If your camera is displaying "SD Card Lock", "No Memory" or "No Card" then follow these steps to remedy the problem.
1. Make sure that the card is not physically locked. Many SD cards have a small toggle switch or lock on the side. With the camera OFF and SD card removed, look on the side of the card to see if it is in the locked position. If it does not indicate which position is locked, move the switch to the opposite position. Put the card back in the camera. Turn the camera back ON. If it no longer reads the error message, then the card was physically locked. If it still reads the error message, it is most likely due to a problem with the SD card itself.
2. Make sure you are using a compatible SD card.
3. Make sure the card is formatted correctly.
4. Make sure it is not time to replace your SD card.
5. Make sure the SD card slot of the camera is free of debris. This should be done with a can of compressed air, such as “Keyboard cleaner”. This can be purchased anywhere office supplies are sold.
6. If none of the above resolves the issue, then replace SD card with a new compatible SD card.