shortcircuit48:
Spent a bit of time today to see if I could narrow down the problem. When using the A4988 driver there is very little torque from the steppers and they are easily stopped. I rigged up a couple of L298N drivers and ran a simple sketch and it is like night and day as impossible to stop the stepper. Should there be any reason the torque is so low with the A4988? They work but could they be faulty? I have been very careful today to ensure all power is removed before making adjustment.
You probably need to define the initial conditions linked to the things you did above. Eg... which arduino you used..... new one or the old/original one. Also.... what problem are you trying to narrow down? The problem with the old arduino? Or something else?