I just moved in to a rented house here in Georgia two weeks ago. Last night we had a pretty bad thunderstorm and around 6PM I was sitting at my computer and we experienced a really close lightning strike. I can't find any obvious damage on the house and nearby trees that would indicate a direct hit, but it was a ears-ringing, house-shaking, everything-flashed white close hit. My computer and all electronics rebooted, but I remember hearing a distinctive metal "ping" (something like a BB hitting sheet metal) coming from my metal-enclosure router. Amazingly my computer works, and so does the Comcast cable modem, but my router (an Alix board in a metal enclosure), switch, and the onboard NIC on my desktop are all dead. My desktop doesn't even see the onboard NIC on the PCI bus anymore.
So I've ordered a PCIe NIC for my desktop and new switch and router. My (Comcast) modem still seems to be working fine.
I'm looking for input on what I can to do prevent this from happening again, and also some input on the current grounding of my CATV system (which as far as I can tell was done by Xfinity). Some pertinent details:
My theory given the proximity of my desk/network HW to the CATV service drop, and that the only damage in the house is to equipment connected to the same router as the cable modem, is that the surge entered through the CATV line and somehow jumped to the ethernet cabling without harming the modem?
I'm a software developer and spent a few years doing datacenter and commercial networking and cabling, but this residential stuff is way different from that. I've also never had lightning-related damage before.
Does anyone have any thoughts on whether my theory of CATV lines as the surge entry point seems right, and whether the possibility of a bad (or nonexistent) ground for the CATV could contribute to the problem?
Lastly, any suggestions on how to protect my computer and the replacement router and switch? My current plan - which admittedly seems like overkill and maybe misplaced - is to move the cable modem off of the surge protector and to a different circuit in the house, and then connect the cable modem to my router with a pair of fiber media converters... so the cable modem has no conductive path to any of the other electronics, other than back through the mains wiring to the panel, and then to the circuit that the computer is on.
I know this has been a long post, but I've been researching for most of the last day and I'm really outside my area of knowledge here...
I've seen lightning strikes do some funky stuff, just like you experienced. Some stuff survives, others not so much. You seem to have a pretty good understanding of bonding/grounding. The idea is to equalize the potential between the coax system and your home's electrical system. Even a properly bonded coax system won't protect you in the case of a lightning strike, that is not its purpose. You want a 75 Ohm surge protector to guard against lightning strikes. With that said, a 40-50 foot ground wire off the block would not be up to code. If the system is not grounded/bonded correctly then Comcast may compensate you for your damaged equipment. It's their responsibility to install the ground properly. At the very least they can replace the old/corroded wiring.
I've asked a Comcast employee to help you. You should expect a reply in this thread.
I can help by starting a damage claim. Can you please verify your first and last name, full street address, and the phone number or account number associated with your services in a private message?
To send a private message click on my name "ComcastChe", then click private message me.