Magnets Erasing Memory Cards?

[boBQuincy]

On AllEars I saw a note from a reader warning about keeping memory cards away from strong magnets such as those in purse latches. The reader claims their memory card was seriously corrupted by the magnet.
I searched websites of memory card manufacturers but could not find any reliable information one way or the other.

Afaik the memory is stored as an electrical charge, not a magnetic field (except on micro drives, which are magnetic) and should be pretty much immune to magnetic fields.

Anyone have any good reliable information before I do my own testing?


boB

 

[I'mNoPrince]

When I work with Mag cards in my Copiers at the libraries. I found that most of the time it was damage to the card and not a (demagnitised) strip causing the problem. If the strip changes state at all the info can't be read. If the start point changes it can't read anything.

This happens with the hard Plastic cards more offend that are know as throw aways . They are made very cheaply and nothing like your DL,CC or Debit cards.They also don't run the start point right to the edge.

Mythbusters did a thing on this and I think only physcial damage to the card caused it to fail.Even static ( from the plastic card rubbing on anything that would cause it ) had no effect and i would think that would be worse then the magnetic field.

I will have to look tha episode up and see.

Looks like Episode 3 Eel skin wallet might have been the one. But not sure.

 

[Groucho]

That sounds a bit fishy to me. I'd file that next to the idea that magnetic bracelets do anything for your health (they don't, it's fraud.)

A quick Google search came up with this.

"There's nothing magnetic in flash memory, so [a magnet] won't do anything," says Bill Frank, executive director of the CompactFlash Association. "A magnet powerful enough to disturb the electrons in flash would be powerful enough to suck the iron out of your blood cells," says Frank.

The Mythbusters bit was more about the magnetic strips in credit cards and the like. On our last trip, my wife's park hopper (regular paper ticket, not part of the "keys to the kingdom" card you get if you have a Magic Your Way ticket) kept getting wiped out. After the third time, they asked if she was keeping it next to a credit card, which she was. She moved it, and no more troubles. The rest of us had ours separate from other cards and had no problems.

Now, that's just anecdotal and is not very scientific, but magnetic strips on cards are a whole different ball of wax.

 

[cpbjgc]

I also don't buy into the "demagentizing" from a purse clasp camera. Doesn't seem plausible for the reason already mentioned.

I used to have a JVC p&s that used a smartmedia card. In the manual it mentioned that a smartmedia card could get wiped by a physical jolt. I was able to confirm this on a trip to WDW after I took a picture of DS and DW with Stitch and I dropped the camera. Luckily, those were the first pics of the trip, and it worked fine after that (albeit with the loss of those first couple pictures ). THe AllEars tip indicated the camera "shifted" during a ride. Perhaps it got bumped?

 

[I'mNoPrince]

I did go off a bit didn't I.

The jolt or even just a bad card could in fact have a momentary short from such a jolt even a slight one if the card is not 100%. This could corrupt only part of the card that holds the pictures and not the part that holds the format info. So you would get no File errors or reformat card warnings.Heck it could even lift the contacts off each other causing a small arch and wiping info.

Unless you have equipment set up to monitor all aspects you can never tell.

I work with electronics every day and just don't see it. Did it happen ,Yes the card was wiped out, But no one will really know why. Thats just one of those mysteries that go with all the others in the electronics field.