Lightning strike

On the early hours of Tuesday morning it appears the local area suffered a lightning strike, which got into the BT network.

It's blown my trusty Netgear DGN2000 up - completely dead and it smells of burning plastic - happened to neighbours too.

No bother, i've got a DG834PN in the loft. Plugged it in and all is well downstairs.

I've got CAT5 running around the side of the house alongside a BT phone extension and on the end of it is a WNR2000 which I use as a switch / wireless repeater.

The WNR2000 was madly flashing so I turned it off. Turned it back on and my iPhone and other devices would not connect to it. Took it downstairs to the PN, plugged it in and it was fine but it won't work on the CAT5 all I get is 169 addresses and assigning a static IP doesn't work either - it's dropping packets - even if I plug my laptop directly into the CAT5, it drops packets.

The network card on my work laptop and Xbox 360 appear to be dead - these were plugged directly into the DGN2000.

Has the lightning destroyed my CAT5??

Surely it would just pass through it, there are no signs of scorching etc.

In reply to a post by wolvesmad:

Has the lightning destroyed my CAT5??

Surely it would just pass through it, there are no signs of scorching etc.

It certainly looks like it!

High-Voltage surges can do all sorts of damage that is NOT readily visible (or would smell of burning).

Have to suggest that it is a case of:- If in doubt, replace it!

The Cat5 is probably ok, a continuity tester would be needed to check the wiring, but you may have blown over voltage protection circuitry in the 360 and laptop.

Time to get a simple known working switch and see if the Ethernet link lights work.

If you've only tried them on the WNR2000 then most likely that has sacrificed itself to protect other hardware

With a 1m patch lead plugged from the DG834PN to the WNR2000 everything works fine so i'm pretty sure the WNR2000 has survived.

In the room the WNR is in, there is a Sky HD box which blew it's HDMI cable but survived.

The PSU on my older 360 blew too - it was plugged into the mains but turned off.

I'm right in thinking a surge protector would have done naff all with this kind of voltage?

Sounds like a substantial hit so time to test everything.

The surge protector might have helped, and if not so long as you comply with the insurance terms of them you are covered.

Following on from Andrew's suggestion of testing the wiring, keep in mind that if you are trying to do so with a simple continuity meter, that there are 3 Twisted Pairs, ie 6 wires.

The initial testing is simple, that each wire is continuous end-to-end.

Then you have to test that each wire is insulated from ALL of the others; and that is when a chart becomes useful, helping ensure that you have tested between each and every wire.

You also have to keep in mind that manipulating the cable and wires and connectors, to do such tests, can alter the situation, eg broken ends of a wire may temporarily make contact during testing; and a short between two or more wires may be temporarily parted - both resulting in the cable appearing to be OK; but as it is restored to its normal position, the break and/or short re-appear.

I have seen such intermittent and transients faults all too often.

Assuming the wiring run is reasonably accessible, I would recommend simply replacing the cable, if it remains suspect.

It actually blew a hole in the roof of a house a few hundred meters away. Houses in close proximity have lost literally everything electrical.

I'll see if one of the network lads at work can lend me a cable tester. The phone extension is running alongside the CAT5 at the moment.

Is it best to keep these apart?

In reply to a post by wolvesmad:

It actually blew a hole in the roof of a house a few hundred meters away. Houses in close proximity have lost literally everything electrical.

Many years ago, before we had anything like Broadband etc, my House was struck by Lightning.

Lightning is unique every time it hits & what it affects (& what it doesn't affect) is bizarre & inconsistent (***)!

You just have to work through item by item, replacing as necessary.

As I've said before:- if in doubt, replace! This will save a lot of subsequent frustrations when you find things not quite working as you expected (even if you have undertaken basic tests which are successful)!


Edited to provide the following example!

(***)
AS an example the external telephone wiring, to my house, was blown up but the internal wiring was not affected.

However, a house 200m up the road (fed from the same Telephone Pole) had his Telephone blown off the wall!

Edited by deleted (Wed 24-Jul-13 13:24:31)

I've had 3 lightning strikes on my phone line in the last 15 years. The first two times, it tooks out lots of equipment. The third time was last year, but since then I'd installed some devices similar to (but not the same) as: this (Amazon link).

I got two phone ones I think for both phone and broadband sockets of the ADSL faceplate, and ethernet ones for the ports coming out of my router. I wired the earth leads from them into a junction box and a cable coming from that terminating in a normal mains plug with only the earth pin wired, which I then plug into a wall socket.

In that last lightning strike last year, it blew up my BT master socket, fried the ends of the patch cable coming from it, but the protectors on the master socket sacrificed themselves and saved the lightning getting through to my network.

My neighbours also suffered the same lightning strike, but they didn't have protection and it blew up their router as well as the master socket. I think they're lucky!

I don't think "normal" surge protectors will protect against lightning strikes. If lightning is able to travel many miles between clouds and between cloud and ground, then it is able to jump across a gap of a couple of millimetres! You need one of these devices with an earth lead I think.

Edited by deleted (Wed 24-Jul-13 13:57:41)

In terms of lightning protection difficult to say as lightning will arc a long a way, hence how it gets out of the sky.

The induced currents from a near strike which you had then keeping cables apart may reduce the impact of any incidents.

If you had a direct lightning strike you would have a lot more to worry about than you router

In reply to a post by Bob_s2:

If you had a direct lightning strike you would have a lot more to worry about than you router

A *direct* strike might indeed blow your house up, but this thread is about a strike on the phone cable. Protecting the router ensures that it doesn't get to all your other expensive equipment and data on the network.

If you do manage to borrow a cable tester, make sure that you comprehend what it is doing/attempting to do, because of the complications I mentioned earlier.

If you are not accustomed with such testers, try to practice on some cables. including deliberate shorts and opens. Good learning opportunity!


Regarding the two cables running alongside one another, there may be mutual interference both ways, in degree undoing the work of the splitter.

The coupling reduces by the inverse square of the distance, so even a short distance apart can reduce it significantly.

Tidily bundled together and/or twisted together is the worst scenario.

Thanks for that. Looks like I will have to invest in one of those.

Did a bit more testing last night. This storm has taken a fair bit of my kit out.

Unfortunately it looks like it's fried the ethernet side of my WNR2000. If I plug just the CAT5 from the router downstairs in it works as a repeater just fine on wireless. If I plug other ethernet devices in, the port lights on the WNR come on but there is no connectivity, no ip address and assigning a static does not work either.

When I pull out the ethernet cable on Port number 4 (the port the CAT5 from downstairs was plugged into when the strike happened) the port remains lit.

So unfortuantely it appears the WNR has taken a few volts too many. Bit gutted really as it was a good switch / WAP.

The HDMI board on my surround sound system has blown and it's killed HDMI port 2 on my TV, the port the surround sound was plugged into when the strike hit.

I'm amazed the Sky HD box has survived. Plugged into the phone line and the ethernet cable, it's a miracle it hasn't died.

My commiserations, it's not pleasant.

The first time it happened to me, it took out pieces of equipment that were not even plugged into mains, it all happened to equipment interconnected by the phone line, and stuff attached to those. Answering machine, Sky box (but I ditched Sky a long time ago I hasten to add and now have Freesst - much better lol!), computer motherboard, modem attached to computer, printer attached to computer. I didn't have broadband and a network then.

I've found the protection devices I've now got:

Phone/DSL unit
Ethernet unit

The usual disclaimer: I can't guarantee that these this will work in future for you and if you have any questions about wiring them up then see an electrician!

Hope it didn't affect anything in your kitchen

How do them phone line surge protectors work? Where do you attach them and does it effect the quality of the line?

Edited by bobble_bob (Thu 25-Jul-13 16:04:34)

I haven't got a clue how they work! Presumably they have a fuse which blows instantly and the current is then redirected to the ground wire somehow. They are attached inline from the phone socket to the original plug on the phone and the ground wire must be connected to an earth somewhere - I've done it via a normal mains plug but presumably if you've got a bit of equipment nearby with an earth terminal or screw then you can use that. I'm sure there is some sort of insertion loss but I haven't noticed any problems with voice line quality - it sounds the same whether they're connected or not.