If your router is on, as indicated by the blue light, but you can't access the internet, the best way to resolve the issue is to perform a hard reset. This process clears all caches, refreshes the RAM, and restarts the router. Typically, these lights correspond to various router functions such as power. The tables in this article provide detailed information about the possible appearances of the LED lights on each device, the possible causes of each state, and what you should do. Ensure your Fiber Jack is connected to the network and the LED lights are connected and working properly before moving. The LEDs on your modem, optical network terminal (ONT), router, or modem/router combo (gateway) are most likely blinking because they're communicating what the device is doing, or there's an error.