Due a low 3V battery and power off situation all the saved data on the Tac20 CPU board was lost, so I downloaded the job files to the board via hyperterminal, including the job configuation. The is only lower and top floor at the job. IMS screen shows position=2, Floor Ref=999999999, Pos Count= 731564543. A new hoist learn was necessary, but when starting the learn, the hoist moves to the lower floor, IMS Position=0, hoist goes down 3 inches below lower floor, stops and then moves up, but instead to move to the top floor to finish the learning, it stops right there at lower floor level, and fails the learning. For a brief moment (half a second) Pos Count becomes 10024 and return to 731564543. Fails the learning and gives me SELECTOR error (even on IMS hoist learning screen), errors 1031 and 1056. I already checked and measured positions of magnets and selector boards, connectors, cables. Interesting that IMS shows everywhere the hoist is at the floor #2, not #1. IMS inputs shows correctly BPP at lower level and BP1 at top floor so it is not this. Still it thinks it is at top floor (2) and this (I think) is the reason why it stops at lower level and not complete the learning. Any help will be appreciated.