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]