Lens not auto focusing

[briand7878]

Im about to throw a fit!!! I have a Nikon D90 and just bought a lightly used nikon 70-200 thats 2 years old. For some reason it has a mind of its own on auto focusing. Sometimes it will actually search for a focus, beep and take a pic, and sometimes it wont budge. Ive tried turning it off and on, removing the lens, removing the battery and sd card. Ill take pics for a minute and then boom. No more auto focus. Ill fumble with it for 20 minutes and then boom, we have focus. Ive tried cleaning the little focus bumps on the lens itself but it did not help. The only thing i can think of is that it is not making good contact. If anyone has ideas I would gladly listen.

 

[Derrel]

It sounds like a contact issue. The very earliest production examples of the 70-200 VR had a contact grounding issue that Nikon was able to correct under warranty. I was told that the screws that fasten the mount to the lens barrel werw changed from the long-time material to a new alloy,and that the lens CPU was affixed to the screws as a ground, but that the new alloy did not provide a good enough and reliable ground, so the contact to contact interface between the lens's CPU and the body contacts was not reliable. The solution, I was told, was to replace the alloy screws with the older screw Nikon has used for 30+ years.

A really good, deoxidizing contact cleaner might help. Also, check the tightness of all the screws that hold the lens mount onto the lens barrel,to make sure the screws are tightened all the way. If none of those things work, I would send the lens in; it is possible that the lens could be older than you think it is.

 

[thebeatles]

^^^Man, how do you know this stuff?^^^

 

[PhotoXopher]

I'm starting to wonder if the problems I had weren't the lens but the camera (D90). I had the same issues with a Tamron 17-50 and Nikkor 80-200.

 

[briand7878]

Wow that is good info.....This is the only lens that is doing it to me. I hope its something easy, I have a trip to hawaii planned in 2 weeks and want to take this lens.

 

[ZEPHYR]

Sounds like a bunk lens, I dropped a lens before and the lens was never the same, it would do the same thing that your lens is doing, or not doing.
I tossed it, there was no hope for it. Repair was too costly so I got another lens.:thumbup:

 

[KmH]

Wow that is good info.....This is the only lens that is doing it to me. I hope its something easy, I have a trip to hawaii planned in 2 weeks and want to take this lens.

Since the lens is no longer in warranty don't send it to Nikon USA service, because you won't get it back in time for your trip.

You will find a list of Nikon approved independent repair stations here: Nikon Authorized Repair List