Lens not functioning in manual mode

My SMC Pentax-DA 18-55 mm lens does not work in manual mode. I can try to change aperture but it doesn't chang the exposure of the image taken. In the metadata the aperture changes but not the actual exposure.

Shooting in P mode does not reveal any problems but I fear lens aperture is actually "frozen" at wide open.

Shooting in Av mode suggest this is right as images get overexposed when setting aperture to anything else than full open (smallest f value).

Have tried on both my K-3 and my K 200 and problem is on both cameras.

I have tried cleaning the lens contacts with paper tissue but no luck.

Years ago I changed from the K 200 to a K-3 because I thought I had damaged the K 200 when dropping it (with the actual lens on) - it sometimes gave way off exposures. Truth is perhaps that I damaged the lens, not the camera.....

Just adding: I can by hand manipulate the slider and see the aperture change inside the lens. But it doesn't jump back to fully closed as another lens I have.

Perhaps a spring broken/fallen off?

It looks like you might be right about the spring.

In Denmark wages are to high for sending a lens like this for repair. Cheaper to buy a new.

Have anybody tried themselves to disassemble a lens? And assemble it again also of course

Wow - the internet can still amaze me

Do you mean the screws I have marked on the photo below? (there are 4 of those, where 2 of them sit very close to each other)

Be careful not to damage the screw heads. Japanese Industry Standard (JIS) cross-head screws are slightly different to Phillips cross-head. I've just bought a set of JIS screwdrivers in order to remove a mount (from an extension tube) and it has made it easier to remove screws without fear of damage. They were fairly cheap from a UK importer at the usual auction site, not sure about availability elsewhere in Europe.

Steve

Yep, those ones, the back plastic cover will then lift out, it's got like a inner collar on it.

It can only go back on one way because of the window for the aperture lever.

The sixth picture on that link above, shows you the inside of the metal mount and how the plastic cover is fixed, looks like 3 screws.

Thanks - I think I will try with whatever small screwdriver I have. Buying a JIS screwdriver set will cost more than half of what I can buy a secondhand unused similar lens for not far from where I live.

And I am not sure I can fix the one I have.....

Just realized that by zooming fully in I can actually see the spring being in place as it should be

Some something else must be bent or something like that. Had it been some other sort of mechanics I may have tried some oil....

Now I think I will go for buying the secondhand unused lens as price is just Dkr 500 (67€ or $).

Perhaps I can negotiate price a little

A decent set of JIS screwdrivers should last a lifetime so it may be a decent investment.