Hi guys I have the same problems, had an s3 with a 16gb microsd card then moved this card to my new note2 a week later got a message on the phone telling me unable to read sd card . Put the card in my pc and only show 30mb available, Did some research and found out that my sd card file system has some how been changed by the phone from fat32 to raw. My pc and phone cannot read raw sd cards so now trying to find a way to format the card back to fat32. Tried on windows but won’t work, tried in dos but does support raw . So any help guys?