03-10-2016 06:26 PM
two weeks ago, after i bought this sd card, I formatted it to ExFAT and plug into my surface pro .
But I don’t know why it just can save the small size files (around 10 MB), if this card saves some bigger than 10MB Files, those file will not be read again. I had tried to take this sd card to other PCs, even desktop or notebook with win7, win8, win10, and then format the sd card and save files for testing again and again. The same result will happen.
does the sd card has problem?
Remark: this sd card cannot format to NTFS, I also try to format it to NTFS with different PCs and different windows version.
05-08-2017 07:59 PM - edited 05-08-2017 08:09 PM
This sounds like a classic case of a counterfeit memory card!
Memory cards have a control chip that can be programmed. These chips "tell" the system how much memory is available on the card.
Unfortunately, unscrupulous sellers (mostly from China & Hong Kong) have discovered that it is possible to take a lower capacity memory card, and re-program the chip to "tell" the OS that the card has more capacity than it actually does.
I have run into this numerous times, and most often on cards and USB keys ordered through eBay.
Because of this, every time I purchase a new memory card and regardless of where I purchase it from, I always test it immediately with a program called "H2testW". It is available free, and has saved me quite a few problems in the past.
As I write this, I am currently testing a brand new SanDisk Ultra 200 GB microSDXC UHS-I Card that I just purchased for my Microsoft Lumia 950 smartphone.
There is an interesting article on the web about this phenomanon. It is available at:
It contains a link to the "H2testW" program, so before you drive yourself nuts trying to find out why you have these problems, I would suggest that you download the test program and run it on your 'problem' card.
IF your card was purchased through eBay, and is not too old, you can always report a counterfeit item and file a claim to get your money back. If it was purchased through a reputable dealer, I usually take a screen capture of the H2testW results and take the card back for an exchange or refund as a "faulty device".
Reputable stores are not usually out to defraud you, but the same can not always be said of their suppliers. "Store specials" are often put on because the store owner "got a good deal" and is honestly trying to pass some savings on to their customers, and they have to take on trust that the items THEY are sold are legitimate, because they cannot unpackage them all to test each and every one.
The counterfeiters have become quite good at duplicating manufacturers' packaging, and they can make quite a profit by selling say - 8GB memory cards, as 64 or 128 GB cards and they usually get away with it. This is because the end user normally does not find out the card is 'faulty' right away, and then more time passes as they try to get the counterfeit card covered under the real manufacturers' warranty (which, of course, never happens, as it is not the manufacturers' product - so no coverage). By the time the purchaser realizes that they have been cheated, it is usually too late to take any form of action.
Anyway, I hope this helps you to at least determine if your card is "real".