[geeks] Whee! Lightning strikes, AGAIN!

[Barry Keeney]

On Wed, 29 Jul 2009, Lionel Peterson wrote:
> 
> I think my hardware was killed by an EMP, because the computers work
> fine, except the NICs - every NIC (save one, so far) that had a wire
> of any length attached to it is DEAD. A power surge would have taken
> out the computer AND the NIC, but that didn't happen. The two TVs that
> were hit are CRTs, the flat panels (actually rear projection and
> plasma) are fine. I suspect the CRT somehow "collected" enough energy
> to kill the set. The garage door opener and A/C controller had
> electronics that weren't very well protected (compared with, say, a
> sealed up, grounded, PC chassis).

  It could be that the flat panels have better power supplys that
protected them more then the (older?/cheaper) CRT TV's. 

> The dead switches, router, and cable modem all power on, but have dead
> NIC ports, again, discounting the idea a power surge came in the power
> line in my mind. 

  Well it's still possible that the surge entered from the power grid
and moved to the network devices via a poorly designed device(s) (switch,
router, etc) that allowed the surge passed it's power supply to the
network cables.

  But this got me thinking, If EMP caused the problems then the phone
wires in your house would have been effected as well. They would have long
runs in the house. So I work with a large number of phone guys, from
installers all the way up to phone switch operators, so I call one up. In
his 15-20 years working in the phone industry he hasn't seen anything
about protecting equipment from EMP. Everything is to protect from damage
from direct strikes. But they ground *EVERYTHING*. Everything outside 
will be shielded and have lots of grounds alone the cable path, but that
ends inside the building. From the jumper blocks to the final jacks
are generally unshielded, just like normal network cables. The lines have
protection equipment (he described them as kinda like fuses) but not on
the last length to the phone. The protection devices on the copper lines
fail so rarely he couldn't remember replacing one.

  If EMP was a likely cause for damage we would see more damage here at
work from lightning and we have 10,000+ phones. We would be replacing more
phones/fax machines/modems/etc after storms and we don't see that pattern.
We're also in the state with the second highest lightning strikes in the
US and at a size of 40+ square miles it's not like we don't get hit
either. I've seen a few lightning hits on site in the last week alone.

  I'm not saying it wasn't/couldn't be EMP, but I would think it's less
likely then something else everything had in common, like the power grid.

  Now for something useful, I've seen Lots of suggestions so far, but I
haven't seen his yet:

  Have you checked your local state/county/city/town government to see 
if they might have a program to help locate how the surge is getting in? 
Your power company might have a program as well. 

  If you can get someone (hopefully an expert) to take a look you would
have a better idea of what, or how, to better protect your equipment. 

Barry Keeney
Chaos Consulting
email barryk at chaoscon.com

"Rap is Square Dancing gone terribly, terribly Wrong...." 

"Michael Jackson has touched so many, and I'm not just talking about the children......"