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Teleconverter AF malfunction


I have two D100 cameras, the 300mm EDAF-S lens, and the TC14E II and TC20E II AF teleconverters.

The 300mm AF-S lense will sometimes not autofocus when either teleconverter is used. Mounting the lens directly on the camera works, however.

I've tried all combinations of the two cameras, two teleconverters, and the 300mm lens to try to isolate the problem. Cleaning all the electrical contacts appears to fix the problem sometimes, but not always.

Anyhone else have this type of problem?
Erik, I am the man you want to see!!!!!!! I have a freakin' wealth of infromation on this disturbing problem and believe me, there is NOTHING on the web about it.
I had the same problem as you with 300mm afs on f100. This is a semi-acknowledged, yet not widespread problem. I think the best thing to do is for me to post something I posted from another forum:

Scott Linstead , sep 06, 2005; 10:49 p.m.
Ì've posted this before, but I gave too many details.
So...I use an f80 and 300mm afs and tc-14e for 8 months, no problems.

I buy an f100, the problem starts. sometimes when I take the camera out of the bag with the 300 and tc on, it behaves like the lens is in M mode i.e. it won't autofocus. To fix the problem, I twist lightly on the lens relative to the body...it goes back to normal.

I had this problem on 3 f100s (I brought the body back twice) SO ITS THE LENS, RIGHT?

BUT WAIT, why does this not happen on the f80?


BUT WAIT, it happenned once WITHOUT the TELE, although it happens MORE OFTEN with the tele.


This would mean that the f80 and f100 use the contacts in DIFFERENT ways to do the SAME THING...somehow, it seems that Nikon would really be complicating things for themselves if this was true.

In any case, nikon montreal wants EVERYTHING to pass back and forth from one tech to another between their "regular" tasks -- time is measured in weeks. Also, they aren't as technically equipped as nikon toronto, so it may have to be SHIPPED there for awhile if they can't get the problem worked out in Montreal -- time is measured in months. Try to put yourself in my place, is this where you'd like your brand new $4000 kit to be?

Scott Linstead , sep 27, 2005; 09:02 p.m.
I feel it is my responsibility to post the results of my little service adventure, considering that its a lot easier to write when you have to send your gear away, but when it comes back repaired and in working order, the last thing you want to do is jump on the net and start typing.
So my experience with Nikon Canada has been a good one. "Ty", the director of service was an agreeable and knowledgeable fellow, always willing to deal with my telephone inquiries in a pleasant manner.

You can check out the details of my problem in a previous post, but long story short: the AF cut out occasionally with and without my tc- 14e attached to my f100(brand new) and 300mm afs f4.

As I was informed by Nikon, there exists an issue with both the lens and the tele, whereby an additional ground must be installed on the integrated circuit of both items. This improves the AF interface with pro bodies, i.e. D2x, f100, F5 etc, that is somehow more sensitive to poor contact connections. Apparently this has turned up with D2xs already in combination with this lens-tele combo, so take heed all you yuppies(just kidding).

I guess tha turnaround time is of interest. I dropped the camera off at Nikon Montreal on Sep. 8th and I picked it up today (Sep. 27th)

On the bill (it was all under warranty) the f100 got "automatic tune- up" the tc-14e and 300 both got, "repair integrated circuit". All 3 items got the old CLA.

So thats the story...seems like a happy ending, (knock on wood). Thanks to all who contributed and commented during my darkest hour (LOL)


Thanks for your prompt email!

I've only had the 300 afs malfunction once when it was connected directly to the camera. I cleaned all the contacts and that seemed to "fix" it. But then the problems with the teleconverters started.

I've tried twisting the lens/teleconverter combination as you describe below, but this has never really "fixed" the problem for more than a [very] brief period of time. Sometimes removing and remounting the lens/teleconverter has "fixed" it, and I shot for the rest of the day (but without removing the lens/tele).

I assume from your second attached post that the problem has totally gone away?

Question...all my equipment is out of warranty (i.e., older than 1 year)...is Nikon going to try to charge me for the repair to the lens and teleconverter? I'm off the my local Nikon Dealer/camera store tomorrow to send in my equipment...I'll bring this email along for them to read.

Thanks again...looks like there is a light at the end of the tunnel...

Erik Breden
Elgin, TX

I'm not sure if they're going to try and charge you or not, but if its any help I can give you the repair codes from my bill. To paraphrase the director of service in Canada, after the repairs were done: "Most of the ground issues on the lens were caught in the factory, I'm surprised yours needed to be fixed." He went on to imply that the tele repair was expected from his point of view, so basically the its the same issue on both the lens and tele and it seems to me that they know about the problem.

In Canada, lens warranties for nikkors are 5 years, including teleconverters. Nikon has been known to fix "known" problems out of warranty.
If I can be of any help, let me know.

Its a great lens and tele combo, especially for birds in flight. If you're interested, check out my owls in flight at www.scottyphotography.com

Turns out both teleconverters are still under warranty along with the 300mm lens. I dropped them off at my camera store today to be sent to Nikon for repair...I'll let you know what happens.

Thanks again for the info...

Hello from Italy, Erik and Scott!
Don't forget, Teleconverters step down Light-level(Value) which reachs, inside the Camera-body, both the Focal-Plane and the AF Sensor; this, beeing inside the Camera-body, not on the Objectiv.
Besides, the 300mm Telephoto starts stepping down light at f/4 already, which come down like at f/5,6 when the TC14E II is added; and at f/8 with the TC20E II.
Any AF Circuit needs a light-level enough, to work properly; as well as it needs a certain contrast among the details composing the image: the magnification as more You get by using Teleconverters, reduces the "area" of the Subject furthermore.
It is hard, AF-focusing in the darkness and against a bit of white wall.
So, I do not think problem as due to electrical contacts; I don't do, since Erik tried already such more pieces, carefully!!!
It can not be taken from Your description, under what LV and Subjects You tried on; maybe, You reached the working-limits of the Lens+T.converter, simply.
As soon as the issue appears again, You should try, whitout removing and remounting anything, to go under stronger light, i.e.:LV=14 (outside house with sun) shooting at something else.
When using Digital Cameras, LCD Monitor does not let You think sometimes as low Light-Value is; as LCD takes &lified signal!
For the records:
D100 mounts the same Multi CAM900 AF-module like F80 does;
while F100 has CAM1300 AF-module.
Results may be as different, then.

Thanks for your input. Low light levels reaching the AF sensor due to the use of a teleconverter is definitely not the problem in this case.

I have had the malfunction occur on a bright sunny day at the beach, a very "light intensive" environment to say the least. One minute the equipment is working fine, then it stops working.

Erik Breden
Also a too intense light may make AF Sensor as unable. From D100 Specifications:
"Autofocus Detection range: EV -1 to EV 19".
Which become EV +5 to EV +25 through 300/4 w/2x T.converter.
But I not longer think this as the reason, now.

If We wish still research on electrical contacts, then inside the Lens there are micro-slides running on strips; moving according with Lens' movements. Also, there is grease inside the Lens.
I opened several Nikon AF Lenses already (never a 300mm, yet!) to clean glasses from dust and a few but very black dots, which are bits of grease going around the Lens. Sometimes, I found some ones near those micro electrical contacts, too.

Is Your 300mm clean at all inside, or shows some of those black points?
They might even insulate contancts; I think it as a remote possibility, though. Also, a micro-slide might have been damaged when the Lens was assembled in factory.

Also, don't forget Digital Cameras take many energy from batteries in a while so, they quickly result as low on the next shoot, leaving some circuit on "tilt"; but after a time of "rest", batteries refresh again.
You might try, as soon as the problem appears, turning off the Camera at all (as a "reset") and replacing them with fresh batteries.
Just to know whether that may be a co-cause to be isolated.

Thanks for the fine talk,

Thanks again for your additional input.

I think both Scott and I have tried all these remedies (especially cleaning contacts and replacing batteries). The problem didn't get "fixed" until Scott sent his teleconverters and lens in for repair (as described above).

Scott...I assume you haven't had this problem since the lenses were "repaired"?

Erik Breden

You assume right, not a hint of the problem after the repair and I use the equipment quite regularly. Thankfully, the repair is a specific one, according to Nikon, and not just a shot in the dark (no pun intended
). They seem to have a contingency to deal with it. It just isn't as well known problem as say the 'BGLOD' syndrome with the D70.

Another bit of useful information: I just bought a tc-17e which is newer than the tc-14e and tc-20e. It does not seem to affected by the problem and works fine with my gear.

Anton, thanks for your polite and thoughtful contribution...This forum is not as active as photo.net, for ex&le, but the people here are considerably more agreeable.