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.
If you’ve just plugged in a USB flash drive, an SD card reader, or an MP3 player and found yourself staring at a device manager entry labeled "Alcor Micro Unknown Device" with Hardware IDs mentioning FA00 or FA04, you are not alone.
Even more concerning is that you might notice the device is running physically hot to the touch, despite not being accessible by Windows.
This is a very specific issue related to Alcor Micro (AU) USB controller chips. In this post, we’ll explain why this happens, how to identify the chip, and the steps to fix the "Unknown Device" error.
Dealing with specific firmware versions like FA00 and FA04 for Alcor Micro devices requires a methodical approach. By understanding the role of firmware, updating when necessary, and troubleshooting common issues, you can often resolve problems and improve the performance of your device. If you're still experiencing issues, consider reaching out to the manufacturer's support team for more personalized assistance.
Here’s a concise draft feature entry you can use (e.g., bug tracker, release notes, or issue report) for the Alcor Micro unknown FA00/FA04 hot condition.
Title Alcor Micro USB controller: Unknown FA00 / FA04 — device running hot
Description Some devices using the Alcor Micro USB controller report the controller enumerating with unknown vendor/product codes FA00 and FA04 and exhibiting excessive heat during operation. This issue covers detection, impact, and suggested mitigations.
Symptoms
Affected components
Impact
Reproduction steps
Diagnostics to collect
Probable causes (hypotheses)
Short-term mitigations
Long-term fixes
Suggested next actions
Acceptance criteria for resolution
One-line summary Alcor Micro controllers enumerating as FA00/FA04 and running hot — collect device logs and thermal data, advise backups and limited use, pursue firmware/hardware replacement through vendor.
If you want, I can:
This issue typically indicates a hardware failure or a critical firmware mismatch in your USB drive's Alcor Micro controller
. When a drive shows as an "Unknown Device," displays an "FA00" error code, and becomes physically hot, it usually means the controller chip is either short-circuited or stuck in an infinite boot loop due to corrupted firmware. Core Problems Identified FA00 Error / No FID
: This code often appears when the controller cannot communicate with the NAND flash memory chip (the part that actually stores your data). Overheating
: Rapid heating is a sign of an electrical short or the controller drawing excessive power while trying to initialize failed hardware. Firmware Mismatch
: The "FA04" or "FA00" designations are internal Alcor status codes indicating the controller model (like the AU6989SN-TA ) is not properly identified by standard drivers. Recovery and Fix Attempts
If you want to try and "revive" the drive, follow these steps, but be aware that physical heat often suggests the hardware is permanently damaged.
Understanding the Alcor Micro "Unknown FA00 FW FA04" Error: A Troubleshooting Guide
If you’ve plugged in a USB flash drive only to find it unrecognized, or if you’ve gone digging into hardware IDs and found the strings "FA00" or "FW FA04," you are likely dealing with a corrupted Alcor Micro controller.
This specific error state—often appearing as "Unknown Device" or showing incorrect capacity—usually indicates a firmware (FW) mismatch or a "handshake" failure between the controller chip and the NAND flash memory. Here is a deep dive into what this means and how to fix it. What is Alcor Micro FA00 / FA04?
Alcor Micro is a major manufacturer of USB flash drive controllers. When a drive is functioning correctly, it reports its real capacity and brand name. However, when the firmware becomes corrupted—due to improper ejection, power surges, or NAND wear—it enters a "Test Mode" or a generic state.
FA00 / FA04: These are hexadecimal status codes or partial firmware versions used by the controller during its boot sequence.
"Hot": In the context of flash drive repair forums, "hot" often refers to a "Hot Plug" method or a trending firmware fix for a specific batch of chips (like the AU6989 series) that recently hit the market. Common Symptoms
Write Protection: You can see your files, but you can’t delete or add anything. alcor micro unknown fa00 fw fa04 hot
Zero Capacity: The drive shows up as a "Generic USB Hub" or "Unknown Device" with 0 bytes of space.
LED Blinking: The drive's light flashes rapidly but never initializes. How to Fix the "Unknown FA00 FW FA04" Error
To fix this, you generally need a Mass Production Tool (MPTool). This is specialized software used in factories to "burn" the firmware onto the controller. Step 1: Identify Your Controller
Before downloading tools, you must know your specific chip model.
Tool: Download ChipGenius or Flash Drive Information Extractor.
What to look for: Note the Controller Model (e.g., AU6989SN, AU6989AN) and the Flash ID (a long string of letters and numbers like AD DE 94 EB). Step 2: Find the Right AlcorMP Version
Alcor Micro controllers are very picky. A tool meant for an "AU6989" might not work for an "AU6989SN-GT." Search for "AlcorMP" followed by your controller model.
Look for versions that mention support for FA04 or FA00 firmware specifically. Step 3: The "Hot" Recovery Process (Low-Level Format) Run as Admin: Open the AlcorMP.exe as an administrator.
Insert the Drive: If the tool doesn't see it, you may need to use the "Driver" tab in the software to install the Alcor bus driver. Setup/Configuration: Click "Setup." (The password is usually blank or "888888").
Under Flash Type, ensure it matches what ChipGenius told you. Under Scan Mode, select "Low Level Format" for a deep fix.
Start: Hit "Start" and wait. Do not unplug the drive. If successful, the status bar will turn green, and the "FA00" error will be replaced by the drive’s actual capacity. Why is my drive getting "Hot"?
If you noticed the drive is physically hot to the touch while experiencing the FA04 error, this is a sign of a hardware short circuit.
Firmware Loop: Sometimes the controller gets stuck in an infinite boot loop trying to communicate with a dead NAND cell, causing it to overheat.
Hardware Failure: If the drive burns your finger, software likely won't fix it. The controller or a capacitor has likely failed. Conclusion
The Alcor Micro Unknown FA00 FW FA04 error isn't necessarily a death sentence for your USB stick. In most cases, it’s a software "confusion" that can be cleared by re-flashing the controller. Just remember: using an MPTool will wipe all data on the drive.
This error refers to an Alcor Micro USB flash drive that has become corrupted and is being misidentified by the system. The "Unknown [FA00]" status indicates firmware (F/W) or Flash-Translation-Layer (FTL) corruption. 🛠️ Restoration Guide Alcor Micro AU9410-based USB 3
To fix this, you must re-initialize the controller using the factory Mass-Production (MP) software. 1. Preparation Backup: This process will destroy all data on the drive. PC Setup: Use a Windows machine with administrator rights.
Direct Connection: Plug the drive into a direct USB port on the motherboard; avoid using hubs. 2. Required Software
Download a version of AlcorMP that explicitly supports the FA00 controller, such as: AlcorMP v16.09.30.00 or newer.
Reputable sources for these tools include FlashBoot.ru or USBDev.ru. 3. Execution Steps
Extract and Run: Extract the tool to a simple path (e.g., C:\AlcorMP\) and run AlcorMP.exe as an Administrator.
Detection: If the drive is not detected, click "Refresh". If still missing, you may need to manually enter the VID (058F) and PID (6387) in the "Driver" settings. Configuration: Go to Settings (password is often blank or 1234). Set MP Mode to "Capacity optimize". Set Scan Level to "Full Scan".
Start: Click "Start" and wait for the process to complete (can take 10–60 minutes). 💡 Troubleshooting Tips
Overheating: If the drive feels physically "hot" and the software returns a Red Slot error, the hardware is likely physically defective and cannot be fixed by software.
Single Channel: If you encounter compatibility errors, try setting the Channel to "Single Channel" in the settings, though this will cut the drive's capacity in half.
If you tell me the VID and PID from a tool like ChipGenius, I can help you find a more specific firmware version for your exact hardware. AlcorMP Tool for Generic 32GB Flash Disk VID 058F PID 6387
This guide addresses issues with Alcor Micro USB controllers showing as "Unknown Device" with firmware (FW) strings like FA00 or FA04, often accompanied by the drive becoming physically hot. This combination typically indicates a firmware corruption or a hardware short-circuit. 1. Safety First: Addressing the Heat
If your USB drive is physically hot to the touch, disconnect it immediately.
Hardware Short: Excessive heat often means an internal electrical short. Continuing to power the device can permanently damage your computer's USB port or the drive's NAND flash chip (where your data is stored).
Cool Down: Let the drive cool completely before attempting any further software-based recovery. 2. Identify the Controller Details
To fix an "Unknown" Alcor Micro device, you must identify the exact chipset. Standard Windows tools often fail here, so specialized utilities are required:
ChipGenius or Flash Drive Information Extractor: Use these tools to find the VID (Vendor ID, usually 058F), PID (Product ID), and the specific Controller Part Number (e.g., AU6989SN-TA). If you’ve just plugged in a USB flash
Note: If these tools cannot see the drive at all, the hardware may be physically dead. 3. Firmware Restoration (MP Tool)
If the controller is detected but shows a "No Media" or "Unknown" status with firmware errors like FA00/FA04, you may need a Mass Production (MP) Tool to "re-flash" the drive.