I have a microSD card that has become read-only. I cannot write to it, or delete files from it, or format it, or repartition it. (Various computers think they can delete files, but after removing and reinserting the card, they are back).
SanDisk have offered to RMA the device under warranty, but I am concerned about sending it back with my data still on it. Is there any way I can wipe the card at a physical level without damaging it (voiding the warranty).
I guess a strong magnet is out of the question as flash isn't magnetic storage.
Edit: Clarified that this is a microSD card. It has no write-protect switch. I have also tried using
dd - no result; the command hangs awaiting I/O. I have also tried using a different card reader and a different host computer (one Windows 7, the other Ubuntu) - and also without a card reader by trying to format the card while in my Android phone. The card is definitely broken.
Update: I explained the situation to SanDisk and they offered to let me return the card broken into pieces. Turns out microSD cards have about the same breaking strength as a hard matchstick.