You need the brass balls. On Tue, Jul 16, 2013 at 10:58 AM, John <johnsess...@yahoo.com> wrote: > Definitely sounds like the kind of headache I'd rather pay someone else to > deal with. > > > > On 7/15/2013 9:13 PM, Gerrit Visser wrote: >> >> The circuitry, such as it is which is basically tiny brass balls shorting >> or >> not shorting to the frame or one of the other balls, is directly below the >> rear mounting ring. If you take that off, do it slowly so that you can see >> which balls and springs go where. It could be something gunked up in >> there. >> There is no real circuitry inside the old A lenses AFAIK. (I have had >> several apart, and successfully reassembled them) >> >> Gerrit >> >> >> >> wiggle the lens in the mount; turn it off & dismount & remount the lens; >> turn it off & dismount the lens, clean the contacts on the lens & body and >> remount the lens ... >> >> When I turn it back on, maybe I'll get the focal length prompt again or >> maybe I'll get the last aperture I selected. >> >> If I *DO* get the aperture, it appears I'm going to get the "F--" again >> after a few shots. It's definitely something going on with the lens. >> I've tried it with a bunch of other lenses that have the aperture ring & >> an >> 'A' detent. They all work just fine. >> >> I've seen that "F--" before with several different lenses and it's always >> been when I somehow got the lens unlocked from the 'A' detent. As soon as >> I >> get the lens back in the 'A' position the problem goes away. >> >> I think something inside this lens that has to do with whatever circuit >> detects whether the lens is mechanically locked into the 'A' position or >> not >> is wearing out. >> >> >> On 7/15/2013 4:24 PM, Bob Sullivan wrote: >>> >>> And John, >>> Did you clean the contacts on the camera as well? >>> Regards, Bob S. >>> >>> On Mon, Jul 15, 2013 at 12:40 PM, John <johnsess...@yahoo.com> wrote: >>>> >>>> On 7/15/2013 1:03 PM, Zos Xavius wrote: >>>>> >>>>> >>>>> Did you try cleaning the contacts? There isn't an communication >>>>> between the lens and the camera for an A lens. It just reads the >>>>> contacts and determines aperture range. Try cleaning them. >>>>> >>>> >>>> Yup. That was something I learned from Army radios. >>>> >>>> Don't know why it stopped working. Don't know why it started working >>>> again once I got home. Don't know when it's going to decide to crap >>>> out again. >>>> >>>> But the contacts are clean. >>>> >>>> I (gently) racked the aperture ring several times from 'A' to 2.8 & >>>> back again to see if maybe some bit of grunge was keeping it from >>>> registering the 'A' position internally. >>>> >>>> I guess it's time to start looking for a backup/replacement before it >>>> fails for good. Looks like the only thing available is going to be >>>> either the 28-70 F2.8 SIGMA EX ASPHERICAL (77) or the 24-70 F2.8 >>>> SIGMA DG EX ASPHERICAL (82). >>>> >>>> Anyone have hands on experience comparing either of them with the >>>> Tokina ATX-Pro? >>>> >>>> >>>> >>>>> On Mon, Jul 15, 2013 at 12:59 PM, John <johnsess...@yahoo.com> wrote: >>>>>> >>>>>> >>>>>> I finally dredge up enough motivation to actually go out and do >>>>>> some photography. Got on site & my favorite lens takes a crap on me. >>>>>> >>>>>> My workhorse has been a Tokina ATX-Pro 287 28-70mmf/2.8. I got two >>>>>> frames & camera won't fire the shutter. Aperture shows "F--". I do >>>>>> everything I can to make sure the lens is properly seated & that >>>>>> the aperture ring is latched into the 'A' position ... NO JOY! >>>>>> Nothing I can do will make it show the aperture. >>>>>> >>>>>> I have one other 'A' lens (SMC Pentax-A Macro 1:2.8 100mm) in my >>>>>> bag on site, & when I switch to it the aperture works fine. I also >>>>>> try both lenses on my K10D (backup) and get the same results; >>>>>> Tokina "F--" & Pentax shows the aperture selected with the >>>>>> thumb-wheel. >>>>>> >>>>>> I'm back home & I've got a couple of other Pentax auto-focus 'A' >>>>>> lenses to test with. They all show the aperture & change with the >>>>>> thumb-wheel. And just to add insult to injury, I give the Tokina >>>>>> one last try & now it's showing the aperture again. >>>>>> >>>>>> Meanwhile, every bit of motivation has drained away! >>>> >>>> >>>> >>>> -- >>>> PDML Pentax-Discuss Mail List >>>> PDML@pdml.net >>>> http://pdml.net/mailman/listinfo/pdml_pdml.net >>>> to UNSUBSCRIBE from the PDML, please visit the link directly above >>>> and follow the directions. >>> >>> >> >> -- >> PDML Pentax-Discuss Mail List >> PDML@pdml.net >> http://pdml.net/mailman/listinfo/pdml_pdml.net >> to UNSUBSCRIBE from the PDML, please visit the link directly above and >> follow the directions. >> >> > > -- > PDML Pentax-Discuss Mail List > PDML@pdml.net > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and > follow the directions.
-- -bmw -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
