A little technology

Repair is a profession...

It's also a passion


The purpose of this short article is to show that...

Nikon Micro 105mm f/2.8 AFs G

in extremis

This is a high quality lens, both technically and optically.

Robust construction, but like all photographic equipment, it cannot withstand a nasty shock.

Externally, it appeared to be in good condition, but it had become completely unusable by a
depression on the side at the front.

Result, nothing worked anymore, manual and auto focus completely blocked,
in short, a good optic to become a paperweight.

These optics are a judicious mix of relatively classic mechanics (zoom type)
and 100% electronic management with the famous ultrasonic SWF motor and in addition a stabilizer.

Disassembly is extremely rigorous, long and even dangerous, because there are many welded layers and wires.

This must be done with at least an anti-static bracelet.

I spent, basically, two full days there, on the one hand dismantling, finding and solving “the problems”, partially reassembling for tests, etc., etc.

The focus ring had a nice marked shock, a slight haze and the front ring was even a little split.
The front is removed by lifting a plastic cover glued around the front.
It reveals a large number of black screws. Disassembly allows the headlamp to be removed.
Below, another set of chrome screws remove the front bushing.

At this point it is possible to remove the focus ring.
The shock was not recoverable, due to lack of space and, above all, very localized.
So I opted for internal grinding, reducing the thickness of the metal and finding a more logical shape.
But, that was only the first problem…

Disassembly of the barrel, part of the electronics and connectors is done from the rear.
Disassembly of the frame, the rear protection, the housing contactor, the rear barrel using 4 long screws on the outside,
(one of which is already a little massacred).
To fully access the interior of the optics, you must unscrew 3 Teflon slides on the side of the motor,
remove the mode selector block without forgetting to remove the cable previously disconnected from the electronic block,
3 screws including a large one which is hidden under the VR symbol.
We can then remove the central part of the barrel.

Then, you have to disconnect the cables, unsolder the wires, take out the SWF motor (the welds must be really flat, otherwise the motor will not come out), dismantle the distance display, the brushes (one of which had suffered badly), etc., etc.
The observation was that the rotating ring which drives the motor was blocked, in any case, the manual rotation
required too much force for an AFs lens.
It is held in place by two large screws, which secure two tiny ball bearings.
Removing them was not easy and for good reason… The internal barrel was distorted. One of the rotation locations
one bearing had become too narrow and the other had become wider than normal. Lost for lost,
I gradually straightened the internal washer (I keep the method confidential, you would call me crazy!!).
Finally, the bearings regained their functions, and upon reassembly, the motor drive ring
has regained its flexibility and normally drives the focusing mechanism.
Reassembly is of course the opposite of disassembly, welding the wires to the layers is very delicate,
no soldering iron too hot and of course a little flux.
The engine runs, tunes up, although it tends to slip a little.
Unsolvable problem without Nikon electronic SWF control equipment.
The point ring is a little firm, but usable. A saved optic, even if it is not totally perfect…
The ideal would have been to change a few parts with new ones, but hey… ??

It’s really not the type of optic that I prefer, long live good classic mechanics.

I decline all responsibility if you damage your toys !!! There are professionals to do this work !

Nothing is totally impossible