Nikon AF-S 400mm f2.8D ED IF II. Autofocus malfunction

[John G]

Hello
        I have had the pleasure today of travelling to Brighton as a extension to my daily London commute.         
        The purpose of the visit to Brighton was to view a Nikon 400mm f2.8D ED IF II.
        The model has a one owner history, used mainly for photographing field sports, with Rugby being the most photographed.
        The lens in 70% of new condition visually, but has a worn bayonet mount ring, this was declared.
        The lens is said to have worked fine on a D4s on the past weekend.
         When mounted on my D800E, the lens registered as I could use the command dial to scroll through the aperture settings.
         It would not AF, the body is set up using back button focus. The lever on the body to toggle between M + AF was set to AF.
         The camera body and Lens contacts were gently wiped clean with a dry cloth, there was not a cleaning solution available.
         On returning home I put a 50mm AF lens on the body and it has AF. 
         Any thoughts on how the malfunction could happen would be much appreciated.
         
         The vendor has made a offer to take the Lens to a Professional repair centre in the Vauxhall area of London, and when picking it up
         arrange a meeting at the repair service premises, to do a final pre sale check.
         I think this offer is a fair offer and hope it is maintained, the offer should leave a good feeling of assurance as to the lenses functionality.
 

 

[Bjørn Rørslett]

A worn lens mount is never a good sign and in particular the long lenses are prone to show such wear. However, the newer generations of long Nikkors are equipped with steel inserts that should reduce these problems. Is this steel insert worn, then there is a serious problem with the lens or its manner of operation.

Bad AF might be caused by damage to the contact block or signal cable inside the lens, both of which can result from impact damage (or wear to the the mount).

[John G]

Thank you Bjorn
                       

[Peter Connan]

I have a 300mm f4 that didn't AF on my 1.4 converter.

Nikon wanted all three items to diagnose the problem. Since I seldom use the lens, and my three cameras are of vastly different capabilities, I did not want to hand my camera in for an extended period.

However, a while ago my D750's shutter failed, and so it had to go in for repair anyway, so I handed in the 300 and converter as well.

When I got it back, I tested it in the shop and it worked fine. The next time I wanted to use it, it did not AF again. This time, it doesn't even work straight on the camera. It now only seems to work on the D100.

All I am saying is, even with that check, there is no guarantee it will work on your camera.

[John G]

Thank you Peter

After Bjorns explanation, I have decided to look for another lens.