I now owned a lens lens that had a stuck zoom and no response from the focus motor. I paid too much. If I have to buy a zoom barrel and a focus motor to fix this I will be paying the same as I would for a working lens.
The bright side is that this lens appears otherwise to be in excellent shape. The optics are clear and have no blemishes and the body is perfect. There is a little internal dust but that will be taken care of when I have it apart.
The dis assembly begins with the removal of the rubber zoom ring, under the ring there is a rectangular plastic cover you need to peel this off.
Beside the zoom brush you see a brass bushing with a black screw inside it. There are 3 off these and they will come out later.
Using a 00 size Philips screwdriver remove the 2 small screws holding the contact strip to the mounting ring.
Then a 0 size to remove the 4 screws holding the mounting ring to the lens body. The center plastic spacer needs to come free before you can release the ring from the contact strip. I lift the mounting ring carefully and slip a finger underneath and push the plastic ring out.
There are 6 ribbons that need to be removed to take off the circuit board. Starting at 12 o'clock and going clockwise. The first has two locking tabs at the edges. pull these back with a fine tip flat screwdriver and carefully pull our the ribbon. The next two have brown gates that hinge up. place a small flat blade under the gate and lift. the gates hinge up and the ribbons come loose. The next 3 are simple pull our ribbons. They all have tabs on the side to pull/push on. the one at 6 o'clock is already removed. There is 1 screw holding the pc board onto the lens body.
The screw in the white circle is the culprit in the jammed zoom ring. They tend to work themselves loose. Especially in a lens that has been dropped.
In My case the screw had come completly out and was lodged down beside the front element. the slider that it connects to in the inner zoom barrel had slipped and was stuck as well. I had to continue well passed this point to get the lens repaired.