The POE swtich don't work, what to do?

When the POE switch encounters problems, 1. Check whether the indicator light is yellow (POE power supply indicator light) and the green light (network signal indicator light) flashes; 2. Do not power off, hot plug first to see if it will be OK; 3. Power off and restart whether it will be ok; 4, Change a front-end device; 5, change a network cable (whether the crystal head of the network cable is well fixed, whether it is connected according to the 568B line sequence, whether it is shielded wire, if it is used, it can be used only after grounding); 6, change a PoE switch. If it's not good enough, change the POE switch to another place and use it to judge whether the switch is good.