If you can put the SD card in another device, such as a PC or card reader and it is shown, the card is okay and the trouble is the card reader in your camera. If it is in your camera, I would try resetting the options to factory default on the slim chance that might fix the problem. Otherwise your camera card reader is probably defective.
Answers & Comments
If you can put the SD card in another device, such as a PC or card reader and it is shown, the card is okay and the trouble is the card reader in your camera. If it is in your camera, I would try resetting the options to factory default on the slim chance that might fix the problem. Otherwise your camera card reader is probably defective.