Dear @Cogswap,

Hello, after looking at many switches because there was no network in a factory, I could see that ports 18 to 24 were failing in that switch, as if that module had failed. 1 to 17 works fine. Have you ever had several ports stop working?

To troubleshoot if the switch port is broken, you could try the following test on the physical switch:

1. power on the switch, disconnect any cable if there is

2. use a good quality cable to connect two Ethernet ports

    a. one working port and one non-working port, port 1 and port 18 for example

    b. two working ports, port 1 and port 17 for example

    c. two non-working ports, port 18 and port 20 for example.

3. check whether those two corresponding Ethernet lights will light up.

Besides, are you using the provided power cord to power up the switch? Is the power supply 100~240VAC, 50/60Hz?

With the switch powered on, press and hold the reset hole for about 8 seconds, would you see all LEDs including port 18-24 light up once?

Would you please also try upgrading the switch to the latest firmware <TL-SG2424_V2_150714> and check it helps?

Download link for the TL-SG2424 V2, https://www.tp-link.com/en/support/download/tl-sg2424/v2/#Firmware