Could this be lightning damage?

I had something strange happen to me over the weekend. Overnight between Sat and Sun, we lost some of our LAN at home. I have (simplified) the following setup:


ADSL router -------- IP telephony DECT
                   +------- Powerline transmitter ------/ /---------------------------- NAS
                   +------- Set-top box                                                  +-- laptop
                   +------- Netgear 5-port switch                                    +-- WiFi AP
                             +--- RPi running PCP Logitech Media Center
                             +--- DVD player
                             +--- Humax
                             +--- Squeezeplayer

The ADSL router provides WiFi cover for one part of the house, the other AP for the rest. The ADSL router also has a connection for a landline telephone through built-in IP telephony.

What broke overnight was everything connected to the router via cable. The landline and all Ethernet connections stopped working. WiFi and the ADSL connection was fine.

For us, it was quite a problem since we lost our landline and all internet on one side of the house (where the study is...), as well as the ability to access the NAS for taking back-ups and all media playing dependent on the PCP.

I tested all sorts of things, disconnecting, rebooting, resetting to factory settings, etc. In the end, I got the ISP to send me a new router. What do you know, same problem. This time, however, the landlline was working; the Ethernet LAN connections were still not. But, I noticed that the LAN ports would work for about 30-45 seconds after being reconnected, then they would stop working. This puzzled me, so I did some more systematic testing. I then noticed that if I unplugged just the Netgear GS105v5 switch, the other LAN ports would work.

Now I am left to wonder - we had a bit of lightning over the last few days and nights. Could this have affected the power supply of the Netgear switch, or the switch itself, such that it would in turn disturb the router? I tested the PSU for the Netgear and it seems to supply 11.93V DC, more or less as it should. I can't think of another way of explaining what happened. Since the GS105 is a cheap unit, it is not a big deal to replace, but I hate unresolved mysteries...

Yes it does sound like a lightning or power surge or similar lighting related event has caused damage, especially if it has affected everything on the cabled side of the network.

Lightning strikes don't always have to involve massive and spectacular destruction (although I have had the displeasure of that...). A nearby strike can be enough to cause a ground potential difference/rise, which in itself can lead to equipment destruction as much as a direct strike can.

I would recommend that you try and mitigate by fitting proper surge protective device on your incoming mains - by that I mean I properly rated, fitted by an electrician Type 1/2 /3 surge protective device with indication when it is operative and not - not the plug in garbage from Amazon or fleabay

Secondly consider isolation/surge protection and how to protect also your line side (DSL) as it will be another route to electrical surges and strikes coming via the telephone network.

Thirdly avoid using any data cabling outdoors or between buildings. You don't look like you have this, but again I can tell you from my experience in industry and personal experience what a terrible idea this can be in the wrong part of the country.

Good luck with the repairs and reinstatement.

In reply to a post by Pheasant:

fitted by an electrician Type 1/2 /3 surge protective device with indication when it is operative

Am interested in this do you have any links to products or info

Sparks recommended this firm:
https://www.surgedevices.co.uk/

We have various of them fitted. I can find specifics later.

From what you've said it does sound like the fault lies with the Netgear switch or PSU. It may well be lightning damage, or could just be coincidence.

One thing I've sometimes found is that although the PSU voltage may seem fine with no load, as soon as it starts drawing current (ie you've connected it to the switch) the voltage drops down. Or the voltage could be fine but it isn't able to supply enough current.

To rule it out, you could try getting an ethernet coupler like this: https://www.screwfix.com/p/philex-cat-5e-rj45-couple... and connecting the cable from the router directly to one of the cables that go from the switch, then seeing if that particular device is working. Repeat with each other device, and if they're all good then you've proven a faulty switch. Good luck.

Have you tryed new ethernet cable to see if fix thing? I double it would but it would be a very cheap option.

Also if this devices are still not working would it be worth the hassle with making a claim on household insurances? They might make use of the "act of the god" nonsence, some will say that whilsed others wouldn't.