The best source for these tools is often USBDev.ru, which hosts a large library of Alcor tools.
If you’ve ever plugged in a USB flash drive only to be met with the dreaded "No Media" or "0 Byte" error, you know how frustrating it can be. Often, the issue isn't the physical hardware, but corrupted firmware. For drives using the Alcor Micro AU87101A controller, the Alcor UFD Utility
This is the single most critical step. If you are unable to physically open the drive to inspect the chip, use a more reliable tool or method: au87101a ufdisk
If your drive utilizes the Alcor Micro AU87101A controller, you might need to use specialized production tools (MP Tools) if you experience the following:
The vast majority of searches for "AU87101A UFDISK" are from users encountering problems, as evidenced by the numerous forum posts. These issues typically fall into a few categories. The best source for these tools is often USBDev
Download a trusted low-level hardware scanner like or ChipEasy . Plug in your flash drive and scan it to look for the following precise fields: Controller Vendor: Alcor Micro Controller Part-Number: AU87101A / AU87100 / AU89102
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Open the panel. If prompted for a password, press Enter leaving the field blank.
When you see "AU87101A UFDISK," your computer recognizes that a USB storage device is plugged in, but the drive has "forgotten" its name and proper configuration due to firmware corruption. For drives using the Alcor Micro AU87101A controller,
during this operation. The status bar may cycle through phases labeled Analyzing, Erasing, and Writing Firmware . The total processing time can range from 5 minutes to over an hour depending on the physical capacity of your flash memory chip. Comparative Analysis: Troubleshooting Methods
If your device is not immediately listed, click the button to force a new bus scan.