Not long ago, my 5DMK II just stopped working. Canon's assessment... replace all PCB's because they don't know what's wrong with it. Cost to me, $1600 for a new camera body. A week before a wedding too!
Today, I flew home from four days in Tasmania, had a blast! Trekked all over Liffey falls, through rain-forrests, into Cradle mountain area's, WOW, what an awesome time and SPECTACULAR landscape photography captured!
I just pulled my CF card out of the camera, plugged it into the card-reader on the PC as usual....
error message -file corrupted - all data lost.
Plugged it back into the camera - error message - this card is not formatted for the camera, would you like to format?
Guess what? I have another wedding to shoot on Saturday....
I hate technology.