question
Ok, this is stupid.
Today I used my credit card to buy something and it was having trouble scanning (which seems to be a problem with this card). The guy at the shop took a white plastic bag and wrapped it around the magnetic strip before swiping it for the fourth or fifth time. And it worked straight away.
He said that sometimes it works when the card otherwise won’t swipe, but he doesn’t know why.
Does anyone know why this would make a difference? It is driving me crazy. If you have any ideas, leave them in the comments.
September 30th, 2004 at 11:31 pm
That’s a good questions, Dan! I’ve had the same experience and I don’t know why this could make it work.
October 1st, 2004 at 12:18 am
I think it’s something to do with increasing static - rubbign the card ona t-Shirt, or even better a fleece seems to have the same effect.
Steve
October 1st, 2004 at 1:27 am
Yeah, someone did that with my card a few months ago. I think it’s to do with static on a smooth/flat surface?
October 1st, 2004 at 5:27 am
It’s likely to be because the bag spaces the card away from the reader and provides a more optimal distance. Static should make no difference - remember it’s reading a magnetic strip. However if the card were too close I could imagine that the magnetic fields in the strip could overlap at the detector and confuse it.
Possibly.
October 1st, 2004 at 6:42 am
Yeah, this is a well known one amongst shop kiddies. A permanent fix is to stick some sticky-tape over the strip.
I believe it has to do with widening the card (giving the reader a firmer contact with it) and spacing the strip a few tenths of a mill off the read head.
It fixes it when it gets partially demagnetised. I think it’s because there is a deep magnetisation when the card is first coded, and a shallow magnetisation caused by holding the card too close to a big magnet. Spacing it off the head might give it a chance to ignore the shallow demagnetisation and read to original encoding below.
October 1st, 2004 at 10:01 am
See, my card has some problems sometimes, but only with some machines (is this a shallow de-magnetisation?) If I go into the bank to complain about it, they scan it to check it and it always works (I always assumed that banks just had better scanners than convenience stores do).
All very interesting
October 7th, 2004 at 9:00 pm
And I had a ‘helpful’ shop assistant stick a strip of sticky tape to my card once (without asking my permission) - meanwhile later that day at the bank, when they saw the sticky tape they exasperatedly explained that it did not do anything and removed it (without asking my permision).
Go figure.