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 This can be due to a misconfiguration, a loose cable connection, outdated firmware, a service outage, or other issues. Fortunately, diagnosing and resolving these issues doesn't have to be complicated. In this comprehensive guide, we will walk you. This guide will walk you through what the LOS light means, why it blinks red and step-by-step instructions on how to resolve the issue, including resetting your router. What Does the LOS Light Indicate? The LOS light on your router indicates the status of your internet connection to the Internet. When your router displays a red light, it can be due to several reasons.