It runs in reverse from MACH or from the manual panel? If the manual panel you can swap spindle wires, but I doubt they were ever removed, right? If it is reverse ONLY in MACH, there is a setting in Mach you need to change.
Machine not changing direction is common. First, though, NEVER use the x10 setting. It is really buggy (just the way Phil wanted it - we tried to tell him how bad an idea it was to have it the way he wanted it) and you WILL lose steps if you use it. X1 and X100 are both pretty bullet proof. When you reverse directions, make sure you pause at a stop in between directions. If you go fast clockwise and then immediately reverse to fast counterclockwise, it will still think you are going clockwise. If you pause a fraction of a second before you turn the other direction, you should be good to go.
Limit sensor failure is common. Look for water-tight versions or make your own (there is a long thread on here for making sensors). The Mikini sourced ones fry pretty easy.
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