Credit Card - I Was Once Amused, Now I'm Annoyed!

The magic of magnetism.

Interesting. I suspect several things.

1. The number of samples where this has been tried is too small to be statistically significant to show that it improves the readability.

2. You need to do a number of control swipes without the plastic on the same machine and a number of swipes with the paper or plastic to really be sue what you are seeing is related to the paper or plastic.

3. The paper or plastic may prevent the card strip from getting too close to the sensor. There may be an optimal distance between the card and sensor that the paper or plastic provides.

Actually I've seen this done many times and I'm still amazed that it works. The only explanation I can offer is that the paper or bag simultaneously 1. wipes off any dirt/mag stripe residue from the head and 2. although counter-intuitive decreases the spacing from the mag stripe to the head by increasing the pressure due to the extra thickness provided by the bag or paper. Both actions bring the stripe closer to the head and provide a higher probability of a good read.

Wiping your card through a reader moves a little rubber wheel that times the wiping. Normally the inaccuracy in this timing mechanism is not a problem since the magnetic signal is strong and distinct. When the magnetic signal on the card gets a little smeared the timing gets much more critical. Increasing the material thickness improves the timing wheel movement accuracy.

Are you saying the additional thickness allows the wheel to make better contact with the card, making it spin more accurately? Would masking tape, with its rougher surface be a better choice?

It might, but a teller altering a customers credit card does not sound like a good idea to me.

I always wondered about that. I think that is the answer. Moving the card slightly away from the read head acts as a low pass filter, removing the noise caused by scratches in the magnetic stripe.

I'm not sure tape is a good idea. If it comes loose, it could gum up the reader.

GA! Thank you for the explanation.

I suspected something like this but now it is confirmed.

I had a problem card once, and was mystified that the clerk so casually wrapped one of their plastic bags around it and swiped it once. Problem solved.

the clerk placed it in folded plain white paper and it read just fine

Yes, this happened to me. I'm not yet sure why it changed colour and it had a different name on it, but it happened.

Not sure. Is the thing scuffed to the touch ? That might somehow alter how it 'reads'. I've had mine rejected a few times, and a light rub with edge of jumper or whatever seems to sort it. Given the amount of fraud, why do they issue these things with several years validity date ?

It's most unfunny to have that happen, it leaves you wondering if you may have been scammed in some way. I'd get a new card if I was you (interesting as the topic is). Credit card companies are not noted for explaining flaws in the system.

Send the offending card to me via CR4 and I will try investigating. It will help if you also mail me your date of birth and address, but I can probably work off the card alone. Our name is mob, and we are many.

You can easily buy the gear to read and replicate a card, but I'd ditch that financial pothole.

Don't forget, it might be handy to have my social security number!!!!!

While you're at it, can I also have your passport.

Hi. You should replace it. It ( the strip) is worn-out or defective. Bank should cover the cost - it is their equipment's malfunction…

The layer of plastic will "push" it closer to the reader.

As a matter of interest - which country are you from ? Here in Africa - we are using micro-chipped cards for the last 3-4 years ….Much easier, error-proof and more secure J

I think Sid was jurios curious about the technical reasons, and has probably already ordered a new card.

Good point about a layer of whatever pushing the card closer to the scanner. I'm also wondering if the scanning machines also get grubby ? Umpteen thousand cards swiped must leave some sort of residue, either form the card or grease (from fingers) on the card itself.

My wallet, apart from being devoid of real cash, is chocked with cards of various sorts. I don't know why the magnetic strips are not laminated in some way to better protect them.

I'm currently asking CR4 members to send me their cards and Pin numbers so that I can evaluate this. If the responce is good enough, I'll post feedabck from my tropical Island in the Pacific. Welcome to the madhouse, Viktor.

So called 'chip and pin' is now widespread, though there are many reports that it's not as secure as banks would have us believe. Obviously, banks are not going to openly admit this (in the same way that they are very quiet about credit fraud in general). There are many sources of info on this, but the article here seems as good as any.

Kris don't confuse chip pin with chip pan and deep fry your credict card...
Del

- do you think NatWest will sue me over the ATM incident ? I tried to pull out the spuds, honest. I selected 20, and all I could hear was a strange spluttering sound. Mabe I shoud have set it to 40. That slot for the bacon doesn't seem to be very well designed either. The egg frying space was working very well a few months ago, but they seem to have switched it off. I'm guessing they want to save on Winter fuel bills. I'll write and alert them to all this - there's not even a sensible toast slot

The read head gets dirty.There is a cleaner card available designed to clean the head.It is the same size as a credit card,but has a soft fuzzy surface soaked in alcohol(Anhydrous Isopropyl ). Pass it through the slot several times,reverse the card,then do it again.You will have 4 cleaning cycles if you use top,bottom,front and rear of the card.Look at the dark streak on the card from all the gunk removed.The last wipe should be clean.

Most read errors will vanish after this procedure.Once a day in heavy usage areas will prevent future problems.

Good idea, but that's not the job of us punters who use the cards, it's down to the card reader owners. They should do it more often!

I was hoping some of the punters would pass this info along to the owners.I carry one with me,, and after I use it,they want to know where I got it,so word is spreading about proper maintenance of the readers.They never heard of a cleaning card so they did not RTFM.

Spread the word next time it occurs.Preview Comment

It's only happened to me occasionally when it needed several swipes, but I'll tell them next time. Where can you get these cleaner cards?

Don't know what's on your link, all I got was # and a message "Inernet explorer has modified this page to help prevent cross-site scripting" - whatever that means!

There are many sources on the net..Google "card reader cleaning card"

Here is one such link:

www.staples.com/CardKleen-Magnetic-Head-Cleaning-Cards/product_587189

I would think the additional layer (paper or plastic - where have I heard that...) would diminish the ability to read the strip.
Actually it diffuses the laser light thru the scratches on the card.

the problem will soon be solved after our? government installs a micro-chip in your arm.