The drive shows up as an "Unknown Device" in your Device Manager. The device requires formatting every time you plug it in. The storage capacity displays as or an abnormally massive/incorrect size. 2. Immediate Diagnostic Steps
AlcorMP is the standard factory utility used to revive Alcor-based USB drives. It rewrites the firmware directly to the controller chip.
Older laptops may have handshake issues with the internal USB hub. A BIOS update can include new USB module firmware. usb device id vid 058f pid 1234 full
If the device is write-protected, it may be due to a physical switch on the drive or a firmware-level lock.
Every USB device uses a 16-bit Vendor ID (VID) and Product ID (PID) to negotiate driver mapping with the host computer's operating system. The drive shows up as an "Unknown Device"
Download a specialized hardware diagnostic tool such as or ChipGenius from specialized repositories like USBDev . Insert your drive and run the tool to obtain an analysis report like this:
Last updated: October 2025 – Verified against Windows 11 23H2, Ubuntu 24.04, and macOS Sonoma. Older laptops may have handshake issues with the
To restore a drive with these IDs, you must typically reflash the firmware using "Mass Production" (MP) tools specifically designed for Alcor controllers. Alcor Micro - USBDev.ru
0 MB on a 32GB USB stick - Storage Devices - Linus Tech Tips
: Many cheap, unbranded "no-name" USB drives use low-grade Alcor clone chips configured natively with this generic identity string. Diagnostics: How to Read the Flash ID
