The router cannot connect to the internet after the fiber optic cable is disconnected

A fiber optic router disconnection can result from cable issues, hardware faults, or configuration errors, and can often be resolved by systematic troubleshooting.Step 1: Check Physical ConnectionsEnsure that all fiber optic cables are securely connected to the ONT and router. Look for visible damage, sharp bends, or loose connectors, as even minor bends can cause signal loss. Clean the connectors with lint-free wipes and isopropyl alcohol to remove dust or oil that may interfere with the signal .Step 2: Inspect Router and ONT LEDsCheck the status lights on your ONT and router. Key indicators include:Power LED: Should be solid; if off, the device may not be powered.PON/Optical LED: Indicates fiber signal; if off or red, the ONT may not be receiving a signal.Data/Internet LED: Shows LAN/WAN connectivity; if off, check Ethernet cables between the ONT and router .Step 3: Restart DevicesPower cycle your equipment:Turn off the router and ONT.Unplug them from the power source for 10–30 seconds.Plug them back in and wait a few minutes for the devices to fully reboot .Step 4: Verify Router ConfigurationEnsure your router is correctly configured:The Ethernet cable from the ONT should be connected to the WAN/LAN port on the router.Check for IP conflicts or incorrect network settings.If your router has firmware updates available, apply them to fix potential bugs .Step 5: Test with a Wired ConnectionConnect a computer directly to the ONT using an Ethernet cable. If the internet works, the issue may be with the router or Wi-Fi settings. If it still doesn't connect, the problem may be with the ONT or the fiber service itself .Step 6: Check Power and Environmental FactorsEnsure the ONT and router are plugged into working outlets. If the ONT is connected to a GFCI outlet, verify it hasn't tripped. Avoid extreme temperatures or moisture near the devices, as environmental factors can degrade performance .Step 7: Contact Your ISPIf the above steps do not restore connectivity, contact your internet service provider. They can run diagnostic tests on the fiber line, check for outages, or replace faulty equipment . By following these steps—checking cables, LEDs, power, configuration, and testing connections—you can often identify and resolve the cause of a fiber optic router disconnection.