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*IST-DS shutter won't fire in AF mode


New Member

Have any members had a problem where a *IST-DS works normally in manual mode, with either AF or MF lenses but, in AF mode, fails to fire the shutter? The lens cycles in and out of focus but never locks on sharp focus and never fires. Several lenses have been tried on the problem body and all display the same shortcoming. The same lenses work perfectly on my K10D body.

I have been advised to blow out the mirror box with canned air but this has not helped. One quote to repair this body was $235, which is, I believe, roughly what the body is worth on the used market if it were working correctly.

Any advice?



New Member
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According to page 119 of your owner's manual, "The shutter cannot be released until the subject is in focus in AF mode. Adjust the focus manually if the subject is difficult to focus."

It would seem therefore that your autofocusing system is defective.

Wondering if cleaning the electrical contacts on the bayonet mount might help?


New Member
Cleaning contacts didn't work

Thanks for the advice.

I have tried cleaning the contacts on the bayonet flange on the body both with a fast-evaporating solvent and with a pencil eraser. Since the failure occurs with any of several AF lenses, their contacts don't seem to be in question. I cleaned the lenses, too, "just to be sure."

None of this made any difference.

Any other ideas, anybody?