Visit a specialized firmware database site like or iFlash.ru .
Run ChipGenius and H2testw. If the real capacity is significantly less than the advertised capacity, or if the write speed is extremely slow (<5 MB/s on High Speed), the drive is likely fake.
For a generic NAND USB2DISK drive:
Another common symptom is a drive that appears in Device Manager but shows "Please insert a disk" when accessed. This can happen when:
When a flash drive's firmware gets corrupted, or when a fake capacity drive attempts to write data past its true physical limits, the controller crashes into a safe mode. It drops its brand identity (like SanDisk or Kingston) and reverts to its factory identifier: NAND USB2DISK . Step 1: Check for a "Fake Capacity" Scam usb mass storage devicenand usb2disk full
For most users:
In conclusion, USB Mass Storage Devices and USB 2.0 Disks are widely used technologies for storing and transferring data between computers. Their plug-and-play and hot-swappable features make them easy to use, while their high-capacity storage and fast data transfer rates make them ideal for a wide range of applications. Visit a specialized firmware database site like or iFlash
NAND refers to the type of non-volatile flash memory chip inside your USB drive.
Zap.
Do not guess the controller. Using the wrong mass production tool will fail and could permanently damage the drive. Use ChipGenius to get the exact "Main Controller" model, as shown in the tables above.