No, all voltages seem fine. I've powered Masso off and back on and it's now working fine. Annoying because it seems do this randomly.
UPDATE: I think I figured it out. If you have a homing alarm and your machine coordinates are outside the travel min/max (which often times they are because Masso seems to throw it a random number every time), the axis will only travel in one direction. I think it's the direction in which it thinks the home sensor is. Solution is go into F1 setup, give the travel direction in which you want it to move and give it a ridiculous number like 100,000 then try again.