SD Card won't mount

[AC Question]

I have a Samsung galaxy s4 and my phone won't mount my SD card or even acknowledges that I have an SD card in my phone has been happening ever since I got the phone brand new.

 

[B. Diddy]

Welcome to Android Central! The card might be defective or counterfeit. Is the card brand new as well? Insert the card into your computer--if the computer doesn't recognize it, then it's dead or defective.