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can a magnet harm a laptop screen

Discussion in 'Laptops' started by don, Apr 3, 2010.

  1. don

    don Guest

    I was wondering if a magnet could possibly harm a laptop screen.
    Does a magnet destroy the pixals or anything.
    don, Apr 3, 2010
    #1
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  2. don

    BillW50 Guest

    In news:hp6o0b$psp$,
    don typed on Sat, 3 Apr 2010 02:43:50 -0500:
    > I was wondering if a magnet could possibly harm a laptop screen.
    > Does a magnet destroy the pixals or anything.


    Nope, flat panel screens are unaffected by magnetic fields. Unlike CRT
    color monitors which are. In fact, most modern laptops mount a magnetic
    right next to the screen to operate the lid switch.

    --
    Bill
    Gateway MX6124 ('06 era) 1 of 3 - Windows XP SP2
    BillW50, Apr 3, 2010
    #2
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  3. No, not within reason (I will assume that you don't stick an LCD screen
    into an MRI machine).


    don wrote:
    > I was wondering if a magnet could possibly harm a laptop screen.
    > Does a magnet destroy the pixals or anything.
    >
    >
    >
    Barry Watzman, Apr 3, 2010
    #3
  4. don

    Adrian C Guest

    On 03/04/2010 08:43, don wrote:
    > I was wondering if a magnet could possibly harm a laptop screen.
    > Does a magnet destroy the pixals or anything.


    No.

    Try something else.

    --
    Adrian C
    Adrian C, Apr 4, 2010
    #4
  5. More myth than reality. While hard (and floppy) drives are magnetic, it
    is just about IMPOSSIBLE, with any magnetic source that normal people
    have access to, to erase a hard drive or floppy from any significant
    distance. The read/write head is extremely close to the platters
    (microns, for a hard drive, and touching for a floppy). Strenght
    decreases by the square of the distance. By the time time you are even
    just 1/4 to 1/2 inch away, erasing the disk is almost impossible. By
    the time you are 2 inches away, "almost impossible" becomes "essentially
    impossible", unless you have access to something like an MRI machine.


    davy wrote:
    > Keep it away from hard drives...!
    >
    > davy
    >
    >
    Barry Watzman, Apr 4, 2010
    #5
  6. don

    BillW50 Guest

    In news:hp9vkb$m6d$-september.org,
    Barry Watzman typed on Sun, 04 Apr 2010 08:10:47 -0400:
    > More myth than reality. While hard (and floppy) drives are magnetic,
    > it is just about IMPOSSIBLE, with any magnetic source that normal
    > people have access to, to erase a hard drive or floppy from any
    > significant distance. The read/write head is extremely close to the
    > platters (microns, for a hard drive, and touching for a floppy).
    > Strenght decreases by the square of the distance. By the time time
    > you are even just 1/4 to 1/2 inch away, erasing the disk is almost
    > impossible. By the time you are 2 inches away, "almost impossible"
    > becomes "essentially impossible", unless you have access to something
    > like an MRI machine.


    Others and I have done a lot of research into this area. And there are
    lots of myths and legends here. First all, it is a myth that a weak
    magnetic field will corrupt magnetic data in time. It just doesn't
    happen. While it is true that magnetic data doesn't store forever, but
    it isn't do to other weaker magnetic fields. Although the problem of
    print through, is still a bit of a mystery to me. Which happens with
    very thin magnetic tapes.

    Thus to write or destroy magnetic data, you need a very strong and very
    close magnetic field to do so. And there is a trip point. As a field
    just a tad too weak won't do anything. And one just barely strong enough
    will. The drive heads doesn't produce a strong enough field to say pick
    up nails or anything. But it is highly focused to a very small point.
    Thus why it works.

    And it is true magnetic fields you are likely to run into during normal
    day to day life isn't strong enough to do any harm. I also know that
    refrigerator magnets are not strong enough to harm anything. I am not
    sure if a 5 lbs magnetic is strong enough to do anything either.

    Now there is one device that some might have around (more so in years
    past) that could wipe out a floppy disk. Not sure about a hard drive.
    And that is a color CRT (TV and/or monitor). As there is a large coil
    around the CRT known as a degaussing coil. And they are usually designed
    to kick in briefly whenever you power up the device. And some of these
    coils in some of those devices are very close to the top. And some rare
    color monitors for example have been known to wipe out any floppy disk
    sitting on top when you power them up. Fortunately most color monitors
    won't no matter how much you try.

    There are manual degaussing coils too. I have one made for degaussing
    tape deck heads. And I could never erase a floppy with it. And it barely
    works for degaussing CRTs manually. So the one I have isn't quite strong
    enough to harm any magnetic data either.

    --
    Bill
    Gateway MX6124 ('06 era) 1 of 3 - Windows XP SP2
    BillW50, Apr 4, 2010
    #6
  7. A normal degaussing coil won't erase a disk, and the ones inside the set
    are particularly weak. People who service color CRT devices sometimes
    have much stronger coils that MIGHT be able to erase a floppy disk.

    One thing that some people have that could erase a floppy (but not a
    hard drive, generally) is a bulk tape eraser made for videotape (e.g.
    VHS cassettes, or, if anyone has one, 1" or 2" broadcast open reel video
    tape). These are rare, however, and you have to get it right up against
    the disk (which is why even those probably won't work on a hard drive).

    As someone pointed out, some of the strongest magnets you can easily get
    are magnets removed from the voice coil mechanisms (the head positioner)
    of .... HARD DRIVES. Those are seriously strong magnets, they are
    mounted INSIDE the drive itself only about 1/2" from the platters ....
    and they do not erase the platters, obviously.

    BillW50 wrote:
    > In news:hp9vkb$m6d$-september.org,
    > Barry Watzman typed on Sun, 04 Apr 2010 08:10:47 -0400:
    >> More myth than reality. While hard (and floppy) drives are magnetic,
    >> it is just about IMPOSSIBLE, with any magnetic source that normal
    >> people have access to, to erase a hard drive or floppy from any
    >> significant distance. The read/write head is extremely close to the
    >> platters (microns, for a hard drive, and touching for a floppy).
    >> Strenght decreases by the square of the distance. By the time time
    >> you are even just 1/4 to 1/2 inch away, erasing the disk is almost
    >> impossible. By the time you are 2 inches away, "almost impossible"
    >> becomes "essentially impossible", unless you have access to something
    >> like an MRI machine.

    >
    > Others and I have done a lot of research into this area. And there are
    > lots of myths and legends here. First all, it is a myth that a weak
    > magnetic field will corrupt magnetic data in time. It just doesn't
    > happen. While it is true that magnetic data doesn't store forever, but
    > it isn't do to other weaker magnetic fields. Although the problem of
    > print through, is still a bit of a mystery to me. Which happens with
    > very thin magnetic tapes.
    >
    > Thus to write or destroy magnetic data, you need a very strong and very
    > close magnetic field to do so. And there is a trip point. As a field
    > just a tad too weak won't do anything. And one just barely strong enough
    > will. The drive heads doesn't produce a strong enough field to say pick
    > up nails or anything. But it is highly focused to a very small point.
    > Thus why it works.
    >
    > And it is true magnetic fields you are likely to run into during normal
    > day to day life isn't strong enough to do any harm. I also know that
    > refrigerator magnets are not strong enough to harm anything. I am not
    > sure if a 5 lbs magnetic is strong enough to do anything either.
    >
    > Now there is one device that some might have around (more so in years
    > past) that could wipe out a floppy disk. Not sure about a hard drive.
    > And that is a color CRT (TV and/or monitor). As there is a large coil
    > around the CRT known as a degaussing coil. And they are usually designed
    > to kick in briefly whenever you power up the device. And some of these
    > coils in some of those devices are very close to the top. And some rare
    > color monitors for example have been known to wipe out any floppy disk
    > sitting on top when you power them up. Fortunately most color monitors
    > won't no matter how much you try.
    >
    > There are manual degaussing coils too. I have one made for degaussing
    > tape deck heads. And I could never erase a floppy with it. And it barely
    > works for degaussing CRTs manually. So the one I have isn't quite strong
    > enough to harm any magnetic data either.
    >
    Barry Watzman, Apr 4, 2010
    #7
  8. don

    BillW50 Guest

    In news:hpaiu5$kc0$-september.org,
    Barry Watzman typed on Sun, 04 Apr 2010 13:40:17 -0400:
    > A normal degaussing coil won't erase a disk, and the ones inside the
    > set are particularly weak. People who service color CRT devices
    > sometimes have much stronger coils that MIGHT be able to erase a
    > floppy disk.


    I would normally agree and I won't think that a degaussing coil found in
    a color monitor could erase a disk. But one tech showed me otherwise. As
    he had a monitor that would have about 1 in 5 chance to erase a floppy
    that was placed on top of the monitor. Since these coils are generally
    controlled by a simple PTC thermistor, there isn't much to go wrong. So
    either by design or malfunction, this one could erase a floppy. So if
    there was one in the world, surely there must be at least a handful of
    others out there that could do the same.

    > One thing that some people have that could erase a floppy (but not a
    > hard drive, generally) is a bulk tape eraser made for videotape (e.g.
    > VHS cassettes, or, if anyone has one, 1" or 2" broadcast open reel
    > video tape). These are rare, however, and you have to get it right
    > up against the disk (which is why even those probably won't work on a
    > hard drive).


    I never played with those and some have reported those bulk erasers
    doesn't do a very good job of erasing either. As I hear much of the
    information is still there anyway.

    > As someone pointed out, some of the strongest magnets you can easily
    > get are magnets removed from the voice coil mechanisms (the head
    > positioner) of .... HARD DRIVES. Those are seriously strong magnets,
    > they are mounted INSIDE the drive itself only about 1/2" from the
    > platters .... and they do not erase the platters, obviously.


    They could be strong magnets, I don't know. As I never tested one.

    --
    Bill
    Gateway MX6124 ('06 era) 1 of 3 - Windows XP SP2
    BillW50, Apr 4, 2010
    #8
  9. don

    ~misfit~ Guest

    Somewhere on teh intarwebs don wrote:
    > I was wondering if a magnet could possibly harm a laptop screen.


    It depends on how hard it's thrown.

    > Does a magnet destroy the pixals or anything.


    See above.
    --
    Shaun.

    Ticking away the moments that make up a dull day...
    ~misfit~, Apr 5, 2010
    #9
  10. don

    Adrian C Guest

    On 07/04/2010 13:22, RnR wrote:
    > On Sun, 4 Apr 2010 07:44:09 -0400, "Ralph Mowery"
    > <> wrote:
    >
    >>
    >> "davy"<> wrote in message
    >> news:...
    >>>
    >>> Keep it away from hard drives...!
    >>>

    >>
    >> Have you ever taken a hard drive apart and looked at the magnet in it ?
    >>

    >
    > As I recall magnets (plural)<grin>.


    Do you know, if you get enough hard drive magnets and attach them to the
    front of your car's front fender, you can save a good 10-15% on your
    fuel consumption on the freeway, simply by driving closer to the vehicle
    in front?

    [disclaimer: I might be fibbing. Do not try if you own a Toyota... ]

    --
    Adrian C
    Adrian C, Apr 7, 2010
    #10
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