I have a very irritating issue with my Canon 40D bought only two years ago: the shutter release is working only 1 times over 4 tries. After some google searches I found this solution: pour one spoon of isopropyl alcohol in the battery compartment while keeping the camera up-side down and pressing the shutter release a few times, then wait until alcohol is completely evaporated.

My question is: is this method safe, reliable and useful?

I have been able to find only answers about external use of alcohol, but not internal.

My secondary questions are: if it works, how come? Is the liquid just flowing through the mechanism and then enters in contact with the dirty pieces? What kind of dirt lies at the origin of this issue, and most importantly how can I avoid this to happen again?

  • 2
    \$\begingroup\$ Sounds like a recipe for disaster. How about sending it for repair? Shutter-release replacement should be not very costly. \$\endgroup\$
    – Itai
    Jun 22, 2013 at 22:34
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    – Dilaton
    Apr 2, 2014 at 20:22

3 Answers 3


Don't bother. I agree with Itai's comment. In questions like this it's hard to commit to yes or no since one is so unsure of what is actually broken. It could work after you treat it, but the risk vastly outweighs the benefit. 25% function is still better than 0%, and the only way you can be sure it won't be further broken (or might even get fixed!) is by handing it over to Canon to fix.

Alcohol can be used to clean lenses and screens, but any liquid (including water or high purity alcohol) on the inside has a risk of not evaporating properly, or moving the dirt somewhere worse.

The most risky fix/clean I have tried myself was I had somehow got some residue on my sensor. I have the bennefit of working in a lab with access to Milli-Q water. A dab (2µL) of this onto the dirt on the sensor followed by 5 minutes in a drying cupboard at 40˚C did the job.


I sprayed electrical contact cleaner into the shutter button while holding the camera upside down. The cleaner dripped right back out of the button. I could see plenty of "stuff", probably flakes of skin, when contact cleaner dribbled out. Bought my 40D used as a backup, and after a couple sprays of electrical cleaner, it works like new. Before I had to literally smash the button down to get the 40D to take a picture, pushed 1/2 way down it worked fine, just didn't take pictures before it was cleaned. The electrical cleaner has a tube contacted to the spray head so was easy to direct spray into crack of shutter button. The rotary switch on top, behind the shutter release, also slipped, the spray also resolved this issue.


I can now say it is safe because I did it and my camera is now working perfectly.

I found a thread on Canon Rumors by a photographer having a similar problem. After some hesitations, he decide to clean as explained in the question, using isopropyl alcohol, and the problem was solved. I also found a video on youtube explaining the procedure in details, and below there are tenth of comments saying that it works. So I decided to do it, and it worked also for me perfectly.

Note that I had to do it three times. Moreover, you can see dust being washed away as the alcohol flows from the inside to the outside, around the shutter button.

More information on the complete procedure here : http://www.youtube.com/watch?v=tB_gSqyidI0

Make sure you use pure isopropyl and to follow the instructions in the video carefully (there is some risk that the upper LCD screen might get damaged if improperly done, it seems). This is of course at your own risk, but for me it worked like a charm. I paid only 1 EUR for 15ml of pure isopropyl!

  • \$\begingroup\$ I haven't watched the video or anything but take both batteries out of your camera if you're going to do this. my.safaribooksonline.com/book/photography/30000lti00235/… In theory, as long as there is no current flowing, you should be safe to do this. I've done it with other electronics, you just need to make sure there is no current and give it plenty of time to fully dry. \$\endgroup\$ Jul 16, 2013 at 14:25
  • \$\begingroup\$ I am not recommending you do this, just trying to give some tips to help make it safer. \$\endgroup\$ Jul 16, 2013 at 14:27
  • \$\begingroup\$ As I said, I already did it so it is a bit too late for advises. Hopefully it worked anyway. Notice that pure isopropyl alcohol is not conducting electricity. \$\endgroup\$
    – arovai
    Jul 17, 2013 at 8:18

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