SMC Pentax-DA 21mm F3.2 Limited - Is it fixable?

Senko · 10-02-2019, 05:16 AM

Recently, my 21mm F3.2 Limited started experience auto focus issues out of nowhere. Worked perfectly one day, next day it wouldn't auto focus - i.e. nothing would happen when trying to focus, seems like the lens is 'locked up'.

In troubleshooting the lens I tried it on 3 different bodies, cleaned the contacts, and still had the same issue. I can get it to focus sometimes by using the quick shift and focusing on something else but after a shot or two the same issue reoccurs and it locks up again.

I've done a forum search and seen other people experience similar issues and even resort to disassembling the lens to fix it. My local camera repair shop does not work on Pentax and I am leery about taking the lens apart for a DIY fix.

Before going this route can anyone have any other suggestions on a good resource / guide to fixing this lens myself?

Thanks.

Sandy Hancock · 10-02-2019, 05:29 AM

UncleVanya may have some some history here IIRC.

Kozlok · 10-02-2019, 05:34 AM

My guess is it’s the start of what happened to my 21. You need to tighten the screws that hold the lens group into the lens. Mine fell completely out.

Need HELP DA21 Self-Disassembled! - PentaxForums.com

The only odd bit is the middle front trim ring is held on by tape, you must pry it off gently.

Sandy Hancock · 10-02-2019, 05:38 AM - **1 Like**

Originally posted by Kozlok

My guess is it’s the start of what happened to my 21. You need to tighten the screws that hold the lens group into the lens. Mine fell completely out.

Need HELP DA21 Self-Disassembled! - PentaxForums.com

The only odd bit is the middle front trim ring is held on by tape, you must pry it off gently.

Ah! My bad. It was Keith, not Brad

Senko · 10-02-2019, 05:41 AM

^ That's great - thanks for the link to that thread.

Don't know how I missed it.

.

**UncleVanya** · 10-02-2019, 05:56 AM

Originally posted by Sandy Hancock

Ah! My bad. It was Keith, not Brad

I was very confused at first... Lol. Glad you were able to steer then to that info.

**pepperberry farm** · 10-02-2019, 05:58 AM

I sent my DA21 to Advance Camera for this repair... excellent work by them...

Senko · 10-02-2019, 06:03 AM - **1 Like**

Originally posted by pepperberry farm

I sent my DA21 to Advance Camera for this repair... excellent work by them...

How much did they charge for the repair work?

**pepperberry farm** · 10-02-2019, 06:25 AM

Originally posted by Senko

How much did they charge for the repair work?

if I remember correctly, it was about $100...

**THoog** · 10-02-2019, 06:47 AM - **1 Like**

I repaired mine using the above-mentioned forum threads, and it was surprisingly easy. I still haven't reinstalled the stick-on data / beauty ring, not trusting my own work, but it has been a couple years, so I guess I should do so.

Senko · 10-02-2019, 07:13 AM

Originally posted by THoog

I repaired mine using the above-mentioned forum threads, and it was surprisingly easy. I still haven't reinstalled the stick-on data / beauty ring, not trusting my own work, but it has been a couple years, so I guess I should do so.

Thanks for all the feedback and info, much appreciated.

Good to hear it's an easy fix, but must say I'm somewhat surprised by how many other people have experienced this exact same issue - three cases in this thread alone......

Now I'm wondering if it's a known issue with only this specific lens, or if other lenses are effected?

Can anyone else chime in on this?

ChristianRock · 10-02-2019, 01:27 PM

What kind of screw drivers do you guys purchase to do lens repair? I have 3 lenses that I got recently that need some internal cleaning.

I'll be buying some 99.99% Isopropyl Alcohol...

Kozlok · 10-02-2019, 06:13 PM - **1 Like**

Originally posted by Sandy Hancock

Ah! My bad. It was Keith, not Brad

If there is a mechanical disaster, it was usually me.

---------- Post added 10-02-19 at 07:14 PM ----------

Originally posted by Senko

Thanks for all the feedback and info, much appreciated.

Good to hear it's an easy fix, but must say I'm somewhat surprised by how many other people have experienced this exact same issue - three cases in this thread alone......

Now I'm wondering if it's a known issue with only this specific lens, or if other lenses are effected?

Can anyone else chime in on this?

My DA15 started down the same path, but I fixed it before it fell apart.

---------- Post added 10-02-19 at 07:24 PM ----------

Originally posted by ChristianRock

What kind of screw drivers do you guys purchase to do lens repair? I have 3 lenses that I got recently that need some internal cleaning.

I'll be buying some 99.99% Isopropyl Alcohol...

I just use these:

https://www.amazon.com/Stanley-66-039-Jewelers-Precision-Screwdriver/dp/B01M...ntaxforums-20&

For the record, you should be using JIS screwdrivers, but I use standard Phillips and just use axial force to prevent slipping. I'm pretty good with a screwdriver, though.

**Just1MoreDave** · 10-02-2019, 06:44 PM - **1 Like**

Originally posted by ChristianRock

What kind of screw drivers do you guys purchase to do lens repair? I have 3 lenses that I got recently that need some internal cleaning.

I'll be buying some 99.99% Isopropyl Alcohol...

I have a 4 piece JIS set from Moody's and a 4 piece JIS set from Hozan. The Hozan set has larger drivers which are not useful for lenses but has larger diameter handles and longer shafts. The long shafts are useful for long telephotos. I have gotten sets with a driver and lots of bits that include JIS bits, but that's sort of random. They rarely are labelled "JIS", more often just #00 or #0. Those sets were sold for electronics disassembly and include bits for weird Nintendo or PlayStation screws.

My opinion, you really want JIS for mount screws, and you can get by with Phillips otherwise. I saw a quotation on a boating forum, "You don't have to be prepared if you are willing to accept the consequences". That is what using Phillips bits is like. Mount screws are mostly really tight and will be deformed when you force the Phillips driver in well enough to dislodge them. Then you have to avoid noticing the damage later. The internal screws are not usually such a battle, plus all the damage is hidden.

**THoog** · 10-03-2019, 05:57 AM

Originally posted by Senko

Good to hear it's an easy fix, but must say I'm somewhat surprised by how many other people have experienced this exact same issue - three cases in this thread alone......Now I'm wondering if it's a known issue with only this specific lens, or if other lenses are effected?

The specific problem seems to be a failure of the threadlocker glue securing the three screws holding the halves of the lens together. I think any lens using this general design could be susceptible, but it appears to be rather common for earlier copies of the DA 21 Ltd. Either the factory was using a faulty product, or a bad batch of the product, or it was being applied incorrectly, or something. The issue seems to be rare or nonexistent with later copies of the lens. Since this was the Hoya-Pentax period that gave us the SDM failures, I wouldn't draw too many conclusions from it.

10-02-2019, 05:16 AM	#1
Senko Forum Member Join Date: Feb 2016 Posts: 59	SMC Pentax-DA 21mm F3.2 Limited - Is it fixable? Recently, my 21mm F3.2 Limited started experience auto focus issues out of nowhere. Worked perfectly one day, next day it wouldn't auto focus - i.e. nothing would happen when trying to focus, seems like the lens is 'locked up'. In troubleshooting the lens I tried it on 3 different bodies, cleaned the contacts, and still had the same issue. I can get it to focus sometimes by using the quick shift and focusing on something else but after a shot or two the same issue reoccurs and it locks up again. I've done a forum search and seen other people experience similar issues and even resort to disassembling the lens to fix it. My local camera repair shop does not work on Pentax and I am leery about taking the lens apart for a DIY fix. Before going this route can anyone have any other suggestions on a good resource / guide to fixing this lens myself? Thanks.

10-02-2019, 06:13 PM - 1 Like	#13
Kozlok Pentaxian Join Date: Jun 2012 Location: Albuquerque Photos: Gallery Posts: 3,148	Originally posted by Sandy Hancock Ah! My bad. It was Keith, not Brad If there is a mechanical disaster, it was usually me. ---------- Post added 10-02-19 at 07:14 PM ---------- Originally posted by Senko Thanks for all the feedback and info, much appreciated. Good to hear it's an easy fix, but must say I'm somewhat surprised by how many other people have experienced this exact same issue - three cases in this thread alone...... Now I'm wondering if it's a known issue with only this specific lens, or if other lenses are effected? Can anyone else chime in on this? My DA15 started down the same path, but I fixed it before it fell apart. ---------- Post added 10-02-19 at 07:24 PM ---------- Originally posted by ChristianRock What kind of screw drivers do you guys purchase to do lens repair? I have 3 lenses that I got recently that need some internal cleaning. I'll be buying some 99.99% Isopropyl Alcohol... I just use these: https://www.amazon.com/Stanley-66-039-Jewelers-Precision-Screwdriver/dp/B01M...ntaxforums-20& For the record, you should be using JIS screwdrivers, but I use standard Phillips and just use axial force to prevent slipping. I'm pretty good with a screwdriver, though. Last edited by Kozlok; 10-02-2019 at 06:25 PM.

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10-02-2019, 05:29 AM	#2
Sandy Hancock Moderator Site Supporter Join Date: Feb 2012 Location: Adelaide Hills, South Australia Photos: Gallery \| Albums Posts: 11,272	UncleVanya may have some some history here IIRC.

10-02-2019, 05:34 AM	#3
Kozlok Pentaxian Join Date: Jun 2012 Location: Albuquerque Photos: Gallery Posts: 3,148	My guess is it’s the start of what happened to my 21. You need to tighten the screws that hold the lens group into the lens. Mine fell completely out. Need HELP DA21 Self-Disassembled! - PentaxForums.com The only odd bit is the middle front trim ring is held on by tape, you must pry it off gently.

10-02-2019, 05:38 AM - 1 Like	#4
Sandy Hancock Moderator Site Supporter Join Date: Feb 2012 Location: Adelaide Hills, South Australia Photos: Gallery \| Albums Posts: 11,272	Originally posted by Kozlok My guess is it’s the start of what happened to my 21. You need to tighten the screws that hold the lens group into the lens. Mine fell completely out. Need HELP DA21 Self-Disassembled! - PentaxForums.com The only odd bit is the middle front trim ring is held on by tape, you must pry it off gently. Ah! My bad. It was Keith, not Brad

10-02-2019, 05:41 AM	#5
Senko Forum Member Join Date: Feb 2016 Posts: 59 Original Poster	^ That's great - thanks for the link to that thread. Don't know how I missed it. .

10-02-2019, 05:56 AM	#6
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,401	Originally posted by Sandy Hancock Ah! My bad. It was Keith, not Brad I was very confused at first... Lol. Glad you were able to steer then to that info.

10-02-2019, 05:58 AM	#7
pepperberry farm amateur dirt farmer Join Date: Dec 2014 Location: probably out in a field somewhere... Photos: Gallery \| Albums Posts: 41,660	I sent my DA21 to Advance Camera for this repair... excellent work by them...

10-02-2019, 06:03 AM - 1 Like	#8
Senko Forum Member Join Date: Feb 2016 Posts: 59 Original Poster	Originally posted by pepperberry farm I sent my DA21 to Advance Camera for this repair... excellent work by them... How much did they charge for the repair work?

10-02-2019, 06:25 AM	#9
pepperberry farm amateur dirt farmer Join Date: Dec 2014 Location: probably out in a field somewhere... Photos: Gallery \| Albums Posts: 41,660	Originally posted by Senko How much did they charge for the repair work? if I remember correctly, it was about $100...

10-02-2019, 06:47 AM - 1 Like	#10
THoog Loyal Site Supporter Join Date: Aug 2012 Location: North Carolina Photos: Gallery \| Albums Posts: 3,685	I repaired mine using the above-mentioned forum threads, and it was surprisingly easy. I still haven't reinstalled the stick-on data / beauty ring, not trusting my own work, but it has been a couple years, so I guess I should do so.

10-02-2019, 07:13 AM	#11
Senko Forum Member Join Date: Feb 2016 Posts: 59 Original Poster	Originally posted by THoog I repaired mine using the above-mentioned forum threads, and it was surprisingly easy. I still haven't reinstalled the stick-on data / beauty ring, not trusting my own work, but it has been a couple years, so I guess I should do so. Thanks for all the feedback and info, much appreciated. Good to hear it's an easy fix, but must say I'm somewhat surprised by how many other people have experienced this exact same issue - three cases in this thread alone...... Now I'm wondering if it's a known issue with only this specific lens, or if other lenses are effected? Can anyone else chime in on this?

10-02-2019, 01:27 PM	#12
ChristianRock Pentaxian Join Date: Jul 2013 Location: People's Republic of America Photos: Gallery \| Albums Posts: 9,910	What kind of screw drivers do you guys purchase to do lens repair? I have 3 lenses that I got recently that need some internal cleaning. I'll be buying some 99.99% Isopropyl Alcohol...

10-02-2019, 06:44 PM - 1 Like	#14
Just1MoreDave Site Supporter Join Date: Feb 2007 Location: Aurora, CO Photos: Gallery \| Albums Posts: 6,340	Originally posted by ChristianRock What kind of screw drivers do you guys purchase to do lens repair? I have 3 lenses that I got recently that need some internal cleaning. I'll be buying some 99.99% Isopropyl Alcohol... I have a 4 piece JIS set from Moody's and a 4 piece JIS set from Hozan. The Hozan set has larger drivers which are not useful for lenses but has larger diameter handles and longer shafts. The long shafts are useful for long telephotos. I have gotten sets with a driver and lots of bits that include JIS bits, but that's sort of random. They rarely are labelled "JIS", more often just #00 or #0. Those sets were sold for electronics disassembly and include bits for weird Nintendo or PlayStation screws. My opinion, you really want JIS for mount screws, and you can get by with Phillips otherwise. I saw a quotation on a boating forum, "You don't have to be prepared if you are willing to accept the consequences". That is what using Phillips bits is like. Mount screws are mostly really tight and will be deformed when you force the Phillips driver in well enough to dislodge them. Then you have to avoid noticing the damage later. The internal screws are not usually such a battle, plus all the damage is hidden.

10-03-2019, 05:57 AM	#15
THoog Loyal Site Supporter Join Date: Aug 2012 Location: North Carolina Photos: Gallery \| Albums Posts: 3,685	Originally posted by Senko Good to hear it's an easy fix, but must say I'm somewhat surprised by how many other people have experienced this exact same issue - three cases in this thread alone......Now I'm wondering if it's a known issue with only this specific lens, or if other lenses are effected? The specific problem seems to be a failure of the threadlocker glue securing the three screws holding the halves of the lens together. I think any lens using this general design could be susceptible, but it appears to be rather common for earlier copies of the DA 21 Ltd. Either the factory was using a faulty product, or a bad batch of the product, or it was being applied incorrectly, or something. The issue seems to be rare or nonexistent with later copies of the lens. Since this was the Hoya-Pentax period that gave us the SDM failures, I wouldn't draw too many conclusions from it.