Repair Corrupted and Undetectable USB Flash Drive

How to repair unreadable USB Flash Drive when Windows cannot recognize the USB Drive (Please insert a disk into Removable Disk).

For a variety of reasons, a USB Flash Drive can get damaged and become undetectable by Windows or any other OS.
If a USB memory stick is no more accessible by the actual operating system, the user has no chance to run any “recovery tool” and not even the regular bad sector repair tool by Windows (CHKDSK). In this case, the user gets error “Please insert a disk into Removable Disk” and the USB drive icon appears empty or unmounted.

When a USB pen drive gets into this state, you need to repair its controller on a firmware level.

How to repair USB Drive controller firmware?

First of all, you need to know what model and serial number of the Controller is built into your USB Drive.

Note: If your USB flash drive’s manufacturer is, for example, Transcend or SanDisk this does not necessarily mean that the controller is from Transcend / SanDisk as well. It can be any other random manufacturer; such as Toshiba, Silicon Motion, Samsung, Intel etc.

Before we start: Get sure that your USB data storage device is not physically damaged. This article threats only logical damages. In case your USB flash drive is broken in a physical way – cracked, crashed, sqeezed, damaged by water or fire etc. you need to repair it by using a soldering iron rather than by using software.

Possible USB Drive damages not threated in this article.

1) Repair physically damaged USB Flash Drive:

2) Repair unformattable USB flash-disk:
Accessible but not readable. For example, “Windows couldn’t complete format”. To fix this, you may format your USB Flash Drive on firmware level by performing a “Low-Level-Format” (LLF).

3) Recover files deleted from a USB thumb drive:



Let’s start fixing your inaccessible USB memory thumb drive.

Step 1: Determine USB Drive Controller.

To find out the model of USB Drive’s controller we need some kind of “firmware reader”. In this case it will be “ChipGenius”. You can use Google to find this software (Freeware) or you can follow this link to download it: (Scroll down for the latest version).

Step 2: Start ChipGenius. Now we can see the “Controller Part-Number”. Hit right mouse on ChipGenius output window and paste the copied information to an empty text file.

determine usb flash drive controller

Step 3: Search for your controller firmware on the internet. In this example, the corrupted Verbatim USB Flash Drive needs firmware “SM3257ENAA”. Put the Controller Part-Number of your USB drive into Google search or use any firmware vendor of your choice.

Note: Please beware of garbage! Many bogus websites claiming to have the latest version of firmware (which does not even exist). Such websites spreading malware and trash. A trusted source for USB drive firmware is:
Use a virus scanner for every .exe file that you download or use an online virus scanner:

Step 4: Download and start a firmware updater for your USB Drive and hit the button “Scan”.

scan usb flash drive chip

Step 5: Hit the button “Debug” and give password “320”.

debug usb flash drive controller

Step 6: Hit the button “Start” and wait until the reinitialization is completed. It can take a few minutes, depending on the capacity of the Flash Drive.

Step 7: After the operation is done, you will see a green “OK” and the capacity of the USB Disk.

repair usb flash drive controller

Step 8: That’s it! Now you need to go to “This PC” or “My Computer” and open “Removable Disk” or “USB DISK”.
After repairing the unreadable USB flash drive, you may use the regular drive tools, such as chkdsk (Automatically fix file system errors), Format or Low-level-format.

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