Solution 2: Make sure that the microSD card you’re using is supported by the S4. Solution 3: If the card was used in a previous device, it is possible that the card may be write protected.

To format a Kingston microSD or microSDHC card, you have to first disable this write protection.

Here are some ways to fix your SD card if it is damaged or corrupted. Sometimes, your microSD card is not working, regardless if you have already cleaned it up or plugged it into another device.

A write-protected card cannot be formatted. To remove the write protection, you will need to install the card in the original device and remove the write protection.