I had the same problem. I thought I knew how the coils were supposed to be connected to the drivers but apparently I didn't. Be sure that you have two wires that read a resistance together on the pins that say 1A and 1B or 2 A and 2B. I thought that one coil was supposed to attach to both of the B's and the other to both A's but this is wrong. When I had it connected this way the motors produced a lot vibration and didn't rotate.
Hope this helps.
Hope this helps.