Jump to content


Register a free account to unlock additional features at BleepingComputer.com
Welcome to BleepingComputer, a free community where people like yourself come together to discuss and learn how to use their computers. Using the site is easy and fun. As a guest, you can browse and view the various discussions in the forums, but can not create a new topic or reply to an existing one unless you are logged in. Other benefits of registering an account are subscribing to topics and forums, creating a blog, and having no ads shown anywhere on the site.

Click here to Register a free account now! or read our Welcome Guide to learn how to use this site.


Lightning damage learning

  • Please log in to reply
4 replies to this topic

#1 tecnoviper


  • Members
  • 1 posts
  • Local time:08:18 AM

Posted 08 September 2012 - 05:23 PM

So yester day lightning struck out my modem for a 3rd time :angry: , but this time it also did damage to my router. I have already replaced all of the damaged hardware, but out of intrest(since i am going to study electrical ingeneuring next year) would like to know more about the damage the lightning does. It most defently did fry all the components, because i could get some of the things to work(just not 100%)
Modem is a billion mweb modem (model DMW-W40)
Router is a D-Link Model DI-524 and it is connected with a 35m TCP cable to the modem.
On the modem only the 4 ports work after the lightinig struck, but the dsl port doesn't work. On the router only ports 2-4 work. Port 1 (in wich my computer was plugged) is broken(doesn't pick anything up) and the WAN port wich comes from the modem is broken(same as port 1). I opened them up since warrenty doesn't cover lightninig damage. And can'nt see any thing wrong(black burrend marks or something) so i was wondering wich componnents causes these failers and if maybe it is fixable and how it is.

PS. any advice on how to protect against lightning damage will also be of much help!

Thanx in advance

BC AdBot (Login to Remove)


#2 Sneakycyber


    Network Engineer

  • BC Advisor
  • 6,104 posts
  • Gender:Male
  • Location:Ohio
  • Local time:02:18 AM

Posted 08 September 2012 - 05:58 PM

  • Does the router power on. -----> Yes go to step 5. No go to step 2
  • Check the power supply
  • No out put---> replace the adapter and reset the router.
  • Voltage Less then required (12V 800ma to 2A) Replace the adapter, Reset the router
  • Reset the Router to factory defaults.
  • Check the all LAN and WAN connections for physical connectivity. If All ports show "connected" (green light on network adapter, port connection light on router) Go to step 9. If any fail go to step 7
  • Use another PC to test the interface of the router and the PC (you can plug the two computers together the status lights should turn on).
  • If the PC fails replace the NIC, Router fails the Internal Switch is likely damaged.
  • All connections good, Power cycle the entire network and check for connections

  • Turn off all Network devices including the Modem.\
  • Unplug all network cables.
  • Turn on the Modem Wait for the online light to steady
  • Plug in the Router and power it on.
  • Wait for the WAN/online light to steady
  • Plug in and power up all computers.
  • Check for connections

10. Still no connection ---> Re flash the router firmware using the method provided by the manufacture.
11. That is usually the last ditch effort.

To protect all devices use network lightning and surge protectors on power and Ethernet connections, Make sure home wiring is properly grounded.

Parts that can be damaged,

  • The internal Switch of the router,
  • The flash memory of the router,
  • the Processor of the Router,
  • The NIC of the PC
  • The power adapter for the router
I am sure there is something I may have missed but that's where I start.

Edited by Sneakycyber, 08 September 2012 - 06:00 PM.

Chad Mockensturm 

Systems and Network Engineer

Certified CompTia Network +, A +

#3 Platypus


  • Moderator
  • 14,194 posts
  • Gender:Male
  • Location:Australia
  • Local time:04:18 PM

Posted 08 September 2012 - 11:59 PM

One thing that's often not made clear about damage from lightning strike is that it is rarely a direct lightning strike to equipment or wiring that causes the damage. If it is, of course the damage can be enormous. Damage to small devices like routers and the line loop circuits of phones and modems can be attributed to induced currents caused by the magnetic field of remote strikes. A lightning strike conducts tens of thousands of amps of current, and long wires such as power and phone cables which are nearby, but not struck, can have large currents induced in them, like happens intentionally between the windings in a transformer. As this article comments:


"It has been well documented that direct lightning strikes are responsible for a small percentage of damage to electronic equipment. In excess of 90% of the damage occurs due to indirect effects."

Top 5 things that never get done:


#4 Platypus


  • Moderator
  • 14,194 posts
  • Gender:Male
  • Location:Australia
  • Local time:04:18 PM

Posted 09 September 2012 - 12:08 AM

There are some interesting videos here:


Top 5 things that never get done:


#5 Baltboy


    Bleepin' Flame Head

  • BC Advisor
  • 1,430 posts
  • Gender:Male
  • Location:Pennsylvania
  • Local time:01:18 AM

Posted 09 September 2012 - 12:41 PM

Electrical storms cause to conditions. Overcurrent when the strike adds voltage to the line. This usually causes the burned out parts you were refering to. The other side is undercurrent(brownout) where the current dips below accetable levels buts is still supplying power. This can be even worse than overcurrent because unless you are running everthing on a UPS you have no protection. Undercurrent will put a great deal of stress on electronics causing the components to fail internally in strange ways. Before every computer in my house, there is a few of them, went onto UPS systems I lost two to undercurrent events. The last one killed almost everything. Strangely the processor, memory, DVD drive, and hard drive survived. The video card had the fans fried but the card itself still works to this day. It even took out my mouse and keyboard. All electrical devices have a amperage, voltage, and hertz rating(unless it is DC powered like most electronics), that they need to hover around to work right. Varying anyone of them outside of the acceptable range can cause permanent failure.
Get your facts first, then you can distort them as you please.
Mark Twain

0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users