! Card Error Message. My Fuji 4900 suddenly started displaying the !Card Error message. I tried

Question

My Fuji 4900 suddenly started displaying the !Card Error message. I tried the two Smart Media cards I own, after gently cleaning the metallic surface and both gave the same message. I then replaced the NP-80 battery thinking that might be the problem. The camera still displays the card error message and is unusable. I bought a new Smart Media card as the others had been used a lot and I thought that might be the problem. Even with a new memory card and new battery the camera still displays this message and won't work. It has been a fantastic camera and has given me great service. Can anyone find a solution to this problem? I need it desperately and can't afford a new one right now.