70D no longer recognizes cards.

[GovtLawyer]

I was about to go out with my camera and was checking the card and battery to see if I wanted to change either.  Looking in the camera I saw that the card was half filled and needed changing.  The battery was in the same state.  I do not remember in what order I did this, but I changed both the card and the battery.  I never open up the card door or take out a card while the camera is on.  Now, my camera says there is no card in the camera.  I put back the old card and iot says the same thing.  It simply does not recognize any card.  

It does not recognize any card.  I put both cards directly into my Mac and all of the images are still there.  So, it does not seem to be a problem with the card.  It seems as if the camera just stopped recognizing any card.  I have exchanged each card and battery in the camera and get the same results.

Any suggestions?

[GovtLawyer]

As the original poster, a follow up is in order.  I don't know what was wrong with my 70D, but after that episode with turning write protectoion on and off, the problem never came back.  I took the 70D and a new 80D on an African safari in September and it performed flawlessly.  I wish I could be of more assitance.

[Blade]

You know, I tried that but maybe I missed a step or something? Can you take me through it again maybe step by step? Only when you can. Thanks GOVt-thanks for your help. 

[GovtLawyer]

I'm sorry, I can't help you.  What I did was more than a year ago and I do not remember exactly.  Look at my post again.