| Symptom | Possible Cause | Solution | |---------|---------------|----------| | “Invalid firmware image” | Wrong file for your hardware version | Double-check the file name. Some units require a specific “Telco” version. | | Router stuck with blinking lights | Interrupted flash or corrupt file | Perform a factory reset (press and hold reset pin for 30 seconds). Then try a USB emergency recovery (advanced). | | Cannot access web interface after update | IP address changed or boot loop | Manually set PC IP again. Ping 192.168.1.1 . If no response, contact ISP for recovery tool. | | Wi-Fi not working | Driver mismatch in new firmware | Factory reset via hardware button, then reconfigure from scratch. |