Nooo!! 5DII "Error 20" and nasty-sounding shutter noises

[Feanor]

I'm getting "Error 20 - shooting is not possible. Turn the power switch to <OFF> then <ON> again or re-install the battery."


At the same time I'm getting a nasty-sounding shutter noise - as though the camera is trying to trigger the shutter but can't quite manage it.


I've searched on the net and mostly it seems to be an RTM issue. The suggestions that Canon make to sort it out don't strike me as relevant when I'm also getting this nasty clicking noise.


To be honest, and obviously I'm only saying this anonymously online, I'd just cleaned my camera out - not the sensor, just the housing and focusing screen as I could see specs of dust in the viewfinder. I know compressed air is meant to be a no-no but apparently Canon engineers and as a professional tech myself I understood the risk to be freezing liquid squirting out and damaging the sensor. So I bought the best quality "invertible" air I could find and used it in very short bursts - I'm pretty good with this sort of precision work as it's a part of my job so I thought I'd be OK. It went well but the pressure from the air lifted the mirror a couple of times. I must have taken 30-50 or so images afterwards while testing and trying to improve the micro-adjustment, but could the air lifting the mirror have damaged the mechanism?


I've also just fitted my new battery grip but am only using one battery as the other is on charge.


The body's still in warranty luckily and anyway I was planning on taking it to the local repair centre soon to get my lenses calibrated.





In the meantime though - help!! [:'(]





EDIT: I just gently lifted the mirror very slightly with a soft piece of plastic and it seems to be working now... I just took a good hundred or so frames in continuuous shooting and it didn't miss a beat! [:S]

[wickerprints]

I really hate to say it, but let this be a lesson to you. Don't go poking around inside the mirror box unless you know what you're doing. Don't believe everything you read online.


When people talk about using compressed air, they're most likely using it to blow on the sensor, which means the mirror is flipped up and the shutter curtains are retracted. These very delicate components are therefore out of the way and less likely to be damaged by the strong forces generated by compressed air. By blowing directly on the mirror, you likely caused the mirror to misalign.


It's not the freezing or static buildup that is the problem with compressed air. It's the fact that you are blowing with a LOT of force. Haven't you ever taken the air and blown it against your fingertip? It shoots out with enough force to put a dent in your skin. Now imagine putting that kind of force on a shutter or focusing screen or mirror assembly. Not a good idea.


The mirror is one of the most sensitive moving parts in your entire camera. In some respects it is even more sensitive than the shutter. Don't attempt to clean it yourself. Don't blow on it, don't even TOUCH it. If it's dirty, it won't affect your images, nor will it cause any other malfunction. But if you knock it, you can cause a lot of problems.


If your camera is still under warranty, I would have it sent in to Canon for inspection. Don't say anything about what you did, just tell them you had an intermittent error and wanted to have it checked, even if it seems to be working fine now.





Takeaway: just leave the compressed air alone.

[Feanor]

I know how powerful compressed air is, and you're right. But I hate it when people just say "don't do this" and don't give any reasons, which is all that I ever read on the Internet about compressed air. Fact is that if you know its limits and know what you're doing it is very useful for cleaning all sorts of sensitive equipment.


To be honest though, it's fairly easy to regulate the power of compressed air (I was very gentle with the focusing screen to prevent it being blasted out of the screen holding tool) so I still think it's a viable alternative if used at low power. I've now taken about 300 shots with the camera since this happened and it's still quite happy, so I'll keep testing it rigorously over the next few days - there's no point sending it in if the fault doesn't happen again as they'll just think I'm wasting their time. And no, I wasn't planning on telling them what I'd done! [] lol

[wickerprints]

My rationale for sending it in is that you may have also caused misalignment of the secondary AF mirror, or some other problem that you have not detected either because it is subtle, or it has yet to manifest itself. Should a more serious failure occur out of the warranty period because of this event, then it will cost you more. That's my concern.

[Feanor]

I see . Well I intend on taking it to a repair centre here in Paris soon ayway to get my lenses calibrated as I said so I'll mention the error to them as well and ask them to check the mechanism (it wouldn't take a rocket scientist to realise it was the mirror even if I hadn't been fiddling with the canned air).

[Bombsight]

Peace of mind is worth a lot!


It may be working fine right now .... but it could fail right when you need/trust it most ... like on vacation.


Hows that for good reason to leave compressed air alone?[:'(]


Get a Giotto rocket blower!

[peety3]

I know how powerful compressed air is, and you're right. But I hate it when people just say "don't do this" and don't give any reasons, which is all that I ever read on the Internet about compressed air. Fact is that if you know its limits and know what you're doing it is very useful for cleaning all sorts of sensitive equipment.

There's a liability if someone says "the limits are X" and it turns out the limits were a bit different (or a lot different). If Canon says "don't do it", they can clearly charge you for any and all repairs if you "do it".


Fact is that compressed air is very good for sandblasting. Obviously some sand or grit is needed to complete the process, but unless you have certified, guaranteed, clean air, you're accepting a lot of responsibility and risk attempting what you've done.