the problem might be the level sensor mounted inside the bracket where the basket rotator is. This sensor monitors the level of the basket and tells the hydraulics to move the lift and slave cylinders in such a way that it keeps the basket level while raising and lowering the boom.
check the wiring in the harness going to it and make sure there is no damage to the connections or the wires.
There is a test procedure but i need to know the complete model and serial number so i can get the right info from the tech literature.