Thunderstorm killed nics???

[NeelyMSU]

Hi

The other day, there was a thunderstorm and it was pretty bad. I was not home, but one of my roommates said he saw lightning strike very close to our apartment. We did not lose power, but since then we have noticed that our internet has been acting up. We use a cable modem and a linksys router to split up the connection to 3 computers. So far, I had to replace my NIC and one of my roommates. I suspect that my other roommates NIC is bad too. The funny thing is that Windows sees the NICs, my NIC connects to the router and gets an IP, but it takes forever (or sometime never) to get to a website. My roommate's NIC would not even connect to the router (no lights). I swapped in a spare NIC and his machine was back up and working perfectly.

Any thoughts? Could the lightning strike have traveled through the cable modem? But if so, how come the modem and the router are ok. This is really weird. I had another machine connected, but it was not running. I swapped the NICs from that machine and they worked in the machines that had damaged NICs.

I'd appreciate any thoughts and comments.

Thanks.

 

[Texun]

Were all NICs connected to CAT5 cable at the time? This is not unusual. The theory that I have heard is that this happens due to the EMF (or was it EMI) from the lighting. The electrical charge in the air induces a momentary charge in the CAT5 cable... IF it is unshielded, and almost all CAT5 is unshielded. The charge in the unshielded CAT 5 hits and fries the port on the NIC, if your lucky. Some will take out the board.

 

[NeelyMSU]

The funny thing though is that the cable modem and router were unaffected, at least as for as I can tell. It's got me freaked out now.

Thanks for the insight.

 

[Texun]

That doesn't mean they did not take a hit, only that they survived. I see tons of dead ports after a lightning storm. Some are dead NIC's and others are dead ports on modems. All the lights can be on and lit as normal but there is usually no connectivity. It is a true case of "All the Lights Are On But Nobody's Home."

I could be wrong but I doubt it. There is a correlation with dead ports after a lightning storm and my guess is that the length of unshielded CAT5 charges up from the electricity in the air and then discharges (blows) at the weakest point. Overhead power lines will do that. Even when shut off they can still carry a lethal dose of electricity. Good luck with it.

 

[340mopar]

Somewhat related, but when I was gone for a few days last year, lighting took out only the com ports on the motherboard, yet internal modem was fine. All while connected to a APC backup ups 500. It was the 1 and only time left puters pluged when away for more than a night. Now when home and severe lighting comes close, all is disconnected especially the
PHONE JACK....
Geo.

 

[Peter]

Disconnecting stuff doesn't help much when the lightning strikes really close to your house. Especially the LAN cables that typically run along the outer walls receive a huge inductive blast, toasting all NICs in reach.

After a serious thunderstorm, you see just as many computer servicemen going from house to house with boxes of NICs as you see window replacement and roofing workers ...