I remember when I was growing up (decades ago), my dad instilled in me to never put a magnet up to a computer or TV because they would cause irreparable damage to the screen. While I’m sure that SOMEWHERE out in the world there’s a magnet strong enough to cause damage if given enough time or whatever, but in terms of what I can buy from a store, would it be safe to keep my cell phone and a magnet (say, one of those ‘clicking’ fidget toys with half a dozen or so small magnets) in the same pocket, or am I just asking for trouble?
Edit: Thank you everyone for all your answers! I now know far more than I expected to from this silly question 😁
If you want to see that really strong magnet: https://youtu.be/OC7sNfNuTNU at 1:34:55
Magnets can damage CRT televisions and mechanical hard drives (not solidstate ones I don’t think). I’m not necessarily going to test it by rubbing magnets all over, but for the most part those two things have fallen out of use. Tech is a lot less… Moving now. I guess is a good way of putting it. With hard drives specifically it would cause the arm inside to move and scratch the disk.
With hard drives specifically it would cause the arm inside to move and scratch the disk.
Really? I thought magnets placed near hard drives would just magnitize the platters in such a way that the data would be destroyed. In that case it would still work if reformatted I think.
UNIX Neckbeard here:
Magnets use to affect the magnetic hard drives (spinning platter, HDD) that were inside computers. This was especially bad because it would erase data permanently. It was the main concern about magnet+computer that everyone was worried about. CRT monitors were affected by magnets, but the inbuilt degauss or a handheld degaussing coil would usually correct the issue.
If your device has solid state storage (basically everything nowadays) that concern went away. Any other issues (like affecting the compass or accelerometer in a phone) are only temporary.
I have never heard of a magnetic field damaging an LCD and a quick google search says that’s a myth. Pressing on an LCD will damage it, so maybe a really strong magnet that was placed on an LCD that had ferrous metal behind it physically broke some LCDs and the myth was born, when really it was just pressure that broke the LCD.
I’m always wary of stacking hard drives together because they have magnets in them, but at the same time, they’re designed to be stacked. I guess I worry more about loose external drives.
So I guess you just need a really strong magnet to cook the device by induced current
A magnet on a old CRT TV would distort the colors and image in cool ways along the magnetic field. Nothing permanent unless you left it there for a long ass time. Ahh memories…
Or you had a really strong magnet…
and then you pressed the DEGAUSS button! schwing!!!
I can still hear the noise.
Schtooing!
I got permanent damage on a CRT by playing with some magnets neat it. Never left them around it overnight or anything. They were the magnets from the magnetic beyblade arena lol. The sides of the screen got sort of more red. If bright colors, especially white, were on those areas for a long time they’d get progressively more discolored. It would fade back to its mostly normal dull red shade after some time without the bright white. So it wasn’t the worst damage ever, but it was definitely permanent damage and definitely noticeable.
A magnet can absolutely fuck up a color CRT beyond repair by causing an extreme misalignment of the shadow mask or aperture grille that even a degaussing wand can’t fix. It’d need to be a pretty powerful magnetic field, though. You’d basically have to try to mess it up.
Black and white CRTs are fine, though.
A strong one would fuck it up ‘permanently’, as in it took active measures to restore a good picture (degaussing).
Had an audiophile buddy who had two giant speakers next to his CRT TV.
There were two permanent half circles on either side of the TV. It was bad enough that degaussing didn’t help.
He didn’t care one bit about video performance, just wanted his audio to be the best he could.
The damage magnets did to the old CRT TVs was pretty much reversible.
The damage they do to modern LCD screens is irreversible. But it’s also way smaller than they did to CRTs. The damage they do by strongly snapping pieces of metal around is irreversible too. But if it’s a toy, the magnets are probably not strong enough to damage anything.
Modern electronics are far less concerned with any kind of magnet you might normally run across. A magent powerful enough to be a problem will have labels, signs, and often people to warn you.
Keep strong magnets away from HDDs and tapes, which includes your credit cards (although chip and pin aren’t susceptible). The rest can deal with it, but those storage technologies can be influenced by strong magnetic fields.
CC strips are actually pretty magnet resistant.
I remember in the early to mid 2000s if we were traveling, when we’d put our hotel key cards in the same pocket of our cell phone, the key card would get rendered inert somehow. Dunno if that still happens nowadays.
Yeah, probably the magnetic stripe on the key card (which is essentially a piece of tape) got distorted that way.
A small magnet doesn’t do any harm.
Even in a modern phone there are devices that can be influenced by magnets. Such as the digital compass and autofocus/image stabilization. But the effect is likely not permanent.Pacemakers are one of the few things that can get damaged by magnetic fields AFAIK.
You’re probably fine.
The reason you didn’t wanted magnets near technology before is because we relied on magnetic fields for stuff, so magnets distorted those uses. Nowadays we usually don’t have any magnetic parts on a phone, so unless you have a super strong magnet extremely close to the electronics you should be fine.
Specifically CRT monitors were tiny particle accelerators that shot electrons to a coat of phosphorescent material, they used magnets to redirect the electrons to hit the correct pixels at the right time. So putting a magnet nearby would pull the beam in a different direction distorting the image and shifting it’s colors (because the electrons were now hitting different color pixels). It was not irreversible, usually removing the magnet is all you had to do, but sometimes you might have magnetized something and the beam would remain crooked for a while.
The other thing that would be affected by magnets were hard disks, your PC might still have one so you might not want to put magnets near it, but our phone doesn’t. HDs stored information using magnetic fields into a disk, similar to a DVD except using a tiny needle that would magnetize the disk in one direction to write a 1 and on the opposite to write a 0. Taking a magnet near that would essentially erase all of the data in that disk. Modern storage use very different methods for storing data that don’t depend on magnetism, so you’re fine.
so unless you have a super strong magnet extremely close to the electronics you should be fine.
And, really, when it comes to general electronics that aren’t CRT screens or hard drives, it’s not the strength of the magnet that ultimately matters – it’s how quickly and how intensely the magnetic field changes.
Changes in magnetic field will induce currents in any nearby conductive material, including the circuit board traces and wires of any electronic device. If a strong enough magnetic field changes fast enough, the induced currents will be higher than the components can handle and damage the device. Small, weak magnets are unlikely to ever be a problem, since you’d have to get them moving very fast in order to reach that damage threshold. But, on the other side of the magnetic power spectrum, even extremely strong magnets won’t cause damage as long as they’re moved slowly relative to the device. The more powerful the magnet, the slower you need to be in order to avoid damage.
I have a phone case with a giant neodymium magnet in it. I’ve had it for a few years now. Everything works fine except the Samsung S-pen. When you try to use it you can see the influence the magnet has on your writing and positioning.
It’s fine.
The reason it was an issue with old TVs is because they worked by firing electrons at the screen. Magnets would misalign the internal components resulting in an area of the screen with permanently damaged coloring roughly in the shape of the magnetic field.
The reason it was an issue with old hard drives is because a magnet would read and write the ones and zeroes off the drive platters kind of like a vinyl record player, and any magnetic interference could potentially corrupt the data on the drive.
Modern solid state storage devices are (mostly) unaffected by this problem because they read and write data using electricity instead of magnets.
Nah, it’s not fine. A changing magnetic field still induces current in any conductor. So, swipe a strong enough magnet across your phone in the wrong place and you’ll run a strong risk of doing something similar to ESD (electrostatic discharge) damage.
Not the absolute answer you look for but my phone’s cover is held shut by a magnet.
An unmoving magnet is fine, but move a strong enough one and it’ll induce a strong enough current in circuitry to risk damage similar to electrostatic discharge. Not all components can handle over/under voltage without damage.
