A TP Link Deco flashing red light usually indicates that your Deco unit is having trouble connecting to the internet or communicating with the main Deco network. This issue can happen because of an internet outage, loose connections, router problems, firmware issues or incorrect network settings. Before replacing your Deco system. try the following solutions. What Does a Flashing Red Light Mean? A red light on a TP Link Deco generally means there is a connection problem. The