Case 445CT - arm won't move

Well, I was using my grapple bucket to move some cut trees and all of a sudden I lost the ability to raise/lower my bucket. I can tilt/curl No problem, but pushing on left arm left/right....nothing. It moves track back/forward No problem.
Any thoughts on where to start diagnosing? Could it be a fuse, actuator...?
Any help would be greatly appreciated. Thanks in advance
Drew

Case 445CT - arm won't move