The "Online Upgrade" button often says "No new firmware found" even when updates exist. Ignore it. Instead, click the Manual Upgrade or Browse button.
Power outage during update, or corrupted file. Solution (The Emergency Recovery): tp-link archer c5 v4 firmware update
Once the router reboots and you see a solid power LED, perform a factory reset . Press and hold the Reset pinhole on the back for 10 seconds until all lights flash. Why? Because leftover configuration variables from the old firmware can cause conflicts. A clean slate ensures all new features work correctly. The "Online Upgrade" button often says "No new