Check PoE Budget: Ensure the PoE switch or injector has enough power budget to support all connected devices. In a basic PoE power supply system, the major components are the power sourcing equipment (PSE), the powered device (PD), and the PoE cables. We have IP Cameras and Cisco APs being powered by this switch. It powers up with an A/C adapter just fine. So, I was thinking it was a PoE issue. However, when PoE fails, it can disable critical infrastructure like IP phones, wireless access points, and security cameras. Despite its convenience, PoE can sometimes fail or behave. Power over Ethernet (PoE) is a convenient technology that enables network cables to carry electrical power, eliminating the need for additional wiring. Here are some common PoE issues and how to troubleshoot them: 1.