| Problem | Likely Cause | Solution | |--------|--------------|----------| | "File not found" | Wrong filename or USB format | Rename to exact filename required (check manual); reformat FAT32. | | Update stalls at 0% | Incompatible firmware version | Re-download firmware for exact model and (e.g., U160 vs U160-M). | | Device won’t boot after update | Power loss or wrong firmware | Recovery via TFTP (Method C) or contact support for boot repair tool. | | Fingerprint accuracy drops | Sensor calibration lost | Re-enroll a few users; perform sensor auto-calibration if available. |
The location of this feature depends on the model of your ZKTeco device (Fingerprint standalone vs. Face/Terminal): zkteco firmware update