K3 stuck in MF

snostorm · 03-09-2015, 07:34 AM

Originally posted by stevebrot

...or having the A-contacts. If the "A" contact ("*" in diagram below) is not detected, AF will not be attempted.

It's good that the OP found a cure, but I feel compelled to add a post because I believe this statement is not accurate. IIRC the "A" contact transmits aperture information (min/max and Av from the lens if the aperture ring is set to "A").

The "Data" contact, which is the bottom-most of the seven body contacts (and not shown in the above diagram), transmits the rest of the lens info (model, screw drive/SDM, MTF in FA and later models, etc). If this contact is not functioning correctly, then the body can assume an MF lens is mounted.

Scott

Sigmund · 03-09-2015, 01:19 PM

Ah well, it's not over.

Midway through a session with the Sigma the AE went on the blink and the EXIF data for those shots reckoned the focal length was 2.5 m!

Swapping back to Pentax lenses brought back the AF failure and the tickle and clean routine hasn't fixed it.

It's a waning moon. Maybe that's it.

Any mileage do you think in getting a drop of WD40 into that contact? It's all I've got and am likely to have for a week.

vonBaloney · 03-09-2015, 01:24 PM

Originally posted by Sigmund

Any mileage do you think in getting a drop of WD40 into that contact? It's all I've got and am likely to have for a week.

Don't do that. Electronic contact cleaner is ok, but WD40 is oily and could spread into other parts. (And does it even help conductivity?) Contact cleaner is what you want -- any hardware or auto parts store...

Sigmund · 03-09-2015, 01:35 PM

Originally posted by snostorm

It's good that the OP found a cure, but I feel compelled to add a post because I believe this statement is not accurate. IIRC the "A" contact transmits aperture information (min/max and Av from the lens if the aperture ring is set to "A").

The "Data" contact, which is the bottom-most of the seven body contacts (and not shown in the above diagram), transmits the rest of the lens info (model, screw drive/SDM, MTF in FA and later models, etc). If this contact is not functioning correctly, then the body can assume an MF lens is mounted.

Scott

Thanks Scott. Didn't notice your post as I was replying from p.1. Will focus on that contact (ahem).

---------- Post added 03-10-15 at 07:46 AM ----------

Originally posted by vonBaloney

Don't do that. Electronic contact cleaner is ok, but WD40 is oily and could spread into other parts. (And does it even help conductivity?) Contact cleaner is what you want -- any hardware or auto parts store...

Thanks vB. Will see if I can find some.

stevebrot · 03-09-2015, 05:56 PM

Originally posted by snostorm

It's good that the OP found a cure, but I feel compelled to add a post because I believe this statement is not accurate. IIRC the "A" contact transmits aperture information (min/max and Av from the lens if the aperture ring is set to "A").

The "Data" contact, which is the bottom-most of the seven body contacts (and not shown in the above diagram), transmits the rest of the lens info (model, screw drive/SDM, MTF in FA and later models, etc). If this contact is not functioning correctly, then the body can assume an MF lens is mounted.

Scott

You are correct. I have edited my original post.

Steve

Sigmund · 03-09-2015, 09:57 PM

Well once today I was able to return to AF with a tickle (of the 3rd contact) followed by a lens swap. But without a change of lens that setup switched to MF while I was hiking!

Wineglass Bay followed by Hazards Beach, Freycinet NP, Tasmania, Australia.

stevebrot · 03-10-2015, 10:21 AM

It sounds like maybe a service call may be in order.

Steve

Sigmund · 03-10-2015, 12:50 PM

Yes indeed. Not possible though as I'm travelling. It's back to the MF of my youth!

rburgoss · 03-11-2015, 10:30 AM

Hmmmm... so the problem came back? As I understand, it came back after using the same Sigma that showed the problem the first time?

If that's the case, I can see a pattern here, and its not your camera who needs servicing!

Sigmund · 03-11-2015, 12:49 PM

Yes, though it returns as well after being tickled back to life after the Sigma bite.

Do you have the K3 rburgoss? If so can you tell me whether the 3rd contact down is recessed?

rburgoss · 03-11-2015, 01:58 PM

Originally posted by Sigmund

Yes, though it returns as well after being tickled back to life after the Sigma bite.

Do you have the K3 rburgoss? If so can you tell me whether the 3rd contact down is recessed?

I can do better. This is my K3's mount contacts. They are identical to my K20D's. The 3rd contact is recessed. The 7th contact is (seems) gold.

stevebrot · 03-11-2015, 07:32 PM

Originally posted by Sigmund

If so can you tell me whether the 3rd contact down is recessed?

Originally posted by rburgoss

The 3rd contact is recessed

The third contact on the body is always recessed.

Steve

Sigmund · 03-11-2015, 08:18 PM

Thanks. I thought that'd be too simple a diagnosis.

The body produced some odd yellow casts amongst the normal hues in today's shoot. Sigh.

Sigmund · 03-21-2015, 11:15 AM

Update: the body has returned to good behaviour & I've no idea why. The Sigma doesn't reproduce the problem.

Not very confidence inspiring.

Thanks again all for your help.

rburgoss · 03-21-2015, 03:16 PM

Originally posted by Sigmund

Update: the body has returned to good behaviour & I've no idea why. The Sigma doesn't reproduce the problem.

Not very confidence inspiring.

Thanks again all for your help.

That is quite disturbing. Did you used the camera this days and just today it started be having normal, or is it that you didn't used it and just today you noticed it came back to normal behavior? If camera was not used, was the battery in it charged?

It is important to pinpoint and be able to reproduce the conditions on which the erratic behavior triggers. That will be the only way to know for sure which "link" is responsible: body, lens, battery, shooting conditions, etc.

Pls, keep us posted if anything happens again.

03-09-2015, 09:57 PM	#21
Sigmund Senior Member Join Date: Apr 2014 Location: Melbourne, Australia Posts: 142 Original Poster	Well once today I was able to return to AF with a tickle (of the 3rd contact) followed by a lens swap. But without a change of lens that setup switched to MF while I was hiking! Wineglass Bay followed by Hazards Beach, Freycinet NP, Tasmania, Australia. Attached Images

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03-09-2015, 07:34 AM	#16
snostorm Veteran Member Join Date: Oct 2006 Location: Chicago suburb, IL, USA Posts: 1,535	Originally posted by stevebrot ...or having the A-contacts. If the "A" contact ("" in diagram below) is not detected, AF will not be attempted. It's good that the OP found a cure, but I feel compelled to add a post because I believe this statement is not accurate. IIRC the "A" contact transmits aperture information (min/max and Av from the lens if the aperture ring is set to "A"). The "Data" contact, which is the bottom-most of the seven* body contacts (and not shown in the above diagram), transmits the rest of the lens info (model, screw drive/SDM, MTF in FA and later models, etc). If this contact is not functioning correctly, then the body can assume an MF lens is mounted. Scott

03-09-2015, 01:19 PM	#17
Sigmund Senior Member Join Date: Apr 2014 Location: Melbourne, Australia Posts: 142 Original Poster	Ah well, it's not over. Midway through a session with the Sigma the AE went on the blink and the EXIF data for those shots reckoned the focal length was 2.5 m! Swapping back to Pentax lenses brought back the AF failure and the tickle and clean routine hasn't fixed it. It's a waning moon. Maybe that's it. Any mileage do you think in getting a drop of WD40 into that contact? It's all I've got and am likely to have for a week.

03-09-2015, 01:24 PM	#18
vonBaloney Pentaxian Join Date: Oct 2011 Location: Albuquerque, NM Posts: 6,029	Originally posted by Sigmund Any mileage do you think in getting a drop of WD40 into that contact? It's all I've got and am likely to have for a week. Don't do that. Electronic contact cleaner is ok, but WD40 is oily and could spread into other parts. (And does it even help conductivity?) Contact cleaner is what you want -- any hardware or auto parts store...

03-09-2015, 01:35 PM	#19
Sigmund Senior Member Join Date: Apr 2014 Location: Melbourne, Australia Posts: 142 Original Poster	Originally posted by snostorm It's good that the OP found a cure, but I feel compelled to add a post because I believe this statement is not accurate. IIRC the "A" contact transmits aperture information (min/max and Av from the lens if the aperture ring is set to "A"). The "Data" contact, which is the bottom-most of the seven body contacts (and not shown in the above diagram), transmits the rest of the lens info (model, screw drive/SDM, MTF in FA and later models, etc). If this contact is not functioning correctly, then the body can assume an MF lens is mounted. Scott Thanks Scott. Didn't notice your post as I was replying from p.1. Will focus on that contact (ahem). ---------- Post added 03-10-15 at 07:46 AM ---------- Originally posted by vonBaloney Don't do that. Electronic contact cleaner is ok, but WD40 is oily and could spread into other parts. (And does it even help conductivity?) Contact cleaner is what you want -- any hardware or auto parts store... Thanks vB. Will see if I can find some.

03-09-2015, 05:56 PM	#20
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by snostorm It's good that the OP found a cure, but I feel compelled to add a post because I believe this statement is not accurate. IIRC the "A" contact transmits aperture information (min/max and Av from the lens if the aperture ring is set to "A"). The "Data" contact, which is the bottom-most of the seven body contacts (and not shown in the above diagram), transmits the rest of the lens info (model, screw drive/SDM, MTF in FA and later models, etc). If this contact is not functioning correctly, then the body can assume an MF lens is mounted. Scott You are correct. I have edited my original post. Steve

03-10-2015, 10:21 AM	#22
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	It sounds like maybe a service call may be in order. Steve

03-10-2015, 12:50 PM	#23
Sigmund Senior Member Join Date: Apr 2014 Location: Melbourne, Australia Posts: 142 Original Poster	Yes indeed. Not possible though as I'm travelling. It's back to the MF of my youth!

03-11-2015, 10:30 AM	#24
rburgoss Veteran Member Join Date: May 2008 Location: San Jose, Costa Rica Photos: Gallery \| Albums Posts: 972	Hmmmm... so the problem came back? As I understand, it came back after using the same Sigma that showed the problem the first time? If that's the case, I can see a pattern here, and its not your camera who needs servicing!

03-11-2015, 12:49 PM	#25
Sigmund Senior Member Join Date: Apr 2014 Location: Melbourne, Australia Posts: 142 Original Poster	Yes, though it returns as well after being tickled back to life after the Sigma bite. Do you have the K3 rburgoss? If so can you tell me whether the 3rd contact down is recessed?

03-11-2015, 07:32 PM	#27
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by Sigmund If so can you tell me whether the 3rd contact down is recessed? Originally posted by rburgoss The 3rd contact is recessed The third contact on the body is always recessed. Steve

03-11-2015, 08:18 PM	#28
Sigmund Senior Member Join Date: Apr 2014 Location: Melbourne, Australia Posts: 142 Original Poster	Thanks. I thought that'd be too simple a diagnosis. The body produced some odd yellow casts amongst the normal hues in today's shoot. Sigh.

03-21-2015, 11:15 AM	#29
Sigmund Senior Member Join Date: Apr 2014 Location: Melbourne, Australia Posts: 142 Original Poster	Update: the body has returned to good behaviour & I've no idea why. The Sigma doesn't reproduce the problem. Not very confidence inspiring. Thanks again all for your help.

03-21-2015, 03:16 PM	#30
rburgoss Veteran Member Join Date: May 2008 Location: San Jose, Costa Rica Photos: Gallery \| Albums Posts: 972	Originally posted by Sigmund Update: the body has returned to good behaviour & I've no idea why. The Sigma doesn't reproduce the problem. Not very confidence inspiring. Thanks again all for your help. That is quite disturbing. Did you used the camera this days and just today it started be having normal, or is it that you didn't used it and just today you noticed it came back to normal behavior? If camera was not used, was the battery in it charged? It is important to pinpoint and be able to reproduce the conditions on which the erratic behavior triggers. That will be the only way to know for sure which "link" is responsible: body, lens, battery, shooting conditions, etc. Pls, keep us posted if anything happens again.