I've got a 2 year old 30D with about 5000 clicks on it that's developed a problem, probably with the mirror. It first happened a couple of months ago, then again yesterday. Sometimes, for a time the camera will take a totally black frame for alternate shots. It sounds like the shutter fires, but the mirror definitely doesn't. It is always one good shot, then one bad shot alternately. Then after a while, it will start behaving itself again and some time later it might start acting up again.
Based on this rather fluffy description, does anyone have an idea what the problem might be? I don't have a Canon service center nearby and the closest one (50 miles away) seems to have mixed reports so I was hoping to be able to get some idea of what's wrong and what it might cost to get fixed before I think about sending it away (I'm in the UK). If it needs the whole mirror box replaced, I could see me hopping to a 40D or 50D instead!
Thanks in advance for any light you may be able to shed on this...
