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Sudden Card Error


I received a sudden card error on my 7D.  I can't read the card on my card reader either.  I thought it was an issue with the card so I purchased another card.  The camera continues to show card error on a brand new card.  I'm afraid to try any of my old cards as I may lose the data.  Any ideas?



Save the data to your computer and then you don't have to be afraid of losing it.

Are these full size cards, or micro cards with an adapter?

Do you format the cards in camera?

"Are these full size cards, or micro cards with an adapter?"


I don't believe there is a micro CF card perhaps there is and I just am unaware of it.


"Do you format the cards in camera?"


I hear this advice all the time to only use your camera to format the memory card. But in my experience a CF card formatted on a Windows machine works as well. I have never seen a problem. Perhaps I have just not done it enough as I usually do use the camera.  I do not know if this is true for the Mac folks. Macs are so screwy I wouldn't even try it.

EOS 1DX and 1D Mk IV and several lenses!

The Compact Flash card which had been in use, suddenly became unreadable in the camer and even in my card reader, so I can't retrieve the photos already on it.  I bought another SanDisk Extreme Pro 32GB Compact Flash card and when I put the new one in my camera, I received a card error again. 


As KV suggests, make sure to transfer data from one of your working older cards to your computer then try to format it inside the camera.


I believe the 7D uses CF cards.  The pin connector on those is subject to damage from bent pins so if the old card now doesn't work use a good light and magnifying glass to check for bent pins.  If there is, then it needs to go in for service UNLESS you are skilled at doing fine work.


Potential bending of CF pins is one of the good reasons to be very careful where you buy cards because counterfeiting is very common and a lot of the knockoff cards are poorly manufactured.  A colleague damaged a camera with a fake CF card she bought online from a major online retailer, the pin holes were improperly sized in this very poorly made counterfeit card.  The major camera retailers like B&H are safe for card purchase as are the physical locations of major retail chains.



EOS 1DX M3, 1DX M2, 1DX, 5DS R, M6 Mark II, 1D M2, EOS 650 (film), many lenses, XF400 video


First I agree with Rodger so do as he suggested.

Secondly, " I'm afraid to try any of my old cards as I may lose the data.  Any ideas?" Smiley Surprised


What do you mean?  You are storing photos on the CF cards instead of copying them to your computer?  This is an unwise practice. The best practice is to upload to your computer as soon as you get home.  You don't even have to remove the CF card.  Once the photos are fully moved to the computer and a backup copy made, format the CF card.


And, make sure you are using the correct CF card recommended in the manual. Type I and Type II Compact Flash cards or the faster UDMA standard or the Compact Flash+ standard. Personally I prefer smaller CF cards in the 16 MB range.

I have owned two 7D cameras and they served me well.  I love the 7D model, great camera.


EOS 1DX and 1D Mk IV and several lenses!

Thanks!  I've lost all my photos on my computer in the past, so as a precaution I offload to my computer and retain the images on the card.  I know, not great.  But I was heartbroken when I lost all my other images. I have an external drive too that I back my computer too, and even on this some of the old  images are getting wonky and not opening. 

"...I was heartbroken when I lost all my other images."


I was in the photography business for over 40 years, still am but at a much reduced rate as I have retired, but losing a photo was unacceptable. You need to fix that storage problem before going on.  External HDs are very cheap these days. Relying on a CF card as a storage medium is not satisfactory.

Secondly you need to have the 7D checked out. Call Canon and set up a C&C for it. Tell them the issue. IMHO, 32MB CF card is too big. I much prefer smaller ones even 8MB but 16MB is a good compromise.


I hope this will end you losing any more pictures. I know pictures mean a lot and certain ones mean a whole lot.

EOS 1DX and 1D Mk IV and several lenses!

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