Some cheap, non-standard PoE devices may have weak protection circuits. This can cause an overload and burn out the power supply chip. The cause of failure may be attributed to many factors, including hardware device factors and software factors. How to precisely. Power over Ethernet (PoE) switches are essential in many network setups, providing data and power over a single cable. This article will walk you through troubleshooting PoE switch. As for modem/router burned out by PoE, unless you are doing some cable modding it shouldn't happen. However, PoE setups can encounter various issues. Insufficient Power Delivery. POE switch does not supply power Cause analysis: The device does not support POE power supply: The powered device itself does not have the POE power receiving function, or the device is incompatible with the POE standard of the switch.