I am using a Sandisk 8 GB micro SDHC card on my MileStone. The card is detected and mounted. I can read data from the SD card, but cannot write to it. There is no error when I attempt to write to the card.

It appears as if it's working fine, but after unmount and re-mount, the data written is gone. Even if I format it, it will restore to the previous state.

At last, I tried to format it, but the operation system formatting utilities were not working, it says

Windows was unable to complete the format

Then I use the "SD Formatter 3.0 Beta" from "http://www.sdcard.org/consumers/formatter_3/", and it says

The nemory card is write-protected. Please release the write protect switch."

but I can't find any switch on my micro SDHC card or SD card reader.

I see some useful information on that web site. It says

The SD/SDHC/SDXC cards have a "protected area" on the card for the SD security function. The SD formatter does not format the "protected area". Please use the appropriate application software or SD host device which provides SD security function to format the "protected area" in the card."

I think my card may be wholly protected. How can I format it?


2 Answers 2


Are you using a Micro SDHC adapter. Basically are you putting the Micro SDHC into a SDHC card, which in turn goes into the card reader.

I ask this because the adapter can have a write protect switch on it, even if the Micro SDHC doesn't. Example of write protect - http://www.transcendusa.com/Products/ShowImg.asp?ModNo=195&vplay=yes

If not your card has gone faulty. Save your data and return it to scandisk for a new one - http://webcache.googleusercontent.com/search?q=cache:ft-qKl6oGFAJ:communities.sandisk.com/sandisk/board/message%3Fboard.id%3Dmobile%26message.id%3D1005+micro+SDHC+write+protected&cd=1&hl=en&ct=clnk&gl=uk


Yes, a full size SD Card/adapter has a write protecting switch. This tells the computer or device that you want to prevent writing to the card. Micro SD Cards do not have this switch. If other cards work, and toggling the switch on the adapter doesn't improve the situation, we've isolated the fault to this specific card.

I've been told in the past that cards can enter a write only mode if they have detected a pending failure. Preventing writes will help the card last longer to give you a chance to recover any data. I guess it's like S.M.A.R.T. on a hard drive.

I'd love to cite an official source, but I'm coming up short. I'm sure it was something I saw on a random blog years ago.

My suggestion is to contact the manufacturer and seek a repair/replacement as the card is faulty.

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