I'm seriously bent outta shape right now. My 5D is not reading the Compact Flash. I've tried updating the Canon software, reformatting the card. I bought a brand new CF and the camera still does not read the card. It too gave me an error message 'cannot access card.' Has anyone else had the problem? One would not expect this from an expensive high end Canon camera.

Hi Charles,

I had an identical problem with a Canon 5D Mk11. It turned out to be one of the pins bent in the CF card slot, possibly caused by accidentally trying to put the card in upside down. It should be possible to see with a magnifying glass and a torch. I gave up trying to straighten mine with various tools and had to take it to be completely disassembled by a specialist to have the connector on the board replaced.

Roger

The best thing to do is to send it to service, in this way you will be sure they will find out a way to fix your problem.