zoom problem - solved (DIY)

[Cosmin Rotaru]

A while ago I was hit by this problem (as David Woodland described it best):
"every now and then when I zoom in using the zoom grip, not the handle, it will either keep zooming and zooming when i let go of it.. or it will zoom in super slow"
If you don't know what I'm talking about, you can read this:

http://www.dvinfo.net/conf/showthrea...threadid=14341

As my guranty expired and I don't have Canon service center near by, I figure I could try solving the problem my self. And I did.

So, if you have a good, steady hand (and an out of guaranty canon xm2/gl2), you can follow a few simple steps and repair your sticky zoom. :)

First: remove the plastic cover from the tape compartment. This is held by two screws:
one in front of the cover http://w1.226.telia.com/~u22607422/1 FrontScrew.jpg and one at the back http://w1.226.telia.com/~u22607422/2 BackScrew.jpg

BEFORE removing the cover, notice the two pins that holds the plastic cover in the lower part. You need to remember where these goes, so you can put the cover back when you're finish!
http://w1.226.telia.com/~u22607422/3 UnderPin.jpg
http://w1.226.telia.com/~u22607422/4 InsidePin.jpg

Now that you unscrewed the two screws at the top of the plastic cover, you just lift this cover up and expose the guts of the tape compartment door!

http://w1.226.telia.com/~u22607422/5 PullUp.jpg

Now, for the most difficult part, you need to remove the zoom lever. You'll notice that it has two ears on which it pivots. Use two very small screwdrivers to drag the ears over the litle pins on which they ride. First I tried to drag one ear at a time - no luck that way. I had to work both ears at the same time. I aged like 10 years doing this! The ears are very small and fragile. So take care! (I was about to give up at this stage...)

http://w1.226.telia.com/~u22607422/6 ZoomEar.jpg

Ok, you managed to remove the zoom lever? You found it where it jumped? :) (don't worry, it has no spring or anything else underneath that could be lost. This was hard!

Now, what you have to do is to clean the contacts (with "contact spray") of the zoom lever
http://w1.226.telia.com/~u22607422/7 ZoomContacts.jpg
and the actual potentiometer that makes the zoom
http://w1.226.telia.com/~u22607422/8 Pot.jpg
You can actualy see the dirt or watever is on the pic above. Don't rub the contacts to hard. Use contact spray. Don't use sandpaper or any other abrasive! Just contact spray that states it's good to clear contacts and potentiometers.

You finished cleaning the pot? Now put the lever back (it goes easy - it does "click") and plastic cover. You're done! :)

I have to tell you that this problem will return. As I saw how this zoom is design, I imagine all users will have this problem sooner or later. You see, a good potentiometer is sealed from outsied dust/water and watever. This is not! This is very much exposed to humidity and it will develop oxides over time. I also can't imagine how many times this pot can be cleaned before you don't have what to clean anymore...

Well.... good luck! :)

[Graham Bernard]

Cosmin, well, I don't know if I will get around to it .. or I'll get Canon to do it for me . . BUT:

1 - THANK you very much for all your efforts - you excellent MAN!

2 - The presentation was simplicity itself to understand.

3 - Your explanations - as far as I know - would seem to be very straight forward.

.. the only thing I'm a little "weak" about are the the 2 pins and easing the lever over them?

Anyways, I now have amunition to take to Canon and say "Get on with it!"

Thanks again . .. I'm printing it off as I type this .. .

Grazie

[Cosmin Rotaru]

No problem!
I hope this would help some users, as this is something many experienced or WILL experience. It is so obvious by the play the lever has, that is very easy to contaminate the interior of the zoom...

"the only thing I'm a little "weak" about are the the 2 pins"

Take a look at this pic again:
http://w1.226.telia.com/~u22607422/7 ZoomContacts.jpg You can better see the ears and the scratches I made on the zoom lever while trying to remove it...
I want to emphasize again that you should really pay attention at this stage! If you're not sure you can do it, ask someone else you can trust with the job!

[Graham Bernard]

Oh, I think I see . .you are actually needing to "prize" apart . . VERY slightly the "legs" of the rocker so that it slips/un-clips away from the sationary "pivots" .. which are part of the main body .. yes .. this is VERY tiny indeed! Can't be more than 10mm between your fingers? The thickness of the Rocker? I can quite clearly see the scratches and can imagine what you must have been thinking! . . . Tell, how on Earth diod you think that it would be this . . er .. easy? Perhaps not easy .. . but rather straight forward?

Grazie

[Robin Davies-Rollinson]

Cosmin,

Thanks for taking the trouble to post those pictures.
If my camera should develop this trouble, I'll be following your excellent instructions to the letter!

Robin.

[Cosmin Rotaru]

You can also see that English is not my native language! :) So thanks for the comment, Graham! ("prize" appart that is:) ).

Robin, I hope you'll never see this problem on your camcorder. I remember an waiter tipped a champagne glass on the table were I left my XM2 (don't ask me why my camcorder was there) and a few drops (luckly just that) went on the zoom lever... I'm not sure that the drop went inside. Anyway, greasy - salty - vapors from your fingers will sure get in there! The damn thing is not protected at all from outside elements! :(

[Hans Nyberg]

Well I disassembled the zoom switch (twice). Using Cosmin's pics and directions, it was actually pretty easy. But I came to a different conclusion to what the the problem is.

Cleaning the contacts didn't make any difference, but it looked to me like the contacts inside the rocker didn't have enough tension on them to make a good connection with the potentiometer. To test my theory I inserted a "shim" on the outside (right side if you're looking at the back of the camera) of the rocker switch. This pushes the switch toward the potentiometer.

Now, for the first time in months, the zoom works perfectly. Not exactly a permanent fix but if Canon has an improved zoom lever maybe they could supply it to the people who would like to make their own repair.

Hans

[Alan Craven]

This sounds like an internal solution which has the same effect as the external solution I posted last October, here:

http://www.dvinfo.net/conf/showthrea...5&pagenumber=1

Unfortunately it did not last, and I ended up having to pay for a complete new cassette door assembly. I was told that the problem was due to the ribbon cable failing at the point where it emerged from the switch.

[Graham Bernard]

Hans, I was thinking this. Sometime back one of our friends here did a similar thing with a small cable tie - think I've got it correct . .. hold on I'll attempt to find the link .. brb . .. .

. . . here yah go! http://www.dvinfo.net/conf/showthrea...cable+tie+zoom

But, in the end, it just stops again.

This, IMHO, is a sad state of affairs. I've been applying some small engineering/electronic/electrical knowledge I do have. I've come up with the following.

It is requesting that "tension" or pressure remain positive in a plane that is at right angles to the "movement" - the need to "sweep" the radius of the pot - without the same downward pressure that is being applied by the fingers on the Rocker Arm. Not good. There isn't any positive downward application of the transference of the the fingers pushing the zoom rocker down to make this positive contact. The positive sweeping contact is solely reliant on the residual, factory set "Springiness" of the very tiny pot brushes. IMHO, again, the sweeper is needing to do 2 things. Firstly: to keep contact - remain ON and on the plates. Secondly to have enough positive pressure to obviate any "dry" contact that might have been created by dirt or grease form the exterior. Again, any "relaxing" in the tension created by the factory set of the springiness will, over time, exacerbate a problem. As the sweeper brushes and receives the current and in turn might encounter a small resistance they could will momentarily have a tiny increase in temperature. This in turn , IMHO, could affect the default "spring" in the sweepers. As we know heat can reduce the spring in metals. Could this be a factor?

So, friends we might be observing several effects:

1 - A gradual reduction in Zoom Rocker control - This I've got.

2 - An improvement by inserting a "shim" in the place described - this fits too with what I've outlined.

3 - Cleaning and reset makes for improvement - Cosmin

4 - Presently there is no protection to detritus making its way into the area under consideration.


I'd like to know from Canon is:

1 - IF this Zoom setup is different from that which was present in the GL1/XM1?

2 - Is it different from the XL1/XL1s or come to that the new XL2 [ Chris can you take it apart ??!?!? ]

3 - IF Canon has changed the design, has it been done to "improve" an issue previously encountered? And what was that problem?

4 - Have "others" any knowledge of how other Zoom/Rocker combinations are executed on say Sonys or Panasonics?

So, where do we go from here? A real solution would be neat! And maybe some recognition that there maybe JUST maybe an issue does exsist . . . . Would I still buy another XM2 - Yah Betcha!

Best regards,

Grazie

[Graham Bernard]

Alan? How effective has it been so far? - I'm presuming it has fixed the issue? What do you think of my outline?

Grazie

[Alan Craven]

Graham,

As I said in my post above, my jury rig with the cable tie merely delayed the inevitable. It did (just) survive my New Zealand trip, but by the end it was an absolute pain.

It is possible that I was told the truth, and the fault in my case was a cable fault, but having read Cosmin's post, I am very doubtful. I suspect I was ripped off, but then, servicing these days does basically mean replacing faulty modules with new.

My camera is an XM1, so it seems that the design fault - for this is clearly what it is - exists in both XM1 and XM2 models.

Your analysis seems reasonable. For my sins, I used to teach electronic engineering, so I have some knowledge in this area. The most common piece of equipment with a sprung blade wiping a track is the humble volume control. These regularly fail due to any permutation of track wear/dirt/weakening of spring contact. Once the contact becomes impaired, as you note, resistance increases, heat is generated and the problem is exacerbated.

The old aerosol switch cleaner could often save the day here! If I ever have the problem again, I shall try Cosmin's technique, but use some high tech gold based contact goo used in Hi Fi. I have converted his post and photographs to a Word document for future reference!

I have had exactly the same problem in the past with a Nikon 35mm SLR where the track contact failed on the aperture control ring in the camera body lens mount. There were two major differences between the Nikon and the Canon though: cost - Nikon far less than Canon; availability of part - Nikon immediate, Canon,only after several weeks!

[David Woodland]

My zoom won't even work now. The handle zoom and grip zoom are both messed up. Every now and then it will zoom somehow though. This makes it impossible to shoot with the camera so I guess I need to send it somewhere... I still have a 3 yr warranty left. Also, will they be able to fix this problem for good?

[Cosmin Rotaru]

The problem returned, even worse...
The cleaning stuff made it work for some time but now it just works now and then. Sometime I can press zoom in/out with no response from the camcorder. I also got another reaction: zoom in and the camera would not stop zooming in. I tried pushing zoom out breafly as to stop it from zooming in, and then i couldn't stop it from zooming out... I did this "effect" many times, like a crazy dude that just discovered the zoom... The enitre shoot was compromise. :(

[Robin Davies-Rollinson]

Exactly the same thing has just happened with my XM2. At least, I can use the control on the handle as well as the LANC remote. However, it will have to be returned to Canon ...

Robin

[Graham Bernard]

Cosmin & Robin, I took my XM2 to Canon in Herts - here in the UK - and a chap said he had not heard of the problem.

Robin, what are you intending to do? I think this is an awful failure on what is a remarkable camcorder. I think Canon INC should be mnade aware of this. My Father - 86 bless! - has an ancient Panasonic PAL annie . . kinda Pannie Annie PALlie - and the zoom works just as well now as it did in 1986 . .. 18 years? I/we have had our XM2's for what . . 1 to 2 years and this is what is happening?

I am not very happy at all. I'm now in the position of needing to buy another camcorder, just so I can 1/- Be assured I've got back up and 2/- Have an opportunity to get my zoom failing XM2 into the Canon Garage . ..

Graham Bernard