ESP32-POE no PoE function

[Adamanter]

Hello,

I bought 10x ESP-32 POE and nine are working fine, but 1 looks faulty, because
it does not power up, when I connect this one to my PoE Switch. But when I connect this one to a normal ethernet Switch and power it with micro USB, the board works normal and I can connect via ethernet. It looks like, that only the PoE funktion is not available. Is there anything I can do?

[LubOlimex]

It can be anything. We empirically test every ESP32-POE board manufactured with PoE powering. But ESP32-POE is easy to get damaged since the PoE and USB are not insulated. If you had ESP32-POE and any device with own power supply attached together, the board might get damaged. We've also found that some very cheap network equipment with poor power supply can damage ESP32-POE over the Ethernet when USB is present and even when PoE is not enabled, we measured 40-50V DC between Ethernet's GND and USB's GNB. Also:

- measure the voltage between the grounds of all hardware pieces before connecting them;
- consider having USB-ISO between the USB and the board (or similar USB isolator), this would eliminate possible influence between USB and network equipment; make sure your switch uses good power adapter with proper transformer;
- be careful with the surface you place the boards on during testing, some surfaces are conductive (also the ESD plastic bags are conductive);
- be aware of electrostatic discharge, try using ESD strap when handling the boards (the boards have ESD protection, but still some serious discharge can damage them); we handle bare boards with gloves and use anti-static mats to place them over;
- consider switching to ESP32-POE-ISO if many ESP32-POE boards get damaged in your hardware setup;

If it was me I'd first test with another cable, then with another switch.