Well, I know they were at least skeptical. When my lens went all fraschtuka at the Air Force Museum, and I said that I wasn’t sending it back to the factory again because it wasn’t forth another investment, I said I would eventually get around to taking it apart to see how it ticks, if nothing else. Well, last weekend I finally got into it and took it apart. At least, as far as I could. Seems I needed a few tools. Who would have guessed?
Seems the regular eye glass repair type tools won’t work. And I found out that the range of screwdrivers that run below the #1,2,&3 sizes are referred to in “0’s”. So I got me some. I probably spent about 1 1/2 hrs. disassembling and figuring out how the thing goes together and how it functions. The hardest part of the whole deal was working with the little itty bitty wiring harnesses and the circuit board. They have a number of different types of connections.
Anyway, I got the lens down to this point.
This is where I discovered the problem. Seems one of the screws which holds a plastic tracking wheel in place, had backed out. It was obviously a SNAFU from the previous repair where they had neglected to properly glue the screw back in place when they repaired it.
That’s it! That overexposed little round thing. I tightened it and then came the real adventure. To reassemble this bad boy.
It seems I took some short cuts when disassembling and had to further disassembly to reassemble it.
The first obstacle was the zoom ring. It was in the way and it took awhile but I finally solved the issue. Detaching the zoom ring. See that chrome piece.
Thats a retaining/mounting screw that connects the ring to the mechanism and it is removed by peeling back the rubber around the ring.
Gotta go eat dinner. Stay tuned for part two.
Re engaging all the parts at this point took some study, as the focus ring and zoom ring operating mechanisms all go together at this juncture. It was almost impossible to photograph that and have it make any sense at all. After that was completed the task of attaching all the wiring harnesses to the circuit board would be next. I have to say that I was a bit unsure of whether or not I was going to damage something here.
Here’s a shot with the drive motor, focus ring, and aperture assembly mounted on the lens with all the wiring harnesses hanging loose.
This is with the circuit board attached and wires in place.
You can see here how all the wires connect to the board. There are actually several different kinds of locking/securing mechanisms to hold everything in place. Quite ingenious.
There’s no real way to show it but the final connections were a major pain. In this last photo, you will see the contact assembly (all the little round shiny things) is hanging loose. It had to be disengaged from the mounting ring, attached to the board and then fished back into the ring, this while attempting to make sure that the aperture actuation prong, which is attached to the mounting ring, was installed in the correct position and then reinstalling the extremely tiny screws that hold it all together.
AND…No parts left over.
And….the damn thing actually works.