I have a TL-SG1024S 24 port switch and I'm having an odd issue. I'll add that we've recently had severe storms and a month ago part of my LAN got messed up by lightning. (Not a direct strike, but several devices were bricked.) This switch had no problems then, but it's been acting up today. We did have some storms this weekend, but nothing else is acting up. I have not, ever, tried to do anything with my switches other than just plug ethernet cables into them. So no managing or anything else.

Basically, at times, my LAN dies. Devices say, "Cannot detect any network," or similar error messages. Several times when this has happend, I've gone downstairs and the lights on every port of my switch have been blinking on and off in unison. One time I power cycled it and things were okay. But after a while, it's gone back to blinking.

Last time this happened, I pulled out an extra switch, a TL-SG1016D, a 16 port version of the same switch. I got everything all switched over, spending about 30 minutes on it, checking what connections I could ignore (I don't use wifi with non-mobile systems) and making sure that everything was working. When it was done, I went upstairs and just before I sat down, thinking I was safe, the TV picture froze. (I use an Apple TV that gets its signal from a tuner that connects to my LAN and the error was "Can't find tuner.") Then I try pinging and find that almost everything is gone (other than a few devices in my study that are all connected to a smaller 8 port switch in the room).

Now, there's one other factor: I have a new Raspberry Pi system on my LAN. It's also using wif, so it has an ethernet and wif connection. I haven't mentioned that yet because I wanted to describe the behavior of the switches first. So I'm about to talk about the last two LAN outages, but adding in the PI. I've had an ssh connection between that and my desktop and I've had a VNC connection open during the day, on and off, so I can work on the Pi while at my desktop. At first I thought that, somehow, the VNC connection was wonky, since things seemed to go bad while that was up. I'd kill it and soon I'd get my LAN back.

But this evening the LAN has gone out even when VNC wasn't up. Tonight when the LAN went out, I pulled the network cable off the Pi and that's when I went down and moved all the cables to the 16 port hub. When I came back up and things were okay, I stopped by my hobby desk and reconnected the Pi to the network. I went to sit down and that's when the TV lost connection with the tuner - right after I pu the Pi on the LAN.

Timing is kind of weird on this, but, several times, pulling the Pi off ethernet fixed things and then the LAN went down soon after I plugged it back in.

I'm wondering if a device could, somehow, be overloading the system. I use a DHCP server and a static IP for all my non-mobile systems and I've seen no evidence that it's an IP address issue.

What do the LEDs flashing in unison mean? And could it be due to the network being overloaded from a device? Or is it more likely a sign of damage or issues in the switch?