sober Pollock