One of the sensors is probably failing.
Probably the distance sensor.(LDS)
When the unit is standing up, there is a cover box on the shaft.
One of the sensors is there and is usually the one that dies due to excessive side movement of the shaft which scrapes the lens on the unit or it could be dirty or full of oil, all these things will cause failures.
Always have spares on hand because they do fail.
Does it go through the pindeck, begin reversing and stop?
Might have to do with a lino micro switch but my bet is a sensor.
There is a place in the MGR menu where you can bypass it. Assuming a 3 speed?
The sensors have a red LED that lights when the beam isn't blocked so you can tell if it's working if you rotate the shaft with the unit powered up. (blinks)
Hope that gets you going.
Keep us posted
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