PoE & cameras
Power present is only the first check.
Understand identification, power budgets and behaviour under load before replacing the camera or switch.
Is the problem power delivery or lost video?
Check whether the camera actually restarts or only loses its video stream before investigating the power supply. For a restart, compare the camera requirement with the port limit and shared switch budget. Reproduce the failing operating mode on a known-good short lead, then compare the installed run under the same conditions.
- Record uptime, switch events and the feature that triggers the failure.
- Check the camera requirement, individual port limit and total PoE budget.
- Compare the cable paths and, with suitable equipment, measure behaviour under load.
- PoE & camerasPoE voltage is present. Why does the camera keep rebooting?
Check a PoE camera that restarts when infrared lighting or PTZ movement begins, using port budgets, known-good leads and loaded measurements.
7 min read - PoE measurementPoE identification vs loaded measurement: what each result means
Distinguish PoE detection, advertised power, inline observation and applied-load testing before diagnosing a camera or switch.
6 min read
Which related test could help next?
Use the related guides to check another part of the diagnosis once the first comparison is complete. Wiring, application support and power delivery are different questions, so a result in one area may leave another unresolved. Select the next test from the remaining symptom, rather than treating every PASS as a complete answer.
- Fault findingAll eight lights pass. Why is Ethernet still at 100 Mb/s?
Separate a wiring fault from a 100 Mb/s port, a damaged pair or a configuration problem with a controlled Ethernet troubleshooting sequence.
7 min read - Tool selectionVerification, qualification or certification?
Understand what each level of network cable testing proves, which tool you need and what should appear in a cabling handover report.
6 min read
Which references support these checks?
The references below support the terminology, documented tool capabilities and external cases used in this category. Manufacturer information applies to the named instrument; a published case records another author’s observations. Follow the linked guide for the relevant scope and limitations, and use the project specification to determine any required acceptance test.