All too many moon ago, back in the days of a Canon G2!, a 128MB CF card failed on me in camera, and it failed many rescue attempts...it got relegated to duty for computers but not Canon digital cameras. It eventually got thrown in an idle memory stick bag that I keep in my desk
I just pulled it out (over 10 years after it went into that bag) and reconfirmed: even today it still would not function in a Canon digital camera but it would still function in a PC.
- I have just low level formatted it in my PC, stuck it into a Canon dSLR and the dSLR said it needed to be formatted in camera, but then it also said the CF could not be formatted by the camera.
A primary investigation proving that a CF can be bricked for photographic purposes in camera, but still function useably for general digital data storage -- including transfers/viewing of JPG files but not in a camera!