Need HELP DA21 Self-Disassembled!

Kozlok · 01-20-2014, 08:23 PM

OK, my DA21 completely self disassembled! There are 3 screws that hold the lens group in the body of the lens, and they all fell out. It should be easy to fix, but it requires removing the front trim ring. I've tried several ways to remove the front trim ring, to no avail. Any suggestions? Is it the part with the words that comes off or the center part?

Thanks!

**seventhdr** · 01-20-2014, 09:12 PM

I found some information here:

RiceHigh's Pentax Blog: Disassemble the DA21 Limited (and the Secret of the QSF Mechanism)

Follow the link on this page for more information.

There is also a database of repairs on Pentax Forums;

https://www.pentaxforums.com/forums/114-maintenance-repair-articles/179884-pe...-database.html

Hope this helps

Regards

Chris

JinDesu · 01-20-2014, 09:28 PM

Center part. I got it off using a eyeglass flathead screwdriver - but it's tight enough where you might bend that kind of screwdriver. It's held in with 3 pieces of double-sided tape.

https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/121842-prob...-infinity.html

This thread has a lot of info regarding your issue.

LFLee · 01-20-2014, 09:32 PM

in case you don't understand Chinese, the important part is here:

You have to remove the 'ring' that contain the letters, screws are hidden there.

JinDesu · 01-20-2014, 09:35 PM

Er not quite - you can't get to the letter ring without taking off the center circle part that sticks out.

It exposes 3 screws:

Which is the name plate, and if you take that off you get to the 3 screws that hold the focus ring.

Kozlok · 01-20-2014, 09:40 PM

Thanks All! Maybe I can get my beloved back up and running tomorrow night.

Kozlok · 01-20-2014, 09:42 PM

Originally posted by JinDesu

Er not quite - you can't get to the letter ring without taking off the center circle part that sticks out.

It exposes 3 screws:

Which is the name plate, and if you take that off you get to the 3 screws that hold the focus ring.

Err...HOW do I get the center bit out?

JinDesu · 01-20-2014, 10:04 PM

Originally posted by Kozlok

Err...HOW do I get the center bit out?

As I said, I used a eyeglass flathead screwdriver. It did a little bit of scratching to the body, but that's because I was a little careless. You just put it between the center and the body and you angle off.

Kozlok · 01-21-2014, 05:27 PM

Originally posted by JinDesu

As I said, I used a eyeglass flathead screwdriver. It did a little bit of scratching to the body, but that's because I was a little careless. You just put it between the center and the body and you angle off.

Sorry! Missed the first time you posted that in my absolute panic. I'm calmer now. I shall attempt repairs now...

JinDesu · 01-21-2014, 06:27 PM

Originally posted by Kozlok

Sorry! Missed the first time you posted that in my absolute panic. I'm calmer now. I shall attempt repairs now...

No problem - try to get a good thin flathead and wedge it in and make sure it's caught before levering it off. I find that levering it slowly to loosen it at a few different spots is the best result without damaging anything.

Also, to repair it - make sure you get threadlock or something. It can be tricky to apply (I rolled the little screws in the threadlock compound, then gently dropped it into their slots), but without threadlock they will come loose again.

And lastly - DO NOT TAKE OUT THE LENS FROM THE CASING. That center bit with the glass, do NOT take that out. I did and I damaged a little metal brush thing and now my lens won't AF anymore.

Kozlok · 01-21-2014, 07:14 PM

WOO WOO!!!! Crisis averted. In my original attempts to disassemble the lens, I went way too far, and I had some trouble getting everything back together. I had to disassemble the whole thing to get it back right. Of course I spun the focusing gear round and round and got it completely out of its original plane. I'll have to check infinity when there's light.

At one point, I mangled the little electrical fingers that run around inside the focus gears, but I managed to get them adjusted more or less straight and true. Does anyone know what information those fingers regulate? Maybe focus distance? Any ideas how I'd check that the data was transmitting correctly? The exif seems intact, but I'm worried it might affect SR or something like that.

Here's a shot post-repair of my 35 Macro. Focus on the 5, hit it spot on!

JinDesu · 01-21-2014, 07:16 PM

Those little finger things relay info regarding AF. Without them, the lens won't focus.

Kozlok · 01-21-2014, 08:04 PM

Originally posted by JinDesu

Those little finger things relay info regarding AF. Without them, the lens won't focus.

Thank you so much. It focuses perfectly fine, so I guess all is well. I owe you dinner or something!

JinDesu · 01-21-2014, 08:34 PM

Hah, no problem

Edgar_in_Indy · 01-23-2014, 05:52 AM

Mental note to self: Remember to never buy a 21mm from Kozlok

Ha ha, just kidding, nice job! It's always a good feeling when you can repair something yourself that would have been expensive to have somebody else do it. Especially when it's a job that takes you outside your comfort zone.

You probably just saved yourself a couple hundred bucks, which is really the same as making a couple hundred bucks. So you would now be completely justified in going out and spending $200 on something else you would like. (At least that's what I told my wife yesterday when I spent a couple hours under the dash of her minivan and discovered that the problem with the heater fan not working on most settings was just a loose connection to the blower motor resistor).

01-20-2014, 08:23 PM	#1
Kozlok Pentaxian Join Date: Jun 2012 Location: Albuquerque Photos: Gallery Posts: 3,148	Need HELP DA21 Self-Disassembled! OK, my DA21 completely self disassembled! There are 3 screws that hold the lens group in the body of the lens, and they all fell out. It should be easy to fix, but it requires removing the front trim ring. I've tried several ways to remove the front trim ring, to no avail. Any suggestions? Is it the part with the words that comes off or the center part? Thanks!

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01-20-2014, 09:12 PM	#2
seventhdr Site Supporter Join Date: Mar 2007 Location: Christchurch, New Zealand Photos: Gallery Posts: 1,443	I found some information here: RiceHigh's Pentax Blog: Disassemble the DA21 Limited (and the Secret of the QSF Mechanism) Follow the link on this page for more information. There is also a database of repairs on Pentax Forums; https://www.pentaxforums.com/forums/114-maintenance-repair-articles/179884-pe...-database.html Hope this helps Regards Chris

01-20-2014, 09:28 PM	#3
JinDesu Veteran Member Join Date: Jun 2011 Location: New York City Photos: Gallery Posts: 5,638	Center part. I got it off using a eyeglass flathead screwdriver - but it's tight enough where you might bend that kind of screwdriver. It's held in with 3 pieces of double-sided tape. https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/121842-prob...-infinity.html This thread has a lot of info regarding your issue.

01-20-2014, 09:32 PM	#4
LFLee Veteran Member Join Date: Aug 2009 Location: Southern California Photos: Gallery \| Albums Posts: 2,292	in case you don't understand Chinese, the important part is here: You have to remove the 'ring' that contain the letters, screws are hidden there.

01-20-2014, 09:35 PM	#5
JinDesu Veteran Member Join Date: Jun 2011 Location: New York City Photos: Gallery Posts: 5,638	Er not quite - you can't get to the letter ring without taking off the center circle part that sticks out. It exposes 3 screws: Which is the name plate, and if you take that off you get to the 3 screws that hold the focus ring.

01-20-2014, 09:40 PM	#6
Kozlok Pentaxian Join Date: Jun 2012 Location: Albuquerque Photos: Gallery Posts: 3,148 Original Poster	Thanks All! Maybe I can get my beloved back up and running tomorrow night.

01-20-2014, 09:42 PM	#7
Kozlok Pentaxian Join Date: Jun 2012 Location: Albuquerque Photos: Gallery Posts: 3,148 Original Poster	Originally posted by JinDesu Er not quite - you can't get to the letter ring without taking off the center circle part that sticks out. It exposes 3 screws: Which is the name plate, and if you take that off you get to the 3 screws that hold the focus ring. Err...HOW do I get the center bit out?

01-20-2014, 10:04 PM	#8
JinDesu Veteran Member Join Date: Jun 2011 Location: New York City Photos: Gallery Posts: 5,638	Originally posted by Kozlok Err...HOW do I get the center bit out? As I said, I used a eyeglass flathead screwdriver. It did a little bit of scratching to the body, but that's because I was a little careless. You just put it between the center and the body and you angle off.

01-21-2014, 05:27 PM	#9
Kozlok Pentaxian Join Date: Jun 2012 Location: Albuquerque Photos: Gallery Posts: 3,148 Original Poster	Originally posted by JinDesu As I said, I used a eyeglass flathead screwdriver. It did a little bit of scratching to the body, but that's because I was a little careless. You just put it between the center and the body and you angle off. Sorry! Missed the first time you posted that in my absolute panic. I'm calmer now. I shall attempt repairs now...

01-21-2014, 06:27 PM	#10
JinDesu Veteran Member Join Date: Jun 2011 Location: New York City Photos: Gallery Posts: 5,638	Originally posted by Kozlok Sorry! Missed the first time you posted that in my absolute panic. I'm calmer now. I shall attempt repairs now... No problem - try to get a good thin flathead and wedge it in and make sure it's caught before levering it off. I find that levering it slowly to loosen it at a few different spots is the best result without damaging anything. Also, to repair it - make sure you get threadlock or something. It can be tricky to apply (I rolled the little screws in the threadlock compound, then gently dropped it into their slots), but without threadlock they will come loose again. And lastly - DO NOT TAKE OUT THE LENS FROM THE CASING. That center bit with the glass, do NOT take that out. I did and I damaged a little metal brush thing and now my lens won't AF anymore.

01-21-2014, 07:14 PM	#11
Kozlok Pentaxian Join Date: Jun 2012 Location: Albuquerque Photos: Gallery Posts: 3,148 Original Poster	WOO WOO!!!! Crisis averted. In my original attempts to disassemble the lens, I went way too far, and I had some trouble getting everything back together. I had to disassemble the whole thing to get it back right. Of course I spun the focusing gear round and round and got it completely out of its original plane. I'll have to check infinity when there's light. At one point, I mangled the little electrical fingers that run around inside the focus gears, but I managed to get them adjusted more or less straight and true. Does anyone know what information those fingers regulate? Maybe focus distance? Any ideas how I'd check that the data was transmitting correctly? The exif seems intact, but I'm worried it might affect SR or something like that. Here's a shot post-repair of my 35 Macro. Focus on the 5, hit it spot on!

01-21-2014, 07:16 PM	#12
JinDesu Veteran Member Join Date: Jun 2011 Location: New York City Photos: Gallery Posts: 5,638	Those little finger things relay info regarding AF. Without them, the lens won't focus.

01-21-2014, 08:04 PM	#13
Kozlok Pentaxian Join Date: Jun 2012 Location: Albuquerque Photos: Gallery Posts: 3,148 Original Poster	Originally posted by JinDesu Those little finger things relay info regarding AF. Without them, the lens won't focus. Thank you so much. It focuses perfectly fine, so I guess all is well. I owe you dinner or something!

01-21-2014, 08:34 PM	#14
JinDesu Veteran Member Join Date: Jun 2011 Location: New York City Photos: Gallery Posts: 5,638	Hah, no problem

01-23-2014, 05:52 AM	#15
Edgar_in_Indy Veteran Member Join Date: May 2010 Location: Indiana, USA Photos: Gallery Posts: 2,685	Mental note to self: Remember to never buy a 21mm from Kozlok Ha ha, just kidding, nice job! It's always a good feeling when you can repair something yourself that would have been expensive to have somebody else do it. Especially when it's a job that takes you outside your comfort zone. You probably just saved yourself a couple hundred bucks, which is really the same as making a couple hundred bucks. So you would now be completely justified in going out and spending $200 on something else you would like. (At least that's what I told my wife yesterday when I spent a couple hours under the dash of her minivan and discovered that the problem with the heater fan not working on most settings was just a loose connection to the blower motor resistor).