Lightning strike damage  - Page 1
Forum section: electronics / repair

author: Buildingthings
author_rank: Contributor
timestamp: October 16, 2022, 03:17:52 pm
content: Maybe a weird topic of interest.I am a relative beginner in electronics, and have stacks of lightning damaged marine electronics under my bench. Some have gone totally blank screen, but the majority power up but with errors effecting inputs on the CAN bus, voltage sense errors, some keypad functions not working, flashing icons on displays, etc. The boats involved did not take the dreaded direct hit, but rather the lightning just zapped a lot of very expensive gear. Very random.My question is- after lengthy troubleshooting and repairs, would there be significant risk of shortened lifespan of the components still working? The gear is everything from 100 amp DC motor drives to very sensitive navigation systems.Thanks for any opinions from the much more experienced engineers out there.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 16, 2022, 04:03:23 pm
content: Probably not. But the tricky part is finding all affected components. Symptoms might include increased leakage current, degraded noise figure, more sensitivity to voltage or temperature, etc.Maybe easier at least on the nav stuff, as things on wires/connectors are most likely culprits. But depends on design, and poorly designed equipment can always fail worse (e.g. surge carried into internal supplies, with insufficient protection, most everything goes off like popcorn). Power supplies, converters, drives, etc. likely have multiple failures in key components (switches, drivers, controllers, aux supplies?).Tim

author: JustMeHere
author_rank: Frequent Contributor
timestamp: October 16, 2022, 06:38:28 pm
content: Your best bet is to file insurance and replace everything. Assume everything is damaged.

author: coppercone2
author_rank: Super Contributor
timestamp: October 16, 2022, 07:32:47 pm
content: your gonna end up adrift, that is too much damage for something too important to repair DIY. At least replace the critical thingsIf it damaged a 100amp inverter, which is probobly built like a beast, that stuff is probobly really fucked up. The additional stresses of martime operation + damage make it really dodgy. Like imagine the parts had a little bit of undetectable corrosion damage before the lightning hit, and the propagation path was non standard for lightning, the isolation specification might not be up to par after a few years at sea. Little bits of internal corrosion here and there might change some discharge paths. I would say avionics might be safer to repair, since you are only dealing with additional vibration there (unless its like a plane that lives near a swamp in cambodia).And if the computer is having problems that signifies some strong damage. If it was like a busted radio receiver front end thats one thing (especially since you have multiple radios), but once computers are going haywire that means shit really got deep into the system IMO, everything might be effected. Tracking down some damaged ram intermittently doing weird stuff involved with a DSP??screwed up navigation sonar processors??you have to run memory integrity tests, replace all protection elements, check stuff for leakage, do a full visual inspection for damaged components, probobly replace all the switching transistors, re-check the EMI spec, etc. Its too much IMO. Like imagine desoldering all the components off a circuit so you can check for internal leakage inside of a barren PCB (arcing residue between two internal via or something). There could easily be a ton of internal damage that makes it more likely for the system to fail with a much more modest strike that it would have shrugged off prior, if it has certain kinds of damage that are just not practical to find.

author: coppercone2
author_rank: Super Contributor
timestamp: October 16, 2022, 07:50:29 pm
content: for example I had a PC with lightning damage that effected a whole bunch of stuff in the house, a while later when I was looking at bios the settings names were screwed up (eeprom or whatever), and the PC started crashing and stuff. I did use it for years after with a NIC, but configuring the bios was hard lol... but thats not something you wanna deal with on a damn boat

author: manicdoc
author_rank: Unknown
timestamp: October 16, 2022, 08:25:29 pm
content: had a tree lightning strike at home after a lot of rain. The ground potential shot up and caused an induced current on the mains line to the front gate. Literally 'blew' the fuse into atoms and fried the gate controller, transformer and two PIR sensors. then because the gate was under automation control, a spike was induced on the lines back to the Comfort control board, fried that, and then fried a network switch... Cost $600 to fix and I put in additional MOV's, spark gap, etc to give it multiple paths to ground. Hopefully, if there is a next time, less will go pop.As others have said, better to replace if the protection circuitry has failed - the damage could be all over the place.

author: Buildingthings
author_rank: Contributor
timestamp: October 17, 2022, 12:27:07 am
content: Quote from: coppercone2 on October 16, 2022, 07:32:47 pmThank you. I think that really seals the deal, truly a heroic repair process as described. Your point about potential increased vulnerability to a future strike made me think about other things even more likely to happen, like back EMF spikes. The same logic would apply there I believe. Some big pump cycling on and off that the systems tolerated before might now damage things.

author: Buildingthings
author_rank: Contributor
timestamp: October 17, 2022, 12:39:22 am
content: After reading all the comments I think the only reasonable thing to do with lightning damaged complex items it all is to recycle what components that can be easily tested, perhaps displays, keypads, ports, and the housings of course.The items with simple circuitry might be worth the effort, or good learning projects when time is available.

author: coppercone2
author_rank: Super Contributor
timestamp: October 17, 2022, 01:02:17 am
content: well those known interference sources you can probobly test out by using logic, but I would be more worried about robustness against further lightning strikes. Like it sounds like if you were just a little further off, you would have been fine, since that stuff was brand new, but now what if the strike survival distance is like only 60% of what it used to be? You get alot more risk. That is going to be incredibly hard to test.I know people do pretty hardcore avionics repairs, but it seems that planes are generally harder to damage to the same amount as a boat, and I think the atmosphere of the sea area makes for a hell of a wild card when it comes to circuit robustness.I bet those PCB are totally covered in like varnish tooI would make a list, not referenced to cost, basically what things are allowed to fail randomly that lead to a safety problem. If its a for-fun radio, ok... give it a shot repairing it, but if its going to lead to anything more then a inconvenience, its pretty hazardous to risk leaving around after lightning damage. I am thinking that if some keypad breaks on you, and you can't call for help, its gonna screw you.

author: coppercone2
author_rank: Super Contributor
timestamp: October 17, 2022, 01:10:48 am
content: and for the motors and shit, you probobly should do a megger test also, if you want to keep anything big/bulky around. Never know if the insulation got damaged.After some kind of power incident in my home that took out 5 power strips and a clock, a few other things failed a while later. The portable AC started tripping the GFIC, and when I tested it, the insulation to chassis was only 50Kohms, and it should have been like 50 megaohms. Bad enough to pick it up with a regular meter, I bet the winding might have gotten a little cooked and eventually caused enough leakage for a GFIC trip.For the cable harness ETC, you wanna do a full inspection and impedance test to look for burned out pins and stuff like that.. with some connectors, its going to be very hard.I think also looking for foil capacitors that have a lower then expected capacitance are a sign of over voltage, since the foil will arc over inside and the self healing will be detectable as a capacitance drop (less metalization), even if there is no leakage.Check the capacitors near a motor, compare to tolerance, and its kind of like 'burn marks' used for a cursory investigation if its lower for some reason.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 17, 2022, 01:29:46 am
content: Quote from: manicdoc on October 16, 2022, 08:25:29 pmSo I've heard from those working on power distribution equipment -- ground lift (common mode surge) is an exceptionally severe standard. I don't know that it really...has to be, or anything, but probably being common-mode (or worse, normal mode, I forget?) makes it, either that much harder to understand, or to protect against. Your example might even be a more mild case, which goes to show how nasty these events can get...Tim

author: SmallCog
author_rank: Frequent Contributor
timestamp: October 17, 2022, 02:12:31 am
content: If you just want to fix them as a step to learning fault finding etc then there's no harm in it.If you want them fixed to use as bench devices then there's no real harm either. By bench devices I mean for use in testing other items (eg if you're repairing an autopilot and it's only happy when the "xyz" is hooked up to it, fix up an "xyz" and use it for testing autopilots on the bench.Also... If you have a small boat that wouldn't normally have super fancy commercial grade equipment, but you can get your hands on some repaired commercial equipment, then why not add it? EG a super fancy chart plotter that would normally be outside your reach. You might only go fishing within 200m of the shore or in a river but want it because it's "cool"I wouldn't however trust it for use in a commercial vessel, or non commercial vessel where it's safety critical ever again

author: james_s
author_rank: Super Contributor
timestamp: October 17, 2022, 02:20:49 am
content: Quote from: Buildingthings on October 17, 2022, 12:39:22 amI wouldn't be that quick to condemn the stuff. Lightning can be very unpredictable, it can do extensive damage in one thing and leave another virtually unscathed. For me it would depend on what the gear is used for. If it is a life critical system where you are screwed if it fails then it's probably wise to replace it. If it's just a nice to have instrument or a toy then by all means take a crack at fixing it. It's worth considering that there is a huge amount of gear out there that has survived nearby lightning strikes without obvious damage that could be just as compromised in some non-obvious way as stuff that failed and was repaired.I don't see much lightning damage where I am, but I did repair the electronic control board in a dishwasher years ago that had been damaged by lightning. The main fuse had literally exploded, the surge protection MOV split open and the thermal fuse embedded in the transformer primary was open but I fixed it, gave it to my grandmother and it was still working a decade later when she died. Most people would have thrown it away but it was a nice appliance that I was able to fix with bits I had on hand.