Actually, now that we've switched away from floppy drives, CRT monitors and the older kinds of spinning hard drives (HDDs), magnets aren't a problem for computers anymore.
Most modern components have very good shielding to begin with, and you would need something ridiculously powerful, like an earth magnet, to do any damage to them.
Magnets have a bit of a bad reputation when it comes to computers. Many of us have heard that magnets can wipe our hard drives, wreak havoc on our computer monitors, or that magnets distort the flow of electrons through cables. Stories like that could make people nervous about using anything magnetic around their computers. But, let’s pause for a second and look at the facts. The concern about the dangers of mixing magnets and computer components came from the days of floppy drives. Stick a cheap magnet to a floppy drive and whatever information was stored would be gone. We’ve come a long ways from floppy drives however, so how do our electronics hold up against magnets today?
CRT monitors (those big tube monitors everyone used to use) use magnets to help project the image on the screen, so an external magnet would definitely cause some problems if the monitor wasn’t shielded. Placing a magnet next to one of those monitors made it look like a kaleidoscope. But LCD and LED monitors (the flat screen monitors we use today) function completely differently, so they are generally not affected by magnets. After all, your speakers use magnets to work and they don’t mess with your monitor, so the MOS is perfectly safe to use.
The worry here is that magnets can delete the information stored on your hard drive. Because of how hard drives work, magnets won’t delete anything from your hard drive. Your hard drive has a very powerful magnet inside that controls the read-write head movement. If the magnet inside the drive itself doesn’t delete information, any magnet that isn’t insanely powerful won’t wipe it either.
While a magnet isn’t going to wipe your hard drive, if you leave a powerful magnet directly on top of your hard drive there is a slight chance that it could cause damage to the hard drive itself while it’s functioning. The easy solution: don’t put a magnet directly on top of your hard drive during use. By doing that, you can be confident that your hard drive, and the information stored on it, is completely safe.
Flash memory is used in things like SD cards, thumb drives, and solid state hard drives. Because there is nothing magnetic about flash memory, it is completely immune to magnetic fields.
Cables can be affected by magnetic fields while in use if the cable isn’t shielded. Ribbon cables, for example, usually aren’t shielded, making it possible to cause interference. Even in these cases, the interference would be minimal, causing a slight change in the quality of the signal. However, most round cables are shielded against magnetic interference. Moreover, even in unshielded cables this interference happens only if a strong magnet is next to the cable while it’s being used. If the cable isn’t in use, there isn’t any danger of interference.
Unless you still use floppy drives, there really isn’t any danger in using magnets around your computers or electronics. Of course, if you are still using floppy drives, perhaps you have bigger issues to worry about than magnets.
- Jared Norman, "Fact or Fiction: Do magnets interfere with our electronics?"
