This issue is not a sign of a lost cause. In the vast majority of cases, it points to a firmware or controller-level problem that can be resolved with the right tools. The most common and effective solution is a process known as "mass production," or "量产" (liang chan), which involves low-level formatting the drive and reinstalling its firmware using a specialized tool.
Once the drive is stabilized in Test Mode, you can attempt to re-flash the microcode using specialized mass production tools available on developer databases like the Alcor Micro USBDev Repository .
Otherwise, follow the driver override steps above, and you will turn that "Unknown" device into a working storage drive.
This specific state is a notorious symptom among flash drives utilizing Alcor Micro controller chips (such as the AU6989SN-TA or AU6989SNCS-TA series). This comprehensive guide analyzes why this error happens, what the firmware codes mean, and how to safely determine if your drive can be saved or if it has met its end. What the Error Codes Mean alcor micro unknown fa00 fw fa04 hot
Identify the data pins connecting the controller to the rectangular NAND memory chip.
Click Setup (S) . If prompted for a password, leave it completely blank and hit enter.
Alcor Micro AU9410-based USB 3.0 hub, connected to laptop via USB-C adapter. After connecting a high-power external HDD, hub became hot to touch, disconnected, and re-enumerated as “Unknown USB Device (Device Descriptor Request Failed)” with PID FA00, FW FA04. Cooling down for 10 minutes restored normal operation. Permanent fix: used externally powered hub. This issue is not a sign of a lost cause
On Windows:
Partition Table Loss: The "low-level" format of the drive has been wiped.
: This is a generic status code often meaning "Unknown Device" or "No Flash". It usually occurs when the controller (e.g., ) is detected, but the NAND flash memory chip's ID ( ) cannot be read. Once the drive is stabilized in Test Mode,
If the device is hot, unplug it immediately. Leaving it plugged in can damage your motherboard’s USB ports or cause permanent data loss on the drive.
The corrupted firmware forces the controller engine into an infinite, resource-heavy processing loop with no power-saving idling. (Fixable via mass production tools) 3. Step-by-Step Diagnostic Check
The tool cannot fetch a valid chip ID (such as AU6989SN-TA). The hex code FA00 is a generic fallback flag representing a "No Flash ID" (No FID) error or a completely unreadable hardware state.