I have used 2 (Two) 32GB Sandisk Memory cards with my Samsung Galaxy S3 in the space of 5 months, both dying out on me suddenly, taking away with them valuable data. The last happened just last week.
I was very worried and even considered the possibility that the cards were fakes. However, common sense told me the cards were most likely the real deal because they were bought from BestBuy. Idid a quick search on the internet, on the off chance that some whiz kid with some oracle may have found a solution i could benefit from. What i found was very revealing.
They were tales of woes of how Samsung flagship phones and tablets, including the Samsung Galaxy S3 (perhaps the S4 too?) and Galaxy note, have ruined their microSD cards. If you were lucky, you would get some warning signs – your card acting up for a while, starting and stopping intermittently before failing permanently. It will stop being recognized by any computer or phone.
However, most do not get this warning.
Rumour even has it that the issue is not limited to Sandisk MicroSD brands alone. Apparently, something in the phone is destroying these cards. CNET even published an article on this issue in March 2013.
Unfortunately, no solution has been proffered by Sandisk or any other microSD manufacturer. For now, we can only hope and wait.