Cleaning lens contacts

Discussion in 'Canon EOS' started by scorch, Oct 12, 2008.

  1. What would be the best way to go about cleaning the lens contacts on both my lens and my 50D? I've gotten Err99 a
    couple of times, but I've heard a lot of times cleaning the lens contacts can fix it, so I thought I would give
    it a try. Thanks!
  2. Use a pencil eraser - works best!
  3. Cloth with ethanol.
  4. I use Caig DeoxIT, a product designed specifically for de-oxidizing electrical contacts. Caig products can be purchased directly from Caig at, of from one of their many retail distributors. Check the "Distributor Info" tab on their web site.
  5. Any alcohol pad will do the job (ie: Vodka on a T-shirt). Sandpaper will do a better job then pencil eraser :) aka: Use eraser only as last resource as it can take away a bit of gold finish and make matter worst later on. . Also, sometime the pins on the camera body get gum up too.
  6. Another vote for the eraser. No need to mess with anything else. It is also the first suggestion made by Canon's tech people.
  7. Pencil erasers, esp the ones on the end of a pencil are really good at removing the microscopically thin gold coating on the pins, that way you will be buying new hardware or getting it repaired sooner than later. They are very abrasive. Now a Pink Pearl or similar art gum one is much better to use, if you have to use an abrasive.

    Otherwise alcohol or lighter fluid on a cotton swab is a much better choice, and won't leave abrasive laden rubber bits floating around inside your camera or on the back of the lens.
  8. Bob, if the person is using the eraser so firmly that it leaves rubber bits, they are using it too firmly. A few light swipes that leave no residue and do not damage the contacts is all that it takes. This is a very occasional operation. I don't think that any lens of mine has needed it more than once.
  9. I generally use isopropyl (rubbing) alcohol on a clean cloth. If you look at most "electronic contact" cleaners,
    you'll find they are simply isopropynol and purified water... exactly the same as "rubbing alcohol", but about
    20X or 30X the price.

    For use on location, I have a package of "wipettes" pre-moistened with isopropynol. These are actually for
    computer keyboard and similar cleaning, but work fine on cameras and their contacts, too. They cost more, about
    $10 for a pack of 70 or 80, if I recall correctly, but they are more convenient that taking a bottle of rubbing
    alcohol along.

    I won't use pencil erasers and am a bit surprised Canon recommends it on their website.

    Erasers are made with vegetable oil. What's often the problem on those contacts is a very light coating of oil
    (finger oils, manufacturing oils, etc.) inturrupting the tiny electrical flow. The last thing I want to do is rub
    something made from oil onto the surface, possibly leaving some more residue! (Ever notice how sometimes a pen
    won't write over an area that's been erased?)

    There's also the concern Bob mentioned, that any grit in the eraser might actually do damage to the coatings on
    the contacts. Finally, I really don't like risking getting any pieces of eraser falling down into the camera.

    DeOxit is a very good product, but probably overkill for this situation. Oxidization is usually not a problem,
    the contacts are gold-plated specifically for that reason (gold does not oxidize).

    Never *ever* use a cotton swab (Q-Tip) anywhere inside a camera. Very risky! This is one of the first thing
    camera repair techs are taught. Common cotton swabs shed tiny cotton fibers that can completely jam shutter and
    other mechanisms and you can easily end up with some expensive repair bills.

    The only exception would be swabs specifically made for optical cleaning, which do not shed fibers (most aren't
    "spun" cotton, anyway).

    In addition to cleaning the lens-to-camera contacts, make sure you have the latest firmware installed and watch
    for any firmware updates. Err 99 is sort of a "catch all" error code and there could be something entirely
    unrelated to the lens-to-camera contacts going on, that will be addressed in future firmware revisions.
  10. First approach: Rub/polish firmly with a microfiber cloth.

    If that doesn't work, moisten the cloth very lightly with denatured alcohol (with no water content) -- not enough to drip. Rub again. (You don't want fluids, especially water, wicking into the camera or lens.)

    If you feel you have to use an eraser, at least use a gum eraser that has been pre-cleaned with alcohol, and don't rub hard enough to shed any rubber. But I wouldn't recommend it.

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