My Sandisk Ultra has gone crazy

I have a Sandisk Ultra Micro SDXC 64GB card which I use in my Samsung s4 phone for adding lots of music.  All has been working fine for 18 months or so.  I load / remove music onto it using Windows Explorer.

Then as of this week I couldn’t copy new music onto it, nor could I delete old stuff.  Or actually it seemed I could (it looked like all had been done fine, but then a few hours later it restored itself to its original state: with the old music still on, and not the new music).  I went through this quite a number of times coz I thought I was going crazy.  Anyway I finally realized I was not when playing a new song actually played one I had supposedly deleted.  So I realized the drive had got its directory file allocation tables screwed and probably needed to be reformatted.

So I tried this using Windows.  However Quick Format failed, so I tried the full version.  Well after waiting 30 mins or so (grr) it finally said it cannot complete the formatting process (“windows was unable to compete the format”).  So I downloaded SDFormatter to see if this would help.  But trying to format with that, I just got the error: “The Memory Card is write-protected. Please release the write protect switch”.  But it is not, I set the write-protect on the card adaptor 10x to forward position.  So then I tried another card adaptor, but no luck here.  (I also tried this with another micro SD card on the same adaptor, but did not get this error)

I thought then to try chkdsk /f h: from the command line, but I got the really useful statement:

"The volume has been successfully checked, but Windows was unable to mark the volume as clean.

Windows has checked the file system and found no problems."

No viruses found either.  Has this card just died?  Or can I use some other method to reformat it?


in that case the card seems to be write protected and that is a hardware defect and there is nothing more you can do with the card. you can go to the place of purchase to replace the card or contact sandisk support direct to claim a warranty replacement.