Disassembly and repair SMC Pentax-M ZOOM 1:3.5 28mm 1~4.5 50mm

1 – Remove the safety ring with the friction rubber disc label by unscrewing.
2 – Remove the profile tire from the focus ring.

Now, develop the 3 screws that were hidden from the rubber ring and pull the metal cylinder up.

These 3 screws are used to precisely focus the infinity lens. If you need such a setting, you need to develop them so much that you release the focus ring. Then place it in the middle between the smallest focal length and the largest and turn one of them, focus precisely, gently twist the screw that you twist, turn the focal ring to infinite – careful not to move the optical block and turn and 3 screws – that’s it. If you want to get to the aperture in order to dismantle it, you need to remove the stop pin to develop the helicoid along with the optical block. Mark the spot where the helicopter comes out carefully!

Remove and remove all screws from the back of the male bayonet. Take the bayonet carefully.

Pull the aperture ring out by taking care not to take the shot.

Below you will see 3 pairs of headless screws located exactly like this. Develop them not only until the hull has been released. Remove it by pulling it. Of course, you should unlock the aperture screw completely and remove it.

On the underside you will see the screw to adjust the clamping force of the aperture closing mechanism.

Remove the brass ring.

Run the 2 screws that hold the protective ring and remove it.

1 – If you develop the outer ring, you will remove the entire rear optical block – that’s what I did. It should be noted that reaching the optical components is on both sides. It is not possible to remove all optical elements unilaterally. But if you only need to work on the backs, then you only need to unroll the ring marked with – 2.

On the inside, the retaining ring is friction and threaded.

The lens with the disassembled rear optical block.