Diagnosis: The LED indicators for Power, WAN, LAN, 2.4GHz, 5GHz, and 2.5G can be disabled.
Fix: Locate the LED on/off button on the front panel of the router. Press it once to turn off all LED lights. Press it again to turn them back on.
If that didn't work: Ensure you are pressing the correct button. It is labeled as the "LED on/off button" on the router's diagram, not the WPS button or the Power button.