Unable to manual focus on A1/ 200mm-600mm

[Rajiv Roy]

Hi All

For some reason, my ability to do manual focus on 200mm-600mm A1 has stopped. 

a) I have cleaned the contacts between the lens and camera. 

b) I have made sure that the MF switch on Lens is set.

c) I have made sure that the dial on the A1 is set to MF. 

d) I have upgraded both the camera and lens to the latest firmware. 

e) I have taken off the lens and put it on a second A1 body, still the same issue. 

f) I can take a 100mm-300mm lens and get the MF to work.

Any suggestions?