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Hardware diagnostics

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Offline ahull

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Re: Hardware diagnostics
« Reply #10 on: 04 / September / 2014, 14:22:20 »
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Well, it seems I've found the problem. The focus lens has a threaded brass insert which engages with the focusing leadscrew, and the thread in the brass  is worn out, with the result that the focus motor is unable to move the focus lens against the retaining spring. So unless I could find a friendly amateur watch maker to make me a new brass thingy or a camera with a different fatal error to cannibalise, this would seem to be the end of the road. And I can put off the vexing question of which colour nail varnish to get  ;)

Thank you for suggestions, one and all. I've leant a lot.

Regards - Philip

Ah.. it sounds like the thread has been stripped from the screw, possibly by dropping the camera in such a way as to damage the thread. It looks like a replacement lens unit is the only way forward, unless, as you say, you can find someone to machine you a replacement insert. Well, you win some, and loose some. I have a small collection of lens units which are beyond repair. Sadly since none are from an SX200, they  would be unlikely to yield the part you need.

... unless you can fill the brass insert hole with something suitable to allow you to re-thread it with the leadscrew... but that sounds like its going to be more trouble than it is worth.
« Last Edit: 04 / September / 2014, 14:26:16 by ahull »

Re: Hardware diagnostics
« Reply #11 on: 04 / September / 2014, 14:52:44 »
I have an SX 200 with damaged objective, too. It can not focus properly, not every time but most of time. It can be seen with CHDK, so I can use it for shooting photos.
Actually, I have seen how to replace the objective, and that is not for beginners. So, I do not know that it will be ever replaced, but maybe a software fix will do it. So I am curious about every new things in CHDK. :)
(A 410), SX 200, (SX 280), SX 700

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Offline ahull

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Re: Hardware diagnostics
« Reply #12 on: 04 / September / 2014, 15:10:58 »
I just watched that lens replacement video, it looks relatively painless, so long as you take care to put the screws back in the holes they came from.

Some cameras require quite a bit more surgery, including the un-soldering of various wires to replace the lens.

The SX200 looks quite large by comparison to say the iZoom or the SD430 Ixus Wireless. Smaller camera usually means smaller connectors, so much more fiddly. Older cameras like the Powershot A560 and Ixus 60 are probably the easiest to work on.

Re: Hardware diagnostics
« Reply #13 on: 04 / September / 2014, 16:12:21 »
I started with that video, but having dismantled and reassembled it at least 4 or 5 times now, I put everything I've learnt except the latest about dismantling the lens in a fixit guide at https://www.ifixit.com/Guide/Disassembling+Canon+PowerShot+SX200+IS/28471. Hopefully that should be easier than the video as you can take it at your own pace - and it's in English. Replacing the lens as a unit is quite easy - go for it Mastodon, then click the "I did it" button on the bottom to give me some reputation! It sounds, though, as if you may have the same problem as me but not yet quite so severe. If so, you might find that the camera orientation (upside down, portrait either way, facing the floor, facing the sky) makes the focussing problem slightly worse or slightly better. The camera I'm working on has been quite heavily used (many thousands of exposures over 4 years) so I suspect the thread in the brass insert is simply worn out.


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Offline ahull

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Re: Hardware diagnostics
« Reply #14 on: 04 / September / 2014, 16:31:46 »
The fixit guide looks good to me, but the link in your post above has an un-needed  "." at the end.

It should of course be...

https://www.ifixit.com/Guide/Disassembling+Canon+PowerShot+SX200+IS/28471

.. they say a picture is worth a thousand words...  :D

 

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