Question on repairs to DA 17-70 SDM motors and 16-85 reliability

jddwoods · 10-18-2017, 05:08 PM

Hello All

I am looking for feedback from anyone who has a DA17-70 that had the SDM motor replaced. The SDM on my 17-70 finally died completely and I am wondering how successful repairs to this lens are. The repair is quite expensive and I am apprehensive about doing it if the replacement motor is likely to fail again. I would like to hear from anyone who has this lens and had this repair done. Is the replacement motor likely to be reliable or could I be looking at it failing again within a year or two?
Second question, I recently got a used DA 16-85. The autofocus works perfectly on this lens which uses DC rather than SDM. Can I expect this lens to have better reliability than the DA 17-70. I have not heard about failure issues with this lens but any feedback would be appreciated.

Thanks, John

GlennG · 10-18-2017, 05:45 PM

Good evening, John. I have the DA 17-70 and had the SDM repaired in early 2014. The repair was done in Chandler, AZ (forget the name - CRSS?) and they reported that they installed the updated SDM motor, so it should perform better and more reliably than the original. The SDM was good for about a year or so, but eventually the SDM issues returned. In almost all scenes the lens has trouble focusing in the 50-70 mm focal range. You can fiddle with it enough to get the camera to eventually take the photo, but it may not be in good focus. Also, and I'm not sure if this is related, the camera will often return the reported focal length as "43", which seems to be a default setting of sorts for when there is a focusing problem. I took my DA 17-70 on a recent trip to Hawaii when my DA 16-50 was unavailable. I got some great photos with the DA 17-70, especially in the under 50 mm range, but the overall experience brought back the frustrations I had when using the lens. It is unfortunate that this lens has this focusing issue. If the SDM could be bypassed like some other Pentax lenses I would gladly do that, but that option is not available. I love the photos, range, constant aperture that come with the DA 17-70; when it was right it was such a PERFECT walk around and travel lens for me. At this point, the 16-50 is my main lens and the 17-70 sits, waiting for me to come up with a forward plan for it. Not sure what it will be, though. At any rate, that is all the input I have for now. I hope you can glean a little useful perspective from this. Thanks. Glenn

Adam · 10-18-2017, 08:17 PM

Originally posted by jddwoods

Hello All

I am looking for feedback from anyone who has a DA17-70 that had the SDM motor replaced. The SDM on my 17-70 finally died completely and I am wondering how successful repairs to this lens are. The repair is quite expensive and I am apprehensive about doing it if the replacement motor is likely to fail again. I would like to hear from anyone who has this lens and had this repair done. Is the replacement motor likely to be reliable or could I be looking at it failing again within a year or two?
Second question, I recently got a used DA 16-85. The autofocus works perfectly on this lens which uses DC rather than SDM. Can I expect this lens to have better reliability than the DA 17-70. I have not heard about failure issues with this lens but any feedback would be appreciated.

Thanks, John

Even if you get a good repair job, the 16-85mm (or any other DC lens) will be more reliable, as it's a completely different technology that's not prone to the same kind of failure.

**UncleVanya** · 10-19-2017, 07:23 AM

The 17-70 I purchased two or more years ago refurbished (which I took to include SDM replacement) has never given any trouble. It is my niece's primary lens on her KS2. It is in fact her only lens and she uses it just about every day.

**hyyz** · 10-19-2017, 09:07 AM

GlennG and UncleVanya's above posts clearly show how unpredictable SDM on this lens (maybe other SDM lenses as well) is! One shows how troubling SDM is, while the other shows otherwise. Sadly, my 17-70mm falls into the former. With this, how can you have any confidence with SDM?

My advice: If one doesn't already have an SDM lens, avoid it. If one already has one, live with it. Don't try to repair SDM since there's no predictable result.

**twilhelm** · 10-19-2017, 11:57 AM

I fall into the latter camp. I’ve had mine for years, shot many weddings and events with it and never had SDM failure. The silence of SDM is nice, but a DC motor is leagues better. I wish they had used DC more.

**UncleVanya** · 10-19-2017, 01:21 PM

Honestly the 17-70 is a really nice lens - I wish the 16-85 had been a more direct replacement of the 17-70 which really is a fine lens.

jddwoods · 10-19-2017, 01:57 PM

Originally posted by GlennG

Good evening, John. I have the DA 17-70 and had the SDM repaired in early 2014. The repair was done in Chandler, AZ (forget the name - CRSS?) and they reported that they installed the updated SDM motor, so it should perform better and more reliably than the original. The SDM was good for about a year or so, but eventually the SDM issues returned. In almost all scenes the lens has trouble focusing in the 50-70 mm focal range. You can fiddle with it enough to get the camera to eventually take the photo, but it may not be in good focus. Also, and I'm not sure if this is related, the camera will often return the reported focal length as "43", which seems to be a default setting of sorts for when there is a focusing problem. I took my DA 17-70 on a recent trip to Hawaii when my DA 16-50 was unavailable. I got some great photos with the DA 17-70, especially in the under 50 mm range, but the overall experience brought back the frustrations I had when using the lens. It is unfortunate that this lens has this focusing issue. If the SDM could be bypassed like some other Pentax lenses I would gladly do that, but that option is not available. I love the photos, range, constant aperture that come with the DA 17-70; when it was right it was such a PERFECT walk around and travel lens for me. At this point, the 16-50 is my main lens and the 17-70 sits, waiting for me to come up with a forward plan for it. Not sure what it will be, though. At any rate, that is all the input I have for now. I hope you can glean a little useful perspective from this. Thanks. Glenn

Glenn (and all who responded)

Thank You Very Much. Your experiences are exactly same as mine. The first sign of trouble was the autofocus was hit or miss between 50 and 70mm and in the last few years I noticed if I did not use, or exercise it at least twice a week the SDM would be slow to start working. The repair is expensive $213 at precision plus the cost of shipping it. Based on the user reviews and the responses I received here this lens is something of a gamble. If you get a good one it is a really nice lens, but if you get a problematic one it is frustrating. My dilemma is with three bodies: K10D. K-5 and K-3 on a family outing all in use the 16-85 can't be on all of them. I am good with primes, but my wife and son want the convenience of a zoom. So for now, my 17-70 is a paperweight and I may look at another replacement, perhaps even one of the kit zooms 18-55 WR to 18-50 RE for my wife or son to use where they won't be as picky about image quality and camera weight as me. I noticed KEH and B&H both have used DA17-70 lenses in like new condition for not much more than fixing the one I have. My dilemma, Should I take another gamble on one of them?

**hyyz** · 10-19-2017, 02:14 PM

Given the fact that 17-70mm is not weather sealed, I suspect a used 18-135mm might be a better choice if you have to buy another zoom, IMO. No gamble with 18-135mm and its image quality is decent.

jddwoods · 10-19-2017, 04:34 PM

Originally posted by hyyz

Given the fact that 17-70mm is not weather sealed, I suspect a used 18-135mm might be a better choice if you have to buy another zoom, IMO. No gamble with 18-135mm and its image quality is decent.

Really good suggestion. Thanks. If I need serious image quality, I have primes (DA21, 40, 70 Limited trio).

**mikesbike** · 10-19-2017, 05:26 PM

I also recommend the DA 18-135mm. That way, you gain the extra tele range when you may need it. Its quality is very good, especially between 18-70mm, but still quite good beyond. Its AF performance is among the very best I have experienced in all my AF lenses. Fast, quiet, and sure. it is very compact and yet very well made.

Kozlok · 10-19-2017, 07:43 PM

If you don't need WR, the old screwdrive Sigma 17-70 is a great alternative

jddwoods · 10-20-2017, 04:14 PM

Brooke: First of all Great Pictures, I admire your photography. The key 2 words in your post are: "constant use" I have other lenses that I use, and any of them could be idle for a week to a month. For my DA 17-70, that is where the trouble began. If I used it daily it worked just fine. If I did not use it for a week it would be "sleepy" but it would get going after a few minutes, two weeks and it became an ordeal to get the autofocus working. Due to me being away from photography for a month was just too much and after hours of trying on my K-5 and K-3 without success, I gave up on it. It you keep it going it is a great lens as your pictures very clearly demonstrate. For me, I moved on to the DA 16-85 (no autofocus issues with this one), but would like to get a backup normal zoom at some point for family use.

**twilhelm** · 10-20-2017, 04:21 PM

Originally posted by jddwoods

Brooke: First of all Great Pictures, I admire your photography. The key 2 words in your post are: "constant use" I have other lenses that I use, and any of them could be idle for a week to a month. For my DA 17-70, that is where the trouble began. If I used it daily it worked just fine. If I did not use it for a week it would be "sleepy" but it would get going after a few minutes, two weeks and it became an ordeal to get the autofocus working. Due to me being away from photography for a month was just too much and after hours of trying on my K-5 and K-3 without success, I gave up on it. It you keep it going it is a great lens as your pictures very clearly demonstrate. For me, I moved on to the DA 16-85 (no autofocus issues with this one), but would like to get a backup normal zoom at some point for family use.

You’re right about the 16-85 not having AF issues. But, as I stated before I haven’t had issues with the 17-70 and I let it sit a year without use ( I had other projects). When I picked it up it went to work as always.

I really think it is hit or miss with the 17-70. But optically I consider it to be on par with what I expect from a pro grade lens.

GlennG · 10-22-2017, 02:14 PM

Originally posted by twilhelm

I really think it is hit or miss with the 17-70. But optically I consider it to be on par with what I expect from a pro grade lens.

I concur with this, and in a further addition to my above post, I have not had any experience with the 16-85, but the photos I see on line are great. If I was doing it again I would probably just get the 16-85, as most of the time I don't need that fast of an aperture. I've used my 17-70 on only a K100d Super and K5, but it performs similarly on each, so I am thinking the focusing issues with my 17-70 is not a camera/lens compatibility thing.

10-18-2017, 05:08 PM	#1
jddwoods Pentaxian Join Date: Nov 2012 Location: Newark, Delaware Posts: 1,035	Question on repairs to DA 17-70 SDM motors and 16-85 reliability Hello All I am looking for feedback from anyone who has a DA17-70 that had the SDM motor replaced. The SDM on my 17-70 finally died completely and I am wondering how successful repairs to this lens are. The repair is quite expensive and I am apprehensive about doing it if the replacement motor is likely to fail again. I would like to hear from anyone who has this lens and had this repair done. Is the replacement motor likely to be reliable or could I be looking at it failing again within a year or two? Second question, I recently got a used DA 16-85. The autofocus works perfectly on this lens which uses DC rather than SDM. Can I expect this lens to have better reliability than the DA 17-70. I have not heard about failure issues with this lens but any feedback would be appreciated. Thanks, John

10-18-2017, 08:17 PM	#3
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,597	Originally posted by jddwoods Hello All I am looking for feedback from anyone who has a DA17-70 that had the SDM motor replaced. The SDM on my 17-70 finally died completely and I am wondering how successful repairs to this lens are. The repair is quite expensive and I am apprehensive about doing it if the replacement motor is likely to fail again. I would like to hear from anyone who has this lens and had this repair done. Is the replacement motor likely to be reliable or could I be looking at it failing again within a year or two? Second question, I recently got a used DA 16-85. The autofocus works perfectly on this lens which uses DC rather than SDM. Can I expect this lens to have better reliability than the DA 17-70. I have not heard about failure issues with this lens but any feedback would be appreciated. Thanks, John Even if you get a good repair job, the 16-85mm (or any other DC lens) will be more reliable, as it's a completely different technology that's not prone to the same kind of failure. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

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10-18-2017, 05:45 PM	#2
GlennG Veteran Member Join Date: Aug 2010 Location: Houston, Texas Posts: 824	Good evening, John. I have the DA 17-70 and had the SDM repaired in early 2014. The repair was done in Chandler, AZ (forget the name - CRSS?) and they reported that they installed the updated SDM motor, so it should perform better and more reliably than the original. The SDM was good for about a year or so, but eventually the SDM issues returned. In almost all scenes the lens has trouble focusing in the 50-70 mm focal range. You can fiddle with it enough to get the camera to eventually take the photo, but it may not be in good focus. Also, and I'm not sure if this is related, the camera will often return the reported focal length as "43", which seems to be a default setting of sorts for when there is a focusing problem. I took my DA 17-70 on a recent trip to Hawaii when my DA 16-50 was unavailable. I got some great photos with the DA 17-70, especially in the under 50 mm range, but the overall experience brought back the frustrations I had when using the lens. It is unfortunate that this lens has this focusing issue. If the SDM could be bypassed like some other Pentax lenses I would gladly do that, but that option is not available. I love the photos, range, constant aperture that come with the DA 17-70; when it was right it was such a PERFECT walk around and travel lens for me. At this point, the 16-50 is my main lens and the 17-70 sits, waiting for me to come up with a forward plan for it. Not sure what it will be, though. At any rate, that is all the input I have for now. I hope you can glean a little useful perspective from this. Thanks. Glenn

10-19-2017, 07:23 AM	#4
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,445	The 17-70 I purchased two or more years ago refurbished (which I took to include SDM replacement) has never given any trouble. It is my niece's primary lens on her KS2. It is in fact her only lens and she uses it just about every day.

10-19-2017, 09:07 AM	#5
hyyz Site Supporter Join Date: Jan 2008 Location: Michigan Posts: 478	GlennG and UncleVanya's above posts clearly show how unpredictable SDM on this lens (maybe other SDM lenses as well) is! One shows how troubling SDM is, while the other shows otherwise. Sadly, my 17-70mm falls into the former. With this, how can you have any confidence with SDM? My advice: If one doesn't already have an SDM lens, avoid it. If one already has one, live with it. Don't try to repair SDM since there's no predictable result.

10-19-2017, 11:57 AM	#6
twilhelm Loyal Site Supporter Join Date: Feb 2009 Location: Florida Photos: Gallery \| Albums Posts: 2,369	I fall into the latter camp. I’ve had mine for years, shot many weddings and events with it and never had SDM failure. The silence of SDM is nice, but a DC motor is leagues better. I wish they had used DC more.

10-19-2017, 01:21 PM	#7
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,445	Honestly the 17-70 is a really nice lens - I wish the 16-85 had been a more direct replacement of the 17-70 which really is a fine lens.

10-19-2017, 01:57 PM	#8
jddwoods Pentaxian Join Date: Nov 2012 Location: Newark, Delaware Posts: 1,035 Original Poster	Originally posted by GlennG Good evening, John. I have the DA 17-70 and had the SDM repaired in early 2014. The repair was done in Chandler, AZ (forget the name - CRSS?) and they reported that they installed the updated SDM motor, so it should perform better and more reliably than the original. The SDM was good for about a year or so, but eventually the SDM issues returned. In almost all scenes the lens has trouble focusing in the 50-70 mm focal range. You can fiddle with it enough to get the camera to eventually take the photo, but it may not be in good focus. Also, and I'm not sure if this is related, the camera will often return the reported focal length as "43", which seems to be a default setting of sorts for when there is a focusing problem. I took my DA 17-70 on a recent trip to Hawaii when my DA 16-50 was unavailable. I got some great photos with the DA 17-70, especially in the under 50 mm range, but the overall experience brought back the frustrations I had when using the lens. It is unfortunate that this lens has this focusing issue. If the SDM could be bypassed like some other Pentax lenses I would gladly do that, but that option is not available. I love the photos, range, constant aperture that come with the DA 17-70; when it was right it was such a PERFECT walk around and travel lens for me. At this point, the 16-50 is my main lens and the 17-70 sits, waiting for me to come up with a forward plan for it. Not sure what it will be, though. At any rate, that is all the input I have for now. I hope you can glean a little useful perspective from this. Thanks. Glenn Glenn (and all who responded) Thank You Very Much. Your experiences are exactly same as mine. The first sign of trouble was the autofocus was hit or miss between 50 and 70mm and in the last few years I noticed if I did not use, or exercise it at least twice a week the SDM would be slow to start working. The repair is expensive $213 at precision plus the cost of shipping it. Based on the user reviews and the responses I received here this lens is something of a gamble. If you get a good one it is a really nice lens, but if you get a problematic one it is frustrating. My dilemma is with three bodies: K10D. K-5 and K-3 on a family outing all in use the 16-85 can't be on all of them. I am good with primes, but my wife and son want the convenience of a zoom. So for now, my 17-70 is a paperweight and I may look at another replacement, perhaps even one of the kit zooms 18-55 WR to 18-50 RE for my wife or son to use where they won't be as picky about image quality and camera weight as me. I noticed KEH and B&H both have used DA17-70 lenses in like new condition for not much more than fixing the one I have. My dilemma, Should I take another gamble on one of them?

10-19-2017, 02:14 PM	#9
hyyz Site Supporter Join Date: Jan 2008 Location: Michigan Posts: 478	Given the fact that 17-70mm is not weather sealed, I suspect a used 18-135mm might be a better choice if you have to buy another zoom, IMO. No gamble with 18-135mm and its image quality is decent.

10-19-2017, 04:34 PM	#10
jddwoods Pentaxian Join Date: Nov 2012 Location: Newark, Delaware Posts: 1,035 Original Poster	Originally posted by hyyz Given the fact that 17-70mm is not weather sealed, I suspect a used 18-135mm might be a better choice if you have to buy another zoom, IMO. No gamble with 18-135mm and its image quality is decent. Really good suggestion. Thanks. If I need serious image quality, I have primes (DA21, 40, 70 Limited trio).

10-19-2017, 05:26 PM	#11
mikesbike Site Supporter Join Date: Dec 2016 Location: Southeastern Michigan Posts: 4,558	I also recommend the DA 18-135mm. That way, you gain the extra tele range when you may need it. Its quality is very good, especially between 18-70mm, but still quite good beyond. Its AF performance is among the very best I have experienced in all my AF lenses. Fast, quiet, and sure. it is very compact and yet very well made.

10-19-2017, 07:43 PM	#12
Kozlok Pentaxian Join Date: Jun 2012 Location: Albuquerque Photos: Gallery Posts: 3,148	If you don't need WR, the old screwdrive Sigma 17-70 is a great alternative

10-20-2017, 04:14 PM	#13
jddwoods Pentaxian Join Date: Nov 2012 Location: Newark, Delaware Posts: 1,035 Original Poster	Brooke: First of all Great Pictures, I admire your photography. The key 2 words in your post are: "constant use" I have other lenses that I use, and any of them could be idle for a week to a month. For my DA 17-70, that is where the trouble began. If I used it daily it worked just fine. If I did not use it for a week it would be "sleepy" but it would get going after a few minutes, two weeks and it became an ordeal to get the autofocus working. Due to me being away from photography for a month was just too much and after hours of trying on my K-5 and K-3 without success, I gave up on it. It you keep it going it is a great lens as your pictures very clearly demonstrate. For me, I moved on to the DA 16-85 (no autofocus issues with this one), but would like to get a backup normal zoom at some point for family use.

10-20-2017, 04:21 PM	#14
twilhelm Loyal Site Supporter Join Date: Feb 2009 Location: Florida Photos: Gallery \| Albums Posts: 2,369	Originally posted by jddwoods Brooke: First of all Great Pictures, I admire your photography. The key 2 words in your post are: "constant use" I have other lenses that I use, and any of them could be idle for a week to a month. For my DA 17-70, that is where the trouble began. If I used it daily it worked just fine. If I did not use it for a week it would be "sleepy" but it would get going after a few minutes, two weeks and it became an ordeal to get the autofocus working. Due to me being away from photography for a month was just too much and after hours of trying on my K-5 and K-3 without success, I gave up on it. It you keep it going it is a great lens as your pictures very clearly demonstrate. For me, I moved on to the DA 16-85 (no autofocus issues with this one), but would like to get a backup normal zoom at some point for family use. You’re right about the 16-85 not having AF issues. But, as I stated before I haven’t had issues with the 17-70 and I let it sit a year without use ( I had other projects). When I picked it up it went to work as always. I really think it is hit or miss with the 17-70. But optically I consider it to be on par with what I expect from a pro grade lens.

10-22-2017, 02:14 PM	#15
GlennG Veteran Member Join Date: Aug 2010 Location: Houston, Texas Posts: 824	Originally posted by twilhelm I really think it is hit or miss with the 17-70. But optically I consider it to be on par with what I expect from a pro grade lens. I concur with this, and in a further addition to my above post, I have not had any experience with the 16-85, but the photos I see on line are great. If I was doing it again I would probably just get the 16-85, as most of the time I don't need that fast of an aperture. I've used my 17-70 on only a K100d Super and K5, but it performs similarly on each, so I am thinking the focusing issues with my 17-70 is not a camera/lens compatibility thing.