I have a S5 with a 64gb samsung evo microsdxc card. The card was working fine and was filled with music and photos and one day the phone just stopped recognizing it. All the apps that were on the card would no longer run. I pulled the card out and put it in a card reader and got all of the data off. Then I reformatted it as exfat with windows7 and the S5 still will not mount it.
When I put the card in and go to Settings -> Storage -> mount SD card. I get an error message "SD card is blank or has unsupported file system" . If I go ahead and tell the S5 to format the card it says "card is safe to remove" then nothing happens. Attempts to mount the card again repeat the same messages. I have tried two different microsd cards both cause the same behavior. Both cards are fully readable in a card reader connected to a computer. I've even done a full 64gb read-write test on the card and its working.
I tried to clear the app cache and I tried a full factory reset and re-installed all my apps and still it wont recognize either card.
I've had the phone for less than a year and I am wondering if its still under warranty. I really need the extra storage for music / photos / apps the phone only has 16gb built in.
