Finished assembly, enabled homing and tried to home, instantly get a limit switch hit error message. Realized the z carriage was all the way up. Powered down, lowered the spindle off the z limit switch, still getting the same error. When looking at the board, the x and y limits only light up when depressed. The z is lit all the time on the board until I unplug it. Tried to plug the z in to where y should be, constantly lit. Likewise, plugged the y into where the z was, only lit when depressed. Is it a bad limit switch? Any way to try to reset it? Thanks.