When I press "Home All," instead of turning, the x-axis motor just makes a sort of humming noise and doesn't move the hot end at all. I've tried to tighten the pulley only to find that the actual center rod thing in the motor isn't turning either, so I don't think it's because of any slack or a loose pulley. I've also detached and reattached the connector to no avail. The other two axes home fine, and it was working fine before, too, before suddenly stopping. Does anyone know what the issue might be?