OT - Lighting Strike!! DOH

tadpole wrote on 5/5/2003, 12:10 AM
Ok, not sure if i really have a question here as i pretty sure what happened..
guess I am just looking for a confirmation before filing with insurance company.
(Plus give a WARNING to all those that like video editing during thunderstorms!)

My house?/Cable Tv line? got hit by lighting the other week (heard a loud crash and some snap-crackle-pop in the walls)

My system was configured/hooked up for previewing on TV monitor - as follows:
Computer <-> [firewire] <-> Video Camera <-> [RCA cables] <-> Video In RCA on VCR <-> [Coxial Out] <-> TV/preview monitor

**note: VCR's coxial input was hooked into Cable TV line

Now, I wasn't actually previewing at the time (was watching the TV, so camera was OFF - but VCR was ON and I was using it as channel tuner - computer was also ON. (All cables where connected as described above)

After the strike - TV went blue screen (power did not go out)
I am immeditaltey turned everything off.

After powering back up - I could no longer tune channels via the VCR.
The TV (preview monitor) however, still worked fine and i could change channels

TV in other room (which was off) could also NOT tune in any channels/signals when i tried.

My Conclusion, is that the lighting came in through the Cable TV line. Fryed the tuner? in my VCR and the tuner in my other TV. My preview montior/TV was spared the same fate because the VCR must have absorbed the charge?

Here's what really sucks (and thing i am not sure off as i don't have a schematic for my VCR wiring) - My video camera (which was connected to the RCA- in of the VCR) also seems to be fried. I can no longer get a signal from the RCA inputs on the camera to display on viewfinder (everything else still works fine on camera)

EVEN worse.. it appears the power spike proceed through my camera via firewire and into my firewire PCI card. Win Control panels displays the device is no longer working.

Is this possible? Could the power spike gone from cable tv wire, through VCR, out through RCA inputs, through camera, through firewire and ended up zapping out my firewire card??

Only thing i can think of since EVERYthing was working fine before the storm.
Doh!

Any electrical engineers in the house care to comment?
thanks!


Comments

Terry25 wrote on 5/5/2003, 12:46 AM
Well I can't answer your questions but I can share that I had my computer's power box blow (with a brilliant blue flash BTW) which killed my mobo and strangely my keyboard. However the actual CPU and PCI cards were fine. Strange thing electricity.
kameronj wrote on 5/5/2003, 1:29 AM
My power supply blew too - preety colors!!

Turns out the only thing that fried was the motherboard (go figure) and one of my hard drives. Luckily it was a drive I really wasn't using so I didn't loose any data (that I couldn't recover).

As for the originial question....can't help ya. I know how to turn stuff on - don't know how it works!! Isn't it magical or somethin???
Caruso wrote on 5/5/2003, 1:35 AM
I can't answer your question, either. But, I can share similar experience of how wierd and seemingly selective damage from lightning can be.

We once experienced random damage in an office that was the apparent result of a lighning strike on equipment in a remote office some thirty miles away. There was no storm at the office sustaining the damage. All that equipment was connected via a data line. We lost several display boards, but no damage to anything else in the office. Our tech people felt it very possible that the remote storm could have caused this damage.

I am still puzzled, becuase no apparent damage occured at the remote location.

My home VCR, a Sony Beta machine that I truly loved had its clock and tuner fried by lightning.

Fortunately, it still plays and records fine, just the clock and tuner went.

Caruso
Terry25 wrote on 5/5/2003, 3:29 AM
Maybe its like when a line of people join hands, give the first in line a shock and only the guy at the end feels it.
farss wrote on 5/5/2003, 4:03 AM
I've had quite a bit of experience with lightning strikes ove the years working with equipment that was tested under simulated lightning conditions. Most consumer electronics and much of the pro stuff pays no attention to this, it costs serious money, is dependent on adhering to strict installation requirements and is hardly sexy enough to make a sale. In maby cases cost of effective protection can be more then the value of what its protecting and if its not wired up right can make things worse.

HAving gotten that out of the way what you have had happen is not unusual. When you apply an above spec voltage to electronic bits the weakest one fails first. If your lucky that absorbs enough energy to protect the rest of the bits. If you unlucky it cannot absorb the energy so the next weakest bit goes, all this in the space of milliseconds. The extreme currents involved combined with the inductances can induce very high voltages in remote equipment also causing it to fail even though the source suffered no damage.

The biggest issue you may face is that sometimes the damage isn't enough to take things out immediately, youmay things not working quite right or failing months or years from now.

If you live in an area prone to lightning consider some protection gear. But the most important trick is to connect it to very solid earths. I know this is not common practice in the US (its mandatory in Australia). Its no use having these things, which are surge diverters, diveting all that current to anywhere other than ground. You can get into a situation where they divert the current to a dodgy earth which is connected to all your other gear and the whole lot goes. Stick a big metal stake in the ground. Run a really heavy gauge piece of wire up to the earth connections on the protection devices. For added security have them at every point every external cable enters your house. Even if the cable guy tells you his interfac box has surge diverters ask him just where is it going to divert to? Give him another fat wire from your earth stake to hook on.

If you don't think its worth all this trouble to save your gear, just think what could happen if you were one of the weak links in the chain. Imagine if you had been wearing headphones, you'd never be worrying about loosing audio sync again!


TheHappyFriar wrote on 5/5/2003, 6:56 AM
Lightning is horrible. I got kinda hit myself once. Wsa working on a metal haywagon and it struck about 10-15 feet away, then the wagon, then me! :( But, conisider yourself LUCKY! Everything could of blown, including the monitor you were working on, and it in your face!
I've never had lightning blow out any of my equipment (knock on wood). If you have lots of money in your equipment, consider getting a surge arrester (never heard of a surge diverter, will look into. maybe the same?). Those are susposed to STOP lightning surgers at the cost of themselves. I do know that here in NY (not NYC) if you have lightning rods some insurance companies won't cover you for lightning damage on what the rods were mounted on, but you don't really have to worry about lightning doing any damage (talked with a few farmers about that one).
Cheesehole wrote on 5/5/2003, 8:45 AM
>>>I know this is not common practice in the US (its mandatory in Australia).

Often the ground is wired to to a water pipe. Plus the ground wire would be connected to all my other equipment.... hmmm. Sounds like a fat wire and a stake would be a lot safer! Thanks for the advice.

Living in the lightning capital of the US, I wonder if I should subscribe to this service from my electric company that claims offer protection from lightning strikes... or do those surge protecters that claim to protect against lightning really work? Better get researching since it's almost lightning season!
musicvid10 wrote on 5/5/2003, 1:25 PM
When lightning hits a ground loop (like a catv coax shield) it takes the shortest path to ground, probably through the ground wire in the electrical system. The outside ground wire should have taken care of it, but a stake in dry soil isn't exactly a low resistance path. Anything on the loop could have taken a momentary hit.

I had one lightning strike that hit the neutral leg of my house wiring and took out two phones, the main hvac thermostat, the dishwasher power switch, and a power supply. Fortunately the rest of the computer/video stuff was OK. Very little you can do except prevention with good lightning arrestors on all incoming services outside the house.