Yrurtj

I have 8GB flash memory stick. Sometimes ago I formatted it to be able to install Windows from it. I can't remember what exactly I did but I think I wanted to be able to install Win 7 64-bit to boot in EFI mode.

Now I can't reformat it nor in Windows nor in Linux.

I tried to convert it to MBR from GPT with gdisk by gdisk /dev/sdc, then w (to write GPT from memory to the drive as the tool reported "Found invalid GPT and valid MBR; converting MBR to GPT format in memory"). Then gdisk /dev/sdc again:

    # gdisk /dev/sdc

GPT fdisk (gdisk) version 0.8.8



Partition table scan:

  MBR: MBR only

  BSD: not present

  APM: not present

  GPT: not present





***************************************************************

Found invalid GPT and valid MBR; converting MBR to GPT format

in memory. THIS OPERATION IS POTENTIALLY DESTRUCTIVE! Exit by

typing 'q' if you don't want to convert your MBR partitions

to GPT format!

***************************************************************

, opened expert tools with x, z (to destroy GPT).
Here is the output:

Expert command (? for help): z

About to wipe out GPT on /dev/sdc. Proceed? (Y/N): Y

GPT data structures destroyed! You may now partition the disk using fdisk or

other utilities.

Blank out MBR? (Y/N): Y

#

then tried to delete a partition with fdisk

# fdisk /dev/sdc



Command (m for help): p



Disk /dev/sdc: 8086 MB, 8086618112 bytes

249 heads, 62 sectors/track, 1023 cylinders, total 15794176 sectors

Units = sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk identifier: 0x000a07ca



   Device Boot      Start         End      Blocks   Id  System

/dev/sdc1   *          62    15793073     7896506    7  HPFS/NTFS/exFAT



Command (m for help): d

Selected partition 1



Command (m for help): p



Disk /dev/sdc: 8086 MB, 8086618112 bytes

249 heads, 62 sectors/track, 1023 cylinders, total 15794176 sectors

Units = sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk identifier: 0x000a07ca



   Device Boot      Start         End      Blocks   Id  System



Command (m for help): w

The partition table has been altered!



Calling ioctl() to re-read partition table.



Error closing file

After this I tried to pull out and plug in the stick again but NTFS mount error window appeared each time.

I also tried to rewrite an initial drive area with a test content with badblocks

sudo badblocks -w -s -o /tmp/usbstick.log /dev/sdc

and with dd

sudo dd if=/dev/zero of=/dev/sdc bs=1024k count=2

but I couldn't reformat it to usable state.

Is there a way I can restore its factory state?

My system: Linux Mint 17.3

UPDATE

# blkid

/dev/sdc1: UUID="675599A00CE338FC" TYPE="ntfs"



# usb-devices

T:  Bus=01 Lev=01 Prnt=01 Port=03 Cnt=02 Dev#=  4 Spd=480 MxCh= 0

D:  Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1

P:  Vendor=1307 ProdID=0190 Rev=01.00

S:  Manufacturer=USBest Technology

S:  Product=USB Mass Storage Device

S:  SerialNumber=00000000000004

C:  #Ifs= 1 Cfg#= 1 Atr=80 MxPwr=98mA

I:  If#= 0 Alt= 0 #EPs= 3 Cls=08(stor.) Sub=06 Prot=50 Driver=usb-storage

I hope, I understand properly what you want.

Recently, I had a similar issue. It was after making a bootable USB drive for installing ubuntu. Therefore, I used the dd command: sudo dd if=*.iso of=/dev/sdb . Afterwards I could not access the full storage capacity of my drive (that means: also after formatting my device, further, programs like fdisk did not show its capacity).

Further, applying gparted, I could only reduce the visible amount of usable disk-space, but not restore ist to the maximum of appr 8 GB. Also, gparted wouldn't show me the 8 GB but 4, 3, 2..., whatever I reduced it to. At least using Windows, I could not solve the problem (but I didn't try extensively nor did I have admin privileges). What I did then was to delete all partitions on my usb-stick with fdisk and rebooted the computer. Then the storage capacity shown was around 8 GB again, as I expected.

Your usage of dd command sudo dd if=/dev/zero of=/dev/sdc bs=1024k count=2 won't write zeros onto the whole drive.

You said, you cannot format your usb drive. Further you said you deleted all of your partitions. So my suggestion is, that you run the following command to format your drive (Maybe you will have to do this using the sudo command):

mkfs.vfat -I -F 32 /dev/sdX

where X has to be replaced for the letter of your drive. You can try to write a new partition/partition-table onto your drive before, using sudo fdisk /dev/sdX (d to delete partitions, n to make a new partition [e.g. over the whole device] and with t you could change the type of the partition table; with p you can check the partitioning of your device). But anyway, you wrote, you already used fdisk.

I searched on google, I didn't find information, that linux mint is using a different command for formatting than at least most other linux distributions.