Ensure the file matches your hardware version (v1, v2, or v3) to avoid bricking the device. 2. Access the Admin Panel
to the "Maintenance" or "System" section and find "Update" or "Firmware Update".
The TG789vn is legacy hardware. While updating the firmware can squeeze another year of stability out of it, the best long-term solution is to migrate to a modern router. If you choose to proceed, follow the steps above precisely, use a wired connection, and triple-check your hardware revision before hitting "Upgrade."