RiceHigh's Pentax Blog: DIY Again: Disassemble (and Repair) a DA* 50-135!

Sunday, January 02, 2011

DIY Again: Disassemble (and Repair) a DA* 50-135!

A Hong Kong DA*50-135 lens owner found that his lens always mis-focused in the range between 80mm to 135mm, so he decided to disassemble it and saw if he could repair it..

See:-

http://www.facebook.com/album.php?aid=268652&id=755984264&l=23d0a5f29b

To see the large pictures you're interested in, just click the respective thumbnail to enlarge.

After the disassembly, he found that the electronic contacts in a metal brush form, which is part of the zooming mechanism, was distorted and thus causing bad contact, which should be the evil for causing the AF issue. He then reshaped the brush and then reassembled the whole lens, now everything is working normally! Brilliant, guy! You're really a great repair technician yourself! :-D My hat off! Possibly the local Pentax service centre couldn't trouble-shoot this problem for you straight-forwardly! :-( So, DIY is always great, provided that you know what to do yourself! :-)

To view from start for all large pictures one by one, you can visit:-

http://www.facebook.com/photo.php?pid=5707657&id=755984264&l=23d0a5f29b

Read Also:-

Disassemble a DAL 18-55

Comments (6)

Logging you in...

Dashboard | Edit profile | Logout

Logged in as

+1 Vote up Vote down

Andy · 740 weeks ago

Interesting , But I've seen that damage before its caused by lifting the barrel without removing the fingers first..
i.e the dismantler did this damage during dissasemly.
The easiest way to check the fingers is lift the rubber grips and unscrew.

+1 Vote up Vote down

Indepat · 571 weeks ago

Recently, I have been the same trouble after DIYing for SDM stuck problem. These solutions are very useful to correct the electronic contacts of finger type. It was easy to reshape the fingers by taking off the rubber grip only and unscrewing the fingers without disassembling the whole lens. Thanks much to Ricehigh, Kenneth, and Andy.

0 Vote up Vote down

Kenneth · 429 weeks ago

Thanks you guys' comment !

I just want to say this lens was bought from a local Pentax user in Hong Kong second hand market and he had mentioned to me that the lens has the SDM and focusing problem and sold it to me very cheap in cost and asked me to use it as a manual focus * lens !

Perhaps the fingers problem was caused by the previous owner who try to repair the SDM problem by himself before he sold this to me.

Of course, Andy's suggestion is the right and easiest way to check and fix the contact pins of under the zoom ring and finally I realized that and mentioned in my FB page about this point. Also, this lens now have been disabled the SDM function which I modified the lens firmware already and using the camera body's drive motor for focusing happily !