@darwinFPV
did the supplied answer help you?
i have the same issue, but with a geeetech g2s pro.
i've had is slightly diassambled for a while. as i broke a hot end. did some bearings mods and different hot ends and started using the newest repetier ands since then it won't move down. both up and down button on the z axis let it move up. until 1 (not all three) hits the stop end.
i tried checking the h119 but all stop ends for the x,y,z (max) axis work fine. and i don't seem to have a difference..
but while i was typing this i realised that maybe the g2s version of h would be z-min. so although i have no use for it. i hooked it up and voila. problem fixed.
so thank you repetier for this answer!!