PoE Device Not Powering: Installer Fault Guide

First determine whether this is a power fault or a network fault

If the endpoint does not power at all, start with PoE detection and cabling. If it powers but has no IP connectivity, continue into VLAN, DHCP and network troubleshooting after the power path is stable.

Fault sequence

1. Verify the PD's published PoE requirement.
2. Verify the port supports the required IEEE type and is PoE enabled.
3. Read the switch port PoE state, class/allocation and fault messages.
4. Check total switch PoE budget and power-supply state.
5. Try a known-good short patch lead directly at the switch if practical.
6. Test the installed cable path and all four pairs.
7. Inspect patch panel and jack terminations.
8. Return the endpoint to the installed path and confirm stable operation under normal load.

Do not bypass detection with an unknown passive injector

Passive power products do not necessarily perform IEEE detection/classification. Only use them when the endpoint manufacturer explicitly specifies the voltage, polarity and connection method.

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