This problem started after the rod end line between the slide cylinder and sync cylinder blew. Probably when it was retracted. At our next stop it was noticed and now the line has been replaced but I'm not sure how to safely get it moving. I've manually released both cylinders and tried to move it by hand but no luck.
After hydraulic hose replacement and fluid fill of reservoir and reading the "manually retract" and "synch cylinder balancing" documentation I decided to just try the retract switch for the slide and it worked. PS I had tried the manual procedure of opening the two solenoids for the slide and wenching with no luck.