The (also known as the PS2307 ) is a high-speed USB 3.0-to-Flash controller. When a drive with this chip becomes corrupted (e.g., "Write Protected" or "No Media"), specialized firmware update and mass production tools are required to restore it. Recommended Tools for PS2251-07
By following this guide—identifying your controller correctly, matching the firmware version, running as administrator, and respecting the formatting process—you can breathe new life into dozens of USB drives that would otherwise end up in a landfill. Phison Ps2251-07 Firmware Update Tool