Different factors can cause your router's red light to blink. This can be due to a misconfiguration, a loose cable connection, outdated firmware, a service outage, or other issues. When it's green and steady, everything is fine. However, when it blinks red or stays solid red, it signifies a Loss of Signal, a problem preventing your router from communicating. Fiber optic networks are celebrated for their speed and reliability, but even the best systems can encounter problems. This guide will walk you through diagnosing and resolving common. That blinking red LOS light means your router has lost its connection to your internet provider's network. Before you panic or call tech support, there are several simple fixes you can try at home that often solve this problem in minutes. 🔴 What the LOS/OPTICAL Red Light Means: • Blinking Red: No.