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Recover HD Using a Magnet

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Re: Recover HD Using a Magnet

#21

Post by commandlinefan »

pontifier wrote: post #16
mirimir wrote: post #5

Earlier quoted context omitted.

It's changing magnetic fields that wipe HDDs. Such as powerful electromagnets. In a clean (enough) room, they could have opened the drive, and just poked the actuator arm. Decades ago, I had a HDD that wouldn't spin up unless I nudged the platter with a pencil erasor. Very near the center, of course. There was a hole in the case, in just the right place, with Al tape over it.

Doesn't even have to be a very clean room... I played around with an old 1 gig drive years ago. My friends and I opened up the case so we could watch the drive doing it's thing. We did a fresh os install and watched as it formatted the disk and copied files. The head was remarkably strong, and would move so fast it looked like it was in 2 places at once while copying files. It was fun to stick a screwdriver between t…

If you videoed any of that, I'd love to watch it on youtube (or somewhere).

Re: Recover HD Using a Magnet

#22

Post by pmiller2 »

sdfjkl wrote: post #20

I've fixed this problem a few times (on different drives) by giving the drive a not so gentle thwack with a hammer. The trick is to hit it on the long side, which tends to dislodge the stuck heads/arm. If you hit it on the top or bottom, you're likely to break something, and hits on the short side aren't likely to achieve anything at all.

I've used this method after the fridge/freezer method failed. It seems less likely to cause data loss than using a magnet to move the head as in the article.

Re: Recover HD Using a Magnet

#23

Post by ebg13 »

EvanAnderson wrote: post #7
cecja wrote: post #6

Earlier quoted context omitted.

the whole magnet and hard drives thing is a really old hoax. with normal household magnets or even strong neodym magnets nothing will happen to your data but if you have a really strong industrial electro magnet at hand you can wipe a drive with it... here is an old national geographics video on the topic https://www.youtube.com/watch?v=U8LWTe5CqQg

Here's my anecdote: In 2006, while sitting at my desk playing a video on the Travelstar 40GB PATA drive in my Thinkpad T22, I held a single neodymium magnet (harvested from an old hard disk drive) about 6 inches from the left side of the unit (where the ~disk was located). The video froze, Windows XP blue-screened, and the hard disk drive started emitting a ~10Khz whine. I jerked my hand away from the PC immediately…

> the hard disk drive started emitting a ~10Khz whine

This sounds like the head crashed and physically scraped the platter.

Re: Recover HD Using a Magnet

#24

Post by noonespecial »

EvanAnderson wrote: post #9
egdod wrote: post #8

Earlier quoted context omitted.

Sounds like a coincidence.

It does sound that way but, boy, it was eerily timed if it was.

I'd bet on related, but not what you thought. If I had to guess, I'd put my money on the magnet pulling some tiny metal bits into the control board and shorting it.

But one thing is for sure. OnTrack are dicks. Can confirm.

Re: Recover HD Using a Magnet

#25

Post by FabHK »

mlyle wrote: post #10
EvanAnderson wrote: post #9

Earlier quoted context omitted.

It does sound that way but, boy, it was eerily timed if it was.

Magnetic field falls off with inverse cube of distance once you're past the approximate size of the magnet. Not to mention that the drive itself is in a ferrous enclosure that provides a lot of shielding... the magnetic field you applied at 6 inches is approximately nothing.

Isn't it inverse square?

Re: Recover HD Using a Magnet

#26

Post by jacquesm »

Clever! I'm stuck on a problem right now as well, I'm trying to boot an old server (Supermicro, dual CPU) to verify something and for the life of me I can't figure out what is wrong with it. It doesn't do anything when you power it up, even the power led on the board doesn't light up. Forcing the powersupply to 'on' does light up the LED but the system still won't boot. Already put a fresh 3V cell in it, stripped it down to the bare minimum, all jumpers in default positions, no go. And it worked perfectly fine the last time it was shut down. Highly frustrating these gremlins.

Re: Recover HD Using a Magnet

#27

Post by gist »

pontifier wrote: post #16
mirimir wrote: post #5

Earlier quoted context omitted.

It's changing magnetic fields that wipe HDDs. Such as powerful electromagnets. In a clean (enough) room, they could have opened the drive, and just poked the actuator arm. Decades ago, I had a HDD that wouldn't spin up unless I nudged the platter with a pencil erasor. Very near the center, of course. There was a hole in the case, in just the right place, with Al tape over it.

Doesn't even have to be a very clean room... I played around with an old 1 gig drive years ago. My friends and I opened up the case so we could watch the drive doing it's thing. We did a fresh os install and watched as it formatted the disk and copied files. The head was remarkably strong, and would move so fast it looked like it was in 2 places at once while copying files. It was fun to stick a screwdriver between t…

That's pretty cool. I had a few old drives and on purpose took them apart. So far I was not able to duplicate what you were able to do (this was last month). I had an idea that it might work in some way. Glad that you can confirm it did at least when you tried.

Re: Recover HD Using a Magnet

#28

Post by gist »

cecja wrote: post #6
azinman2 wrote: post #2

How did the data not get destroyed by the magnet?

the whole magnet and hard drives thing is a really old hoax. with normal household magnets or even strong neodym magnets nothing will happen to your data but if you have a really strong industrial electro magnet at hand you can wipe a drive with it... here is an old national geographics video on the topic https://www.youtube.com/watch?v=U8LWTe5CqQg

Interesting one of the first 'tales' I read about was some person in (I think) Sweden who took his drives home in his car with heated seats. And when they needed to use them they wouldn't work. The point was 'you have to test backups'. Now that I am thinking of it possible this was even with tapes not hard drives.

By the way with that video I am also thinking maybe it wasn't the magnet that scrambled the drive but some other force that was applied as a result of the effect of the magnet on chips or the laptop. [1]

[1] I don't think that was what happened but the test does not isolate the drive from any other possible impact is my point.

Re: Recover HD Using a Magnet

#30

Post by gist »

ebg13 wrote: post #4
azinman2 wrote: post #2

How did the data not get destroyed by the magnet?

There are actually very powerful permanent magnets inside of every spinning hard drive already, so clearly there's more to destroying data than just having a magnet nearby. https://www.kjmagnetics.com/blog.asp?p=hard-drive-destructio... has a writeup about trying and failing to wipe a drive with extremely powerful magnets.

You know what is sad about a small business (kjmagnetics.com) that you linked to? They are exactly what will be killed off by Amazon. The small and knowledgeable specialty store very similar as I am sure many of us remembered happened to 'Stereo Stores' once the big boxes stores came along (or hardware stores). Nothing new about this of course just that with Amazon it's greatly accelerated.
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