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**Nakedgun** · 08-08-2018, 04:56 PM

Two lenses conk out this week.

First, my SDM DA*55 quits, which I was expecting for a while now, then the DA16-85 gives up.

Cleaned the 16-85 contacts, tried it on several cameras, no luck.

It will focus manually, and when the focus motor is energized it tries to move the focus group, and that can be felt when touching the focus ring, but it won't budge under power.

Brother!

photoptimist · 08-08-2018, 05:17 PM

Is there any chance that the body's AF electronics have failed? (Hopefully not!)

Do you have any other SDM lenses that do work with your body? Can you try these two lenses on another body?

Good luck!

aleonx3 · 08-08-2018, 05:35 PM

Do you have another body to test the lenses that failed? Chance of having more than one lens fail at the same time seems a little suspicious to me.

**jatrax** · 08-08-2018, 05:38 PM - **2 Likes**

Seems a lot of odd coincidence so I would look at the camera first.

On the DA 16-85 it might not be the motor but rather a loose screw inside. Several people have had that issue including me. The screw gets loose and jams up the internals depending on where it settles.

**Nakedgun** · 08-08-2018, 07:09 PM

I mentioned in the original post that they were non-functional on other cameras, as well..

The 55 had been squeeking for a while now, sure sign of impending failure.

Jatrax, thanks for the tip on the 16-85 screw, I will look into that.

**jatrax** · 08-08-2018, 08:09 PM

Originally posted by Nakedgun

The 55 had been squeeking for a while now, sure sign of impending failure.

Yep. Just got my 60-250 back from Advanced camera, they replaced the SDM motor. It had squeaked and putter for a long time before finally giving up completely.

On the 16-85 if I moved the focus ring and held it just right the screw would move about inside. Then end up up someplace else that jammed things up. Sent it in for repair at Precision and it was fixed under warranty.

**Rondec** · 08-09-2018, 02:35 AM - **1 Like**

The 55 is an SDM motor, so doesn't quite fit with the DC motor thing. But honestly, any time you have a motor in your lens, it can (and will eventually) break. Not trying to be pessimistic, but entropy works on lenses just as it works on everything else. The rate of failure with DC motors seems acceptably small, but the best thing if you are worried about it is to only by screw driven lenses or better yet, manual focus lenses.

Jonathan Mac · 08-09-2018, 03:38 AM - **1 Like**

Originally posted by jatrax

Seems a lot of odd coincidence so I would look at the camera first.

On the DA 16-85 it might not be the motor but rather a loose screw inside. Several people have had that issue including me. The screw gets loose and jams up the internals depending on where it settles.

This is what made me wary of the 16-85mm.

SDM motors (at least the older ones) are really bad for failing but any other type of motor can also fail. I've read about Canon and Fujifilm lens motors also conking out. In-lens AF motors are nice but they're one more thing to go wrong in the lens.

Check with another body and if that doesn't fix it then send them in somewhere to be looked at.

**jatrax** · 08-09-2018, 07:33 AM

Originally posted by Jonathan Mac

This is what made me wary of the 16-85mm.SDM motors (at least the older ones) are really bad for failing but any other type of motor can also fail.

I'll respond since you quoted me and only to clarify. Yes the old style SDM motors have a bad reputation. But the DA 16-85 is NOT SDM and has a sterling reputation with no motor failures I am aware of. It has had a few reports of a screw coming loose inside that jammed things up. That happened on mine and it was fixed under warranty. This was not a motor problem.

Ontarian50 · 08-09-2018, 07:40 AM

What amazes me about this issue, is how in-body AF motors are virtually bulletproof in comparison to their in-lens counterparts.

For decades now, we've seen cameras from Minolta, Nikon, and Pentax with AF motors in the body using "screw drive" to operate. And I'm certain I've never seen one of them die. Old bodies fail for many other reasons, but AF motors don't seem to be a weak spot.

So the puzzle is why the motor types used in lenses are so much more prone to failure?

Jonathan Mac · 08-10-2018, 02:42 AM

Originally posted by jatrax

I'll respond since you quoted me and only to clarify. Yes the old style SDM motors have a bad reputation. But the DA 16-85 is NOT SDM and has a sterling reputation with no motor failures I am aware of. It has had a few reports of a screw coming loose inside that jammed things up. That happened on mine and it was fixed under warranty. This was not a motor problem.

Yes, I know, I didn't mean to suggest that the 16-85mm had an SDM motor, but that doesn't mean it can't fail. Anything can fail.

Originally posted by Ontarian50

What amazes me about this issue, is how in-body AF motors are virtually bulletproof in comparison to their in-lens counterparts.

For decades now, we've seen cameras from Minolta, Nikon, and Pentax with AF motors in the body using "screw drive" to operate. And I'm certain I've never seen one of them die. Old bodies fail for many other reasons, but AF motors don't seem to be a weak spot.

So the puzzle is why the motor types used in lenses are so much more prone to failure?

I think it's because there's pressure on in-lens motors to be small, quiet and very fast. These are three qualities which don't go hand-in-hand with reliability.

**Nakedgun** · 08-18-2018, 06:33 PM

Originally posted by jatrax

the DA 16-85 is NOT SDM and has a sterling reputation with no motor failures I am aware of. It has had a few reports of a screw coming loose inside that jammed things up. That happened on mine and it was fixed under warranty. This was not a motor problem.

My lens not being under warranty I thought I would try to disassemble it to investigate the screw angle. Picked it up and vigorously worked the focus ring, again, by hand for a bit and felt it free up somewhat. Mounted it and now it auto-focuses again.

Assuming it is the loose-screw-syndrome I will attempt the disassembly myself if it jams up. I bought this lens June 2015 and wonder if the issue is something now corrected in the assembly plant?

**jatrax** · 08-19-2018, 08:09 PM

Originally posted by Nakedgun

I bought this lens June 2015 and wonder if the issue is something now corrected in the assembly plant?

No idea. In normal production changes are made when things like this are discovered. But with lenses, as I understand it, they are made in batches. So perhaps second run adds more locktite or whatever but not sure what that means to existing ones. And not sure how big an issue it is either. I think yours is the 4th I have heard of including mine.

Originally posted by Nakedgun

Assuming it is the loose-screw-syndrome I will attempt the disassembly myself if it jams up.

You are far, far braver than I am. Good luck.

08-08-2018, 04:56 PM	#1
Nakedgun Loyal Site Supporter Join Date: Apr 2014 Location: Southwest Posts: 1,365	I thought the DC motors weren't failing (as much?) Two lenses conk out this week. First, my SDM DA*55 quits, which I was expecting for a while now, then the DA16-85 gives up. Cleaned the 16-85 contacts, tried it on several cameras, no luck. It will focus manually, and when the focus motor is energized it tries to move the focus group, and that can be felt when touching the focus ring, but it won't budge under power. Brother!

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08-08-2018, 05:17 PM	#2
photoptimist Pentaxian Join Date: Jul 2016 Photos: Albums Posts: 5,129	Is there any chance that the body's AF electronics have failed? (Hopefully not!) Do you have any other SDM lenses that do work with your body? Can you try these two lenses on another body? Good luck!

08-08-2018, 05:35 PM	#3
aleonx3 Veteran Member Join Date: Jul 2007 Location: Brampton, Ontario Photos: Gallery \| Albums Posts: 3,996	Do you have another body to test the lenses that failed? Chance of having more than one lens fail at the same time seems a little suspicious to me.

08-08-2018, 05:38 PM - 2 Likes	#4
jatrax Site Supporter Join Date: May 2010 Location: Washington Cascades Photos: Gallery \| Albums Posts: 12,991	Seems a lot of odd coincidence so I would look at the camera first. On the DA 16-85 it might not be the motor but rather a loose screw inside. Several people have had that issue including me. The screw gets loose and jams up the internals depending on where it settles.

08-08-2018, 07:09 PM	#5
Nakedgun Loyal Site Supporter Join Date: Apr 2014 Location: Southwest Posts: 1,365 Original Poster	I mentioned in the original post that they were non-functional on other cameras, as well.. The 55 had been squeeking for a while now, sure sign of impending failure. Jatrax, thanks for the tip on the 16-85 screw, I will look into that.

08-08-2018, 08:09 PM	#6
jatrax Site Supporter Join Date: May 2010 Location: Washington Cascades Photos: Gallery \| Albums Posts: 12,991	Originally posted by Nakedgun The 55 had been squeeking for a while now, sure sign of impending failure. Yep. Just got my 60-250 back from Advanced camera, they replaced the SDM motor. It had squeaked and putter for a long time before finally giving up completely. On the 16-85 if I moved the focus ring and held it just right the screw would move about inside. Then end up up someplace else that jammed things up. Sent it in for repair at Precision and it was fixed under warranty.

08-09-2018, 02:35 AM - 1 Like	#7
Rondec Loyal Site Supporter Join Date: Mar 2009 Location: Gladys, Virginia Photos: Gallery Posts: 27,666	The 55 is an SDM motor, so doesn't quite fit with the DC motor thing. But honestly, any time you have a motor in your lens, it can (and will eventually) break. Not trying to be pessimistic, but entropy works on lenses just as it works on everything else. The rate of failure with DC motors seems acceptably small, but the best thing if you are worried about it is to only by screw driven lenses or better yet, manual focus lenses.

08-09-2018, 03:38 AM - 1 Like	#8
Jonathan Mac Pentaxian Join Date: Apr 2009 Location: Madrid, Spain Posts: 10,911	Originally posted by jatrax Seems a lot of odd coincidence so I would look at the camera first. On the DA 16-85 it might not be the motor but rather a loose screw inside. Several people have had that issue including me. The screw gets loose and jams up the internals depending on where it settles. This is what made me wary of the 16-85mm. SDM motors (at least the older ones) are really bad for failing but any other type of motor can also fail. I've read about Canon and Fujifilm lens motors also conking out. In-lens AF motors are nice but they're one more thing to go wrong in the lens. Check with another body and if that doesn't fix it then send them in somewhere to be looked at.

08-09-2018, 07:33 AM	#9
jatrax Site Supporter Join Date: May 2010 Location: Washington Cascades Photos: Gallery \| Albums Posts: 12,991	Originally posted by Jonathan Mac This is what made me wary of the 16-85mm.SDM motors (at least the older ones) are really bad for failing but any other type of motor can also fail. I'll respond since you quoted me and only to clarify. Yes the old style SDM motors have a bad reputation. But the DA 16-85 is NOT SDM and has a sterling reputation with no motor failures I am aware of. It has had a few reports of a screw coming loose inside that jammed things up. That happened on mine and it was fixed under warranty. This was not a motor problem.

08-09-2018, 07:40 AM	#10
Ontarian50 Veteran Member Join Date: Mar 2015 Posts: 530	What amazes me about this issue, is how in-body AF motors are virtually bulletproof in comparison to their in-lens counterparts. For decades now, we've seen cameras from Minolta, Nikon, and Pentax with AF motors in the body using "screw drive" to operate. And I'm certain I've never seen one of them die. Old bodies fail for many other reasons, but AF motors don't seem to be a weak spot. So the puzzle is why the motor types used in lenses are so much more prone to failure?

08-10-2018, 02:42 AM	#11
Jonathan Mac Pentaxian Join Date: Apr 2009 Location: Madrid, Spain Posts: 10,911	Originally posted by jatrax I'll respond since you quoted me and only to clarify. Yes the old style SDM motors have a bad reputation. But the DA 16-85 is NOT SDM and has a sterling reputation with no motor failures I am aware of. It has had a few reports of a screw coming loose inside that jammed things up. That happened on mine and it was fixed under warranty. This was not a motor problem. Yes, I know, I didn't mean to suggest that the 16-85mm had an SDM motor, but that doesn't mean it can't fail. Anything can fail. Originally posted by Ontarian50 What amazes me about this issue, is how in-body AF motors are virtually bulletproof in comparison to their in-lens counterparts. For decades now, we've seen cameras from Minolta, Nikon, and Pentax with AF motors in the body using "screw drive" to operate. And I'm certain I've never seen one of them die. Old bodies fail for many other reasons, but AF motors don't seem to be a weak spot. So the puzzle is why the motor types used in lenses are so much more prone to failure? I think it's because there's pressure on in-lens motors to be small, quiet and very fast. These are three qualities which don't go hand-in-hand with reliability.

08-18-2018, 06:33 PM	#12
Nakedgun Loyal Site Supporter Join Date: Apr 2014 Location: Southwest Posts: 1,365 Original Poster	Originally posted by jatrax the DA 16-85 is NOT SDM and has a sterling reputation with no motor failures I am aware of. It has had a few reports of a screw coming loose inside that jammed things up. That happened on mine and it was fixed under warranty. This was not a motor problem. My lens not being under warranty I thought I would try to disassemble it to investigate the screw angle. Picked it up and vigorously worked the focus ring, again, by hand for a bit and felt it free up somewhat. Mounted it and now it auto-focuses again. Assuming it is the loose-screw-syndrome I will attempt the disassembly myself if it jams up. I bought this lens June 2015 and wonder if the issue is something now corrected in the assembly plant?

08-19-2018, 08:09 PM	#13
jatrax Site Supporter Join Date: May 2010 Location: Washington Cascades Photos: Gallery \| Albums Posts: 12,991	Originally posted by Nakedgun I bought this lens June 2015 and wonder if the issue is something now corrected in the assembly plant? No idea. In normal production changes are made when things like this are discovered. But with lenses, as I understand it, they are made in batches. So perhaps second run adds more locktite or whatever but not sure what that means to existing ones. And not sure how big an issue it is either. I think yours is the 4th I have heard of including mine. Originally posted by Nakedgun Assuming it is the loose-screw-syndrome I will attempt the disassembly myself if it jams up. You are far, far braver than I am. Good luck.

I thought the DC motors weren't failing (as much?)

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