5d mkii CF Card Format Error

Give this formate a try SD Memory Card Formatter it often fixes things. Its also possible the SD card is damaged or just worn out.

c f card not format format with camera canon camera mark ii

I had a Canon camera that used a CF card, one of the pins got bent, and it gave me a similar problem. I used a wire wrap tool (Basically a very thin tube that fitted over the pin) to pull the pins straight.

Suggest you look closely at the pins they should all be at the same pitch and not bent. Also it is possible when putting the CF card in, to push a pin inwards, so check that all the pins are the same length and that there are none broken off. If there is any discrepancy, I suggest returning it to who ever repaired it.

I also suggest that you only remove the CF card when absolutely necessary. You can connect the camera to the computer to download files rather than take the CF out.