Shenzhen YEHENG Electronic Co., Ltd.
Time： 2019-12-05 09:34:43
Not long ago, a customer brought a 500GB mobile hard disk and claimed that the data was damaged and needed to be repaired. During the repair, the owner of the electrical maintenance shop found that the hard disk was not used normally. If you want to copy a movie to it, you can only play the last five minutes. Driven by curiosity, the boss took the hard disk apart. Absolutely, this hard disk is actually composed of a 128MB U disk and two large nuts. You see here, most people often laugh it off, but this kind of encounter may happen around you. Nowadays, mobile storage products are getting cheaper and cheaper, especially the U-disk products, which can be seen everywhere from the electronic market to street stalls. But at the same time of low price, can the quality of these low-cost U-disks be guaranteed? Not long ago, a friend's USB drive always had problems of data loss or unable to open files. In the process of helping to repair the USB drive, we found that it was a USB drive expanded by software. Next, we will unveil the mystery of this USB drive.
From the appearance, this is a very common direct plug-in U-disk. On the side of the product, it is marked that the capacity of the U-disk is 2GB, and the anti-counterfeiting label and service hotline are all available. It is difficult for ordinary people to distinguish the authenticity of this U-disk only from its appearance.
Connect the computer, and the computer can correctly recognize the USB flash disk. First of all, format this USB flash disk and check its properties. The total capacity is 1.97gb. Seeing this, I have begun to doubt whether this USB flash disk is an expansion disk. Because, due to different algorithms and flash bad block and other factors, the actual available space of 2GB USB flash disk is about 1.85GB, and the available space of this USB flash disk is 1.97gb, which is somewhat abnormal.
Generally, there will be problems when reading a single large file from the USB flash disk. Here, copy a 1.1GB video file to the USB flash disk, and then open it in the USB flash disk. At the beginning of the play, everything is normal, but when the play reaches 17 minutes, the player displays no response, the video screen pauses, and the play progress cannot be selected through the progress bar.
In order to verify the conjecture of expanding the U disk, I recommend you to use the testing software to test the expansion and data integrity of the U disk, such as mydisktest and h2testw.
The test result is consistent with my guess. The software shows that this USB flash disk is an expansion disk, and the actual capacity is only 139mb, which may be generated by the expansion of 128MB or 256MB USB flash disk. The data integrity test also shows that the data verification pass rate of this USB flash disk is only 7.6%, with about 152mb of complete data.
Next, I test the capacity of the U disk, and through the capacity test, I get 640MB of usable capacity. This brings up new problems. Is the real capacity of this USB stick 128MB, 256MB or 640MB? To restore the real capacity of the USB flash disk, you need to borrow a group of USB flash disk mass production tools. The mass production of U disk is different from the format we often say. The mass production of U disk is a bottom-level format, which will write data to the main control chip of U disk, and then format the U disk with the corresponding information of the chip, which is equivalent to the last process before the U disk leaves the factory. In order to carry out mass production operation on the USB flash disk, it is necessary to know the model of the main control chip used by the USB flash disk. Through software testing, the mass production of USB flash disk is completed and the original appearance of USB flash disk is restored. The actual capacity of the expanded U disk restored by mass production tools is astonishing. The software shows that the actual flash memory capacity of this U disk is 512MB, but the bad sector is as high as 50%. That is to say, half of the bad sectors are shielded, and the actual capacity that users can use normally is only 256MB. It seems that the expansion of U disk is not only a software fraud, flash memory particles also use the defective products eliminated by the factory, which is commonly known as "black chip". So you can't buy a U disk or a memory card cheaply
Summary: the U-disk is very popular now. Because of its small size, portability and low price, it is welcomed by users, and it also gives illegal traders the opportunity to use the Shanzhai expansion U-disk to store important data or data, which often causes irreparable loss. Many friends have experienced the event of data loss caused by using the Shanzhai U-disk or memory card 。 Therefore, it is suggested that readers should go to the regular stores or digital shopping malls as much as possible when purchasing U-disk. If they like online shopping, they should also go to the trustworthy shopping malls. In nine out of ten cases, the U-disk or memory card peddled by street vendors is the product of Shanzhai expansion. You must not be greedy for a small price and suffer a big loss. You can also refer to the method mentioned in this article to check whether the USB flash disk or memory card on hand is a Shanzhai expansion product.