It had been a wonderfully sunny and warm Good Friday in West London but at about 5.30 the heavens opened. Right in the middle of the new Doctor Who (curses!), there was a huge ZAPPP and both my PC and TV went off (the TV being through a digital box). If I’d appreciated that the storm was so close I would have turned both off but it sneaked up on me.
The PC was protected only by the 13 amp fuse in the plug. It does seem to be still ‘alive’ – the power light comes on when plugged in – but nothing happens.
Before I start spending any money on it, could some computer-savvy Doper please advise me whether there’s any possibility of getting it fixed? If not, can I presume that I can recover the stuff saved onto it?
Unfortunately if it was working at the time, you cant assume anything survived. Some or even most components may have, but its also possible pretty much everything is fried, including your data.
It all depends on how much got damaged by the lightning. This could be a relatively simple fix, or the entire thing could be fried inside. There’s no way to tell unless you test each component. You can hope for the best, but be prepared for the possibility that everything inside the computer could be damaged beyond repair.
The power supply, motherboard, and CPU all have to work for the thing to fully turn on. The fact that it only partially turns on means you’ve got at least one problem with these components.
There is no guarantee that you’ll be able to recover anything off of the hard drive. There is nothing in your post that indicates one way or the other as to whether the drive survived the lightning strike. You don’t have enough of the computer working to test the drive.
Depending on how old the machine is, this may be your excuse to upgrade to a new computer. If you put the old drive in an external case and connect it to the new computer you may be able to recover your old data.
It could be as simple as the fuse and varister in the power supply are damaged. If you can’t check and replace these, a new power supply can be as cheap as $35 here. Maybe you could borrow one as a test. They are simple to install. It it turns out to be more than that, move on.
Almost impossible to guess what the damage might be. Lightning knows no boundaries. The insides could be half vaporised (less likely, I would remove the disk drive, take it to a reliable recovery place and explain what happened. Be very careful not to simply try to boot a machine off your disk. Until it has been proven to be OK, and the file system within intact, assume it is damaged and treat it as such. A potentially damaged disk should never be mounted for write access, always mount read only and get the data off to somewhere safe. Only when you have done that think about worrying about the computer. Even if the disk appears to come back OK, still replace it. Disks are too cheap to even consider using a disk that has weathered a strike. A damaged disk controller that slowly fails is about the worst thing you can imagine.
The only thing you can really do is buy or borrow a power supply and see if it powers up. I think its rare for only the ps to be damaged, but you might luck out.
i’ll agree with you can’t know. how much high voltage got into it and how far determines the damage. at minimum might be the power supply, external monitors and then the video card are also likely to be damaged. the hard drive might still be readable and you should copy important data off it as soon as you can.
not only is turning things off good when strong storms are near but also unplugging them is a good thing; power cord as well as antenna, tv cable, phone cable.
If I can piggyback a related question, is this something that is preventable by plugging all computer components into a surge protector? I can think of very few events that would be more nightmarish than this.
Surge protectors don’t do much frankly. They’ve got components that are “used up” after they absorb a certain amount of electric surges (I’m oversimplifying…) A new, high-quality surge protector might shield your electronics from a year’s worth of minor spikes, or just a single nearby lightning strike. After a while though it doesn’t provide any protection and it’s just another ordinary power strip.
Most people get away with it because they’ve got a good electricity grid without lots of power spikes. And modern power supplies can handle modest spikes without much trouble. Electronics are quickly knocked off by dramatic things like lightning strikes, or antiquated rural service where the neighbors use their cheap arc-welder every day.
That’s a pretty expensive way to test a power supply. If you know someone who is handy with electronics, you can jumper a couple of pins on the power supply connector to force it to start up, then measure the voltages with a meter.
If it were completely dead I’d be tempted to open up the power supply and look for a fuse, and then maybe replace the power supply if it were more than that. Since it’s at least partially working, the chances of the motherboard being damaged are a bit too great for me to want to try buying a new power supply.
As was said, though, if you can borrow one from a friend you could find out easily if it’s just the power supply or not.
Surge protectors do help quite often. At once place where I worked, we had lighting hit the building and we lost every piece of computer equipment that wasn’t protected by a surge protector, and nothing that was protected. (Note - YMMV)
There isn’t anything that you can buy that can protect you from a direct lightning strike, though. Even the best surge protectors have their limits.
The two things to look at in surge protectors are the clamping voltage and the joule rating. The lower the clamping voltage the better, and the more joules the better.
To keep it in perspective, a good surge protector might handle a couple thousand joules. A lightning bolt has a few billion joules of energy in it. That’s why nothing will even come close to saving you from a direct strike. Lightning will travel a good distance down power lines, though, so those few thousand joules of protection can easily make the difference from an indirect spike or surge.
A UPS will give you even more isolation from the power line and will also give you a battery backup to allow your system to keep running for a bit, but a UPS costs quite a bit more than a surge protector.
First, it should be obvious that no fuse protects hardware. A fuse is for human safety. To disconnect power after hardware damage has been done. So that a house fire does not kill the homeowner.
If damage was from a surge, then it found earth ground destructively via that computer. Your failure is directly traceable to no protector at the only located where it can be effective. When lightning entered the house with a short as possible (ie ‘less than 3 meter’) connection to single point earth ground.
Now, a computers power supply system is more than just a PSU. Normal is for lights to glow and disks to spin. And the power ‘system’ is still defective.
Use a multimeter (ie £8 from Malpin) to measure voltages on six wires. Report those numbers. And have a completely (and useful) answer in the next post.
Or just start replacing good parts until something works. Those are your only two options.
Of course, learn from the failure. Either energy dissipates harmlessly outside the building. Or it finds earth destructively via appliances. Some are so foolish as to recommend protectors that do not even claim protection. Will hundreds of joules inside a silly little power strip absorb hundreds of thousands of joules? Of course not. Ineffective protection. Will a 2 cm part stop what 3 kilometers of sky could not? Of course not. Again, ineffective. That is what a £25 protector strip does. A fuse also does not claim any protection. Learn by first identifying what has failed - not before replacing anything.
As others have said, your first priority should be your data. In the US you can get an external case (IDE or SATA) for about $30. Mount the drive in the case and connect it to a working computer to see if it is readable. If it is, I would get an external drive and copy the data to the external drive.
Once you’ve done that, I would return the drive to the computer and start mucking around.
I’ve had systems that wouldn’t boot that were perfectly functional and only required that the bios be reset. That’s pretty easy to do and anyone here can probably tell you how.
If that doesn’t work, I would visually inspect the board for anything that is obviously amiss. Are there scorch marks, blown capacitors (you’ll know it when you see it), etc. If not, then the first suspect is the powersupply. I always have spare parts around so I see nothing wrong with trying another PSU. If that’s not an option and you don’t feel qualified to test it yourself (i build computers and never use a multimeter either), then just bring the whole thing to a shop you trust and ask them to check it out.
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Doesn’t matter. What matters is the lightning strike grounded through your home, specifically your PC and TV.
My parents home has never been struck by lightning. Yet twice lightning has struck power lines (one more than a mile away) and the strike was ultimately grounded in my parents home (despite all the other homes and ground links in between). Still, the grounding was weird. The operating TV and other assorted/connected electronics were left untouched, but the toaster burned out. In the another case, a ceiling light bulb exploded but everything else was just fine.
You could have taken all the precautions in the world before the storm. It still might have made no difference in the outcome.
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IDK, but I would guess that a UPS would be effective in preventing damage since it takes AC, converts to DC to charge the battery and then takes power from the battery to feed the computer. At least in theory that’s how it’s supposed to work so you always get perfect sine wave power.
In the case of a lightning strike, it should ground out through the UPS and leave the computer untouched.
A real lightning strike will laugh in the face of a UPS, and destroy it on the way past just of the fun of it. Lightning doesn’t obey the usual rules of current flow, and will cheerfully bypass your puny ground wire (or vaporise it, depending upon its mood) and then go on to fuse into solid lumps of metal other components. Just for the sheer contrariness of it, it will leave a random object unscathed.
Surges due to a nearby strike can be anything from an inconvenient power drop (as the supply transformers saturate) through to as many tens of thousands of volts as you like frying everything electronic in your house.
Maybe, but I don’t think it serves any purpose to assume the worst. It’s the difference between walking into a riot naked and wearing protective gear. Yeah, you might still get creamed by a passing asteroid, but your odds are a lot better.
even if you don’t have a direct or partial lightning strike, the lightning can induce high voltage currents into any metal (power grid, phone grid, cable grid, metal fences, rain gutters, antennas) within a couple of miles. this has a greater effect on the grid in rural areas where there are fewer paths to ground (you can see arcs coming out of phone jacks from not real close lightning).
Air is nonconductive relative to many other things. Lightning has just traveled miles through nonconductive air. Appliances and household devices are designed to be used with hundreds of volts (maybe a few thousand in a high voltage application), a few inches of air is needed for isolation. A high voltage surge caused by lightning can jump around inside of most devices finding paths to ground and causing damage on the way.
ham radio people who have power grid connected, antenna connected, costly devices would disconnect whenever you could hear thunder. a popular ham magazine would have this advice as a white space filler.
I did not know this. Is there any way to test how good a surge protector is? I have really spiky power. Should I just replace all my surge protectors annually?