How to Understand Flash Drive Not Detected Problems

If you have a flash drive not showing up on your computer when it’s plugged in, you may have a serious problem. There are a couple different scenarios that can be causing the drive to not be detected.

Flash drives have a few different places, or components, that can fail, or become corrupted, causing the drive not to be recognized.

Failed components can cause flash drive not recognized errors

The most common flash drives are made with a printed circuit board where all of its components are attached. This includes the memory storage chips (or NANDs), a controller chip, as well as some resistors, capacitors, and other electronic components that communicate together with the computer.


Other flash drives have all the components integrated withing the chip itself, meaning they have no PCB board. These are called monolithic flash drives, and are the most difficult to recover.


If any of these components fail, the computer may give you a USB device not recognized error. This is especially true when there is damage to the controller chip and NAND(s).controller chip on flash drive

Flash recovery by reverse engineering and virtualization of the controller chip

The controller chip is responsible for error correction, encryption, and translating the data from the NAND to the computer. This can become corrupt for multiple reasons.

If the controller chip becomes corrupted or suffers from physical damage (for example chipped or cracked), then the drive will produce this kind of error.


NAND chips also by nature encounter bad sectors similar to that of hard drives. Flash drives have built in processes to compensate for these as well.

How to avoid flash drive controller chip failure

One of the most common reasons a flash drive will not show up on the computer, is due to the controller chip failing. Usually this is because the drive has been removed form the machine improperly too many times. This can also happen with a hard drive not being recognized by Apple, iMac, Macbook products.

Realistically it only takes one time in some instances.

Flash drives should always be ejected from within the operating system before it is removed. This is so the power is turned off to the USB port temporarily while the device is unplugged.

Most people do not perform this step, and therefore end up with a damaged flash drive. It’s basically like taking the cord of a power plug and ripping it out of the power outlet.

Unplugging the flash drive without ejecting it first can cause a surge of power to cross over the usb components and basically fry them. This will likely end up with a short on the board which can damage the chips, even the memory chip (NAND).

Device not recognized because it is physically broken.

Another way is if the stem legs are detached or broken. Normally this results in the computer not recognizing the drive enough to know that something is plugged into the USB port. It really depends on how bad the legs from the stem were broken off.

There are paper thin pads that connect most usb connectors to the PCB board on a flash drive. Some are one piece and these are known as monolithic flash drives. These are the same technology as the micro SD cards, as well as the most difficult and time consuming to prepare for recovery.

The message you will get can be similar, or identical, to the one where the controller chip has malfunctioned. It depends if the data leads, or the power leads, have been broken from the PCB.

If your USB stem or flash drive is not physically broken

In the event the stem and everything is in tact, it will likely be a failed controller chip as the culprit. At this point, you’re going to need some very expensive advanced specialty data recovery hardware, and then the knowledge to operate it.

The first step would be removing the chips, or soldering wires (depending on form factor), in order to get a dump from the NAND.

Then a trained engineer will begin the process of determining and reverse engineering the encryption and error correction. Sometimes this has to be done manually and can take a long time. It’s a very complex process.

Some flash drive controller chips are not compatible with even the most current cutting edge technology. Developers have to focus their resources on the compatibility with the most common make and model of flash drives and chips.

This type of recovery is extremely difficult, because the manufacturer of these flash drives uses different chip types, even on the same model and size flash drive. What ever is cheaper and more efficient, and available, will be used.

There are thousands and thousands of controller and storage chips. Endless configurations of encryption, and error correcting, as technology increases. Additionally the companies who make flash storage memory do not share their technology, for this process, as it’s proprietary.

Can I fix a flash drive not recognized error myself?

Unfortunately, the only way to recover data from a flash drive that is not being detected is to have special equipment. Not only is it mandatory to have the equipment, but it’s just as pertinent that there be an engineer that has the knowledge to use it.

Soldering skills are very important here, as the memory chips (NANDs) will need to be removed from the PCB board. This is required so they can be read via a special reader. This is called making a dump of the chip.

There are certain temperatures, that when exceeded can damage the memory chips, or other components. It’d easy to render the flash drive unrecoverable during the removal process.

After all the chips are removed and read, then the process of determining the XOR and ECC is begun. This can take anywhere from 15 minutes, to months.


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