08-08-2014 07:11 AM
Dear member of SanDisk Community, welcome.
1- Please, first of all, clean the pins on the card and the phone slot, with isopropyl alcohol (or common).
2- Try another SD card in the phone.
3- Put the SD, in a laptop, directly to its port, with a good adapter (not a card reader).
3- In Star / My Computer, on the card icon, click the right mouse button, and then click in Properties / Tools / Error Checking and Repair.
4- If still bad, try formatting with (free): USB Flash SD Formatter 4.00, http://filecloud.io/jqtu1byc
5- If there is no joy, please, do not grieve more, friend, return it, is defective. See link: http://www.sandisk.com/about-sandisk/contact-us/
Luck, and then you tell us, what happened, please.
Regards, Alfred. (Google translated)