My prusa i3 v2 assembled and everything works besides the z axis. I can home z just fine and moving down is fine, but moving up won't begin until after about 5-10 tries of pressing the up button on the manual control in repetier, along with hearing grinding and humming noises. Then the z will move up as if there were no problems but once it has been homed or has moved down, moving up will struggle once again. Have contacted reprap support multiple times and only seem to hear back when they feel like responding.
