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. Ensure your Fiber Jack is connected to the network and the LED lights are connected and working properly before moving. Troubleshoot your router's red light with these steps. Fortunately, diagnosing and resolving these issues doesn't have to be. However, a common concern among users is a router flashing red. We will explore common reasons behind the solid red.