18-200 AF-S DX AF Problem

[SteveGriffin]

Can anyone suggest what I might be doing wrong or has my lens died.

Using the 18-200 on my D70 - ver 2.0 firmware it won't auto focus.

I have tried changing the 'M/A - M', 'VR On - Off' and 'Normal - Active' switches but nothing.

I can manually focus and when the focus is OK the camera will take the shot but otherwise just errors R04.

My other lenses all work fine on the same body


Any hints??

[Oz_Beachside]

C-S-M AF mode switch?

Minimum distance to subject?

dirty CPU contacts?

[gstark]

Steve,

I don't know if this thread will help, but sounds very similar.

[SteveGriffin]

Tried the AF mode selector switch, cleaned the CPU contacts on the camera and lens (neither look damaged in any way).

When I half press the shutter button the lens makes a quiet click and 'unclicks' when the button is released

[gstark]

Steve,

Please refresh my memory on this aspect - does this lens have a focus limit switch (like the 80-400) ?

Does the clicking noise sound electronic or mechanical? Using some plastic tubing like a stethoscope, perhaps you can isolate the source of this noise?

Greg, how about on your lens?

[SteveGriffin]

No focus limit switch on this one.......

It sounds like a solenoid engaging and on closer listening it sounds like a motor spinning the whole time that the shutter button is pressed.

I have tried at a variety of focal lengths and lens/camera orientations. It doesn't have any rattles YET!

I am starting to think that the AF motor is disconnected from the knee bone

[Oz_Beachside]

It sounds like a solenoid engaging and on closer listening it sounds like a motor spinning the whole time that the shutter button is pressed.

I have had three VR lens, and all emitted a click sound when the VR was on, at shutter half press. and again when I released the half press (or AF-ON button equivalent).

[SteveGriffin]

Correct,
with VR off the click and whir are no more - now it is really dead

[gstark]

Steve,

Grab another body and see what happens with the lens mounted there.

But it's sounding serious issue in the lens.

[SteveGriffin]

Grab another body and see what happens with the lens mounted there

I grabbed the wife but she won't hold still for me long enough to attach the lens.......

There are no other bodies about.......


What should I do next..............

[gstark]

What should I do next..............

I was thinking more along the lines of perhaps giving Simon or Trevor a call.

[SteveGriffin]

Oh yes I did that too

I am off to Vanuatu in the morning so I guess it will be off to Andersen's for a warranty repair when I return

[smac]

Steve,

On the body of the D70 there is a small pin that drives the autofocus. Sometimes this pin gets stuck and doesn' connect with the lens. Here's what to do.

Take the lens off the body look for the hole where the pin is (on my D200 it is at 7 o'clock when you look at the front of the camer). Get a pen or someting similar that will go into the hole, push the pin and it will spring back out (hopefully).

The noise you hear is the pin spinning but not connecting with the drive screw on the lens


Stuart

[SteveGriffin]

No that is not it either.....
Sadly

[Mr Darcy]

Missed this earlier due to blindness.
Sounds like exactly the same fault as mine. Possibly an emerging issue with the lens.
I will be visiting Uncle Ted in the morning. Will keep you posted.

I just got a 105Micro in the post (Thanks Poon), so can confirm mine is the lens not the camera,

For reference:
AF does not work (Snap)
Lens goes Clunk on half press if VR is on. Silent if VR off (Snap)
Focus Assist (green light in viewfinder) works (snap)
If lens happens to be at correct focus, camera will fire
M/A override works OK (Snap)
Another lens works OK on camera (Snap)
Resistant to new battery, cleaning contacts, firmware reset etc.
Don't have another body, so can't confirm it is not a compatibility issue., but will check at Ted's before I send it off. (The new D200 pricing is mighty tempting!) BTW Focus drive pin on camera is not used on this lens, so not relevant

[Mr Darcy]

Ted's tried my lens on another camera. They confirmed the AF is dead. ETA 4 weeks

At least it's under warranty.

[Mr Darcy]

My Lens is back

The official report is

"Dismantled unit Replaced SWM unit and reassembled, Cleaned, Checked Tested"

It would appear the focussing motor was faulty.

I had a quick play. The lens seems slower to focus than before, but since I didn't exactly time it before it broke, I can't be sure.

A VERY quick test shot:

[jberth1]

wow - I've never noticed mine vignetting like that - I'll have to test mine now. Did yours do that before ?

Cheers

Justin

[Mr Darcy]

Yes it did.
But I only notice it occasionally.
The background must be plain of course, and in this case f=5.6 l=200mm . One day I'll do a series of shots and work out when it happens. I expect it is related to f number, and of course, it IS a DX lens so I would not expect the edges to be always perfect.

This was taken at 1/25 sec 200mm hand held I'm not going to complain about a little vignetting in the corners.

[Mr Darcy]

Here's a sample before repair.
Also f5.6 200mm