After someone telling me that there is a known problem with some Sandisk micro SD cards and Samsung phones, I searched and found this. Same symptoms, phone started freezing up, requiring battery to be removed, fast battery drain, and eventually the SD card couldn’t be read any longer! Now if you try mount, it says its blank and suggests a format.
Putting the card into WinXP machine, Win7 laptop, Raspberry Pi with 3 various micro SD card readers which are working with other cards just fine … nothing, can’t see the card as a drive. Have tried all sorts to try recover the data, nothings working.
It’s a SanDisk 32Gb Class 4 … less than 1 years old 
Not about to send the card off for a replacement as there is still data on there … I just can’t see or get to it due to cards HW failure.
