If your Cisco switch PoE is not working, the most common causes are an exhausted PoE power budget, a disabled inline power configuration, physical cable faults, incompatible powered devices (PD), or a crashed PoE controller. When a problem occurs with PoE, in most cases, the error symptom can be simply shown as the PoE switch not providing power, and the powered devices will stop. This article provides troubleshooting information for common Power over Ethernet (PoE) problems with NETGEAR PoE switches. PoE is a networking feature defined by the IEEE 802. 3af. How to accurately identify the source of PoE errors and minimize PoE troubleshooting time? This article will detail three common PoE faults and troubleshooting methods for Power over Ethernet. PoE PD failure to start is one of the most common errors in PoE failures, usually caused by PoE component. Power over Ethernet (PoE) simplifies device deployment by delivering both data and power over a single Ethernet cable. However, when PoE fails, it can disable critical infrastructure like IP phones, wireless access points, and security cameras. Insufficient Power Delivery. Lower end PoE models - 108F, 124E/F-FPOE, 148E/F-FPOE. Since the beginning of the year we have had to RMA about 35-40 of them due to Power Fault Error Types 17. A diag switch-controller switch-info poe sum gives the below error on every port when we have an issue.