Disassembly of Non-Standard PoE Switches

Non-standard PoE switches, also known as passive PoE switches, can be disassembled with care, but require attention to always-on voltage and internal components.

Understanding Non-

Standard Po

E SwitchesNon-standard PoE switches deliver constant voltage over Ethernet cables without performing negotiation with connected devices, unlike standard PoE switches that follow IEEE 802. 3af/at/bt standards and include a PoE control chip for safe power delivery.

Passive Po

E switches typically provide 48V or other fixed voltages directly to the powered device (PD), which means the internal circuitry is simpler but carries a risk of damaging non-PoE devices if mishandled.

Safety Considerations

Before disassembly, ensure the switch is unplugged from both power and network connections.

Non-standard Po

E switches can still carry residual voltage, so using a multimeter to verify zero voltage on the Ethernet ports is recommended. Wear insulating gloves and avoid touching exposed traces or capacitors that may retain charge.

Tools Required

Common tools for disassembly include: Precision screwdrivers (Phillips and flathead) for opening the casing Pliers and tweezers for handling small componentsPry tools or spudgers to separate plastic clips without damaging the enclosureMultimeter for voltage testing and continuity checksDisassembly StepsRemove the outer casing: Unscrew all visible screws and gently pry open the metal or plastic housing. Many switches have metal shields around the PCB that may require careful bending or unscrewing.

Identify the PC

B and components: Inside, you will typically find a main PCB with Ethernet transformers, PoE power circuitry, and port connectors.

Non-standard Po

E switches often lack the PoE control chip found in standard switches. Inspect power circuitry: Passive PoE switches usually have voltage regulators, fuses, and MOSFETs that directly feed power to the Ethernet pins. Avoid shorting these components.

Remove individual components if needed: Use pliers or a soldering iron to desolder components for repair or analysis. Take note of pinouts and traces, especially for PoE Mode B, which is commonly used in passive switches. Document the layout: Photograph or sketch the PCB layout to ensure correct reassembly.

Key Differences from Standard PoE SwitchesNo handshake protocol: Power is always-on, unlike standard PoE which negotiates voltage. Simpler internal design: Fewer ICs and no PoE control chip. Higher risk of device damage: Connecting a non-PoE device to a passive switch can burn the device.

Limited Po

E modes: Passive switches often support only PoE Mode B, while standard switches support Mode A, Mode B, and 4-pair PoE.

Conclusion

Disassembling a non-standard PoE switch is feasible with proper tools and safety precautions. Understanding the always-on voltage, internal PCB layout, and lack of PoE negotiation circuitry is crucial to avoid damage or injury. For hands-on guidance, teardown videos of similar PoE switches, such as the TP-Link TL-SG1016PE, provide visual reference for internal components and disassembly techniques.