Unable to format partitioned 32 GB micro SD card

Question

I am unable to format my 32 GB micro SDHC card after I made two partitions on it. First partition is FAT32. Second is 4 GB ext3.

Now I am unable to format my card and delete partitions on it. It seems to get locked. Data and partitions remain intact, even after formatting.

P.S. I tried tools like EASUS, minitool, HP format utility, but nothing helps. And I am using the SD card adapter on my ASUS laptop.

Edit: It's a micro SD card. Pics attached!

                               

Answer 1

If you can boot a Linux OS which has physical access to the SD device, you might try the following.

First, be sure to identify the device. Often, you might plug your key, then run dmesg. It usually tells you something. Let's pretend it is about /dev/sdi (but be careful, a mistake could wipe all your data!; don't use /dev/sda or /dev/sdb these are probably real hard disks).

So run first

fdisk -l /dev/sdi

to be convinced from the output that it is indeed your SD thing.

Then, wipe the entire partition (and lose all the SD data!) with

dd if=/dev/zero of=/dev/sdi bs=4k count=32768

then use fdisk or gparted to remake the disk partitionning, and finally run mkfs.ext4 /dev/sdi3 to e.g. make an EXT4 file system on the 3rd partition of your SD thing.

Be very careful (notably, replace /dev/sdi by the relevant /dev/sdx thing where x is the appropriate letter).

Answer 2

2 things can be going on here:

• The information in the first sector (the MBR) is corrupted which confuses the hell out of the Operating System. This prevents normal tools to properly wipe it.
  It should be possible to bring it back in usable shape but you won't be able to do that in Windows. Windows doesn't know how to handle multi-partition USB-removable devices (which is what the card-reader presents itself as to Windows) in thw first place and refuses to work in a normal way if it sees a partition table with more than 1 partition.
  I recommend you try the GPartED live-CD (or USB-stick). You should be able to write a fresh MBR or GPT partition table to the card. If that doesn't work see the next point below.
• The card is damaged and doesn't actually write anything properly anymore. In that case throw it away and get another.

Answer 3

To erase the MBR in Windows you need a Low Level Format tool like this from HDD-Guru. Now start the programm with administrator rights.

Click on:

• Continue for free
• Choose your sdhc card (be sure to choose the right one)
• Click Continue
• On the tab "LOW-LEVEL-FORMAT" choose "Perform quick wipe"
• Click on "FORMAT THIS DEVICE"

Now all Partitions on the sdhc should be removed. And you can format it in Windows.

Answer 4

1: If your card is "locked" like you mention, you need to physically unlock it using the physical switch on the side of the card.

2: Doing a "Low-Level" format like suggested will do the trick but it's way more work than needed. You can easily re-partition the card or reset the MBR using a portable/small program like BootIce

Here's how to do it:
~ Select the SD Card from the "Destination Disk", drop down menu.
~ Click "Parts Manage"


~ Select "Format this part" if it has 1 partition.

OR
~ Select "Re-Partitioning" if the drive has more than 1 partition and then decrease/delete all extra partition until only one is remaining. This option also allows for changing the partition tables (ie: starting at first sector, multiple entries, etc...)

~ You can also access or change the MBR/PBR information (BOOTMGR/GRUB4DOS/NTLDR boot) by clicking "Process MBR/PBR" instead of "Parts Manage" in the first step.