Hi all, My D3 has been to Nikon USA twice now with an autofocus problem. Occasionally the autofocus will just lock up and refuse to function. It's not a low contrast target problem. If the lockup occurs I can swing the camera to any target and it still refuses to autofocus. Then, for no apparent reason, autofocus will resume.
After Nikon techs were unable to replicate the problem twice in a row, after a charge of $420 plus shipping and tax for the repair that never happened, after shipping the camera to them twice for a total charge of about $110, I decided to do a bunch more testing to see if I could find a way to get autofocus to reliably lock up.
What I found was that with my zoom lenses, if my hand was on the zoom ring the lockup would happen randomly, but if I took my hand off the lens and moved it to the body, autofocus would reliably unlock. Then I found that if I held the camera with my left hand in contact with both the lens and the body (as shown in the attached pic), the camera simply would refuse to autofocus. That would happen with all my lenses, even my primes.
I've told Nikon about this, hoping to hear that they've seen this problem before and know how to deal with it. In my own estimation it looks like a grounding problem.So far, no answer. I'm almost reluctant to pay to ship the body back a third time since Nikon seems unable to deal with the problem.