Zyxel XS1930-12HP: Some Ports Power PoE but Never Establish Link-Up

xfzhao

Hello,

I have an issue with my Zyxel XS1930-12HP where two of the ports are not working properly, and I could use some help identifying the cause and how to fix it.

Problem Description:

Two of the Ethernet ports do not establish a link when a device is connected — the link never goes up. However, when I connect a PoE device, the port still provides power but never negotiates data link up.

I am currently running the latest firmware version V4.80(ABQF.4) and the hardware version is V1.2.

This issue has been reproducible since earlier firmware versions. What seems to trigger the problem is when a port repeatedly goes link-up/link-down due to frequently changing connected devices. After some cycles, that port loses the ability to establish a link and stays dead even after a reboot.

In older firmware versions, I could recover the port by holding the Restore button for 30 seconds, after which the port would work again. But now even after a 30-second Restore, the port still does not work.

There is one unusual behavior: after power-cycling the switch (unplug and re-plug power), during the boot sequence the affected port can briefly link up, but once the switch has fully booted, the port stops working again and cannot be used for network traffic.

What is the problem, and how can I fix it so my switch is working properly again?

Zyxel_Melen

Hi @xfzhao

This is a known issue and we can provide you a date code firmware to fix it. I will provide it to you via private message.