Basic usage of u disk
U disk has a USB interface and is a USB device. If the operating system is Windows 2000/XP/2003/Vista, the system will automatically recognize the USB flash drive by plugging it directly into the USB interface on the front panel or the back of the chassis. If the system is 98, you need to install a USB flash drive to use it. You can find the driver on the attached CD or the manufacturer's website.
When you first use the USB flash drive, the system will report and find new hardware. After a while, you will be prompted that the new hardware has been installed and can be used. Open "My Computer" and you will see an additional icon named "Removable Disk". After this step, if you use a USB flash drive in the future, you can directly open "My Computer". At this point, notice that a small icon will appear in the lower right corner of the screen, indicating a USB device. U disk is one of USB devices. Next, you can save and delete the files on the USB flash drive as usual. However, it should be noted that after using the USB flash drive, close all windows, especially those about the USB flash drive. Right-click the USB device icon in the lower right corner before correctly unplugging the USB flash drive, then left-click "Remove Hardware Safely", press the "Stop" button, and then click "OK" in the pop-up window. When the prompt "You can safely remove the drive now" appears in the lower right corner, you can unplug the USB flash drive from the chassis.
The invention of u disk
When USB flash drive replaces floppy disk as people's conventional mobile storage tool, few people know that USB flash drive is not a product name, but only a registered trademark of flash drive. The company that invented the world's first flash drive and obtained the basic invention patent of the global flash drive, its founder and one of the invention patent holders, Lu, the president of Harbin Netac Technology Co., Ltd., settled in the Pioneer Park for Overseas Students in Harbin Development Zone at the beginning of his business, and jointly led the development of the global mobile storage industry with Shenzhen Netac Company.
Netac's only disk with U disk as its trademark is the world's first new generation storage product based on USB interface and using flash media. USB flash drive is the only original invention patent in the field of computer storage in China in recent twenty years, which belongs to China people.
U disk, USB interface, plug and play
Generally speaking, USB is one of the interface types between peripheral devices and computer hosts. In addition to USB interface, there are parallel bus and other interfaces. However, USB interface has a great advantage that makes it very popular in this field, that is, devices with this interface can be plugged and played on computers (sometimes called hot plug).
When the computer is turned on, the peripheral equipment should be turned on first, and then the power of the host computer should be turned on, and the order of turning off is just the opposite. The reason why this boot sequence should be followed is that before the computer starts, all peripheral devices must be powered on to get ready, and then wait for the host to check these devices one by one and install the corresponding software. Only in this way can the computer run normally, otherwise the peripheral equipment may be unavailable or the computer cannot recognize the peripheral equipment.
However, the appearance of USB interface changed this situation. If a device is a USB interface, it can be plugged into the computer host at any time, no matter what state the computer is in at this time. If you want to take this device away, you can safely take it out of the computer according to the standard operation, which undoubtedly provides great convenience for people's study and life.
Therefore, it can be seen from the name of the U disk that this storage disk is a USB interface. Because this storage disk is a USB interface, this storage disk can be plugged in and played on the computer, which means that this storage disk is removable and can be carried around. Therefore, the broad U disk actually refers to mobile storage devices, and the narrow U disk only refers to flash drives.
Flash disk refers to a removable storage disk that uses flash technology to store data and information. Flash memory technology is a storage technology that has just emerged in the computer field for several years. Compared with the traditional electromagnetic storage technology, it has many advantages: first, this storage technology has no mechanical movement in the process of storing information, which makes it run very stably, thus improving its seismic performance and making it the most anti-vibration device among all storage devices. Second, because it doesn't have high-speed rotating disks like floppy disks, hard disks and optical disks. Its size can usually be made very small. Now MP3 players can be made very small because of this storage technology.
For example, some people say that he has a USB flash drive, which may be just an ordinary mobile hard disk, or a micro hard disk that has just appeared in recent years, or a USB flash drive. Of course, as mentioned above, the current USB flash drive generally refers to a USB flash drive, so we usually understand that what he owns is a USB flash drive.
Online storage-"network USB flash drive"
It has the functions of "upload" and "download" of breakpoints, which not only realizes the download of large files, but also has the function of breakpoint continuous transmission, which can transmit files in segments and greatly save transmission time.
"u disk parasite" (Checker/Autorun)
"U disk parasite" is a worm virus spread by mobile devices such as U disk. autorun.inf is used to automatically play files. Autorun.inf files generally exist in the root directory of U disk, MP3, mobile hard disk and hard disk partition. When a user double-clicks a device such as a USB flash drive, the file will use the automatic playback function of Windows system to execute the virus program to be loaded first, thus damaging the user's computer and causing losses to the user's computer.
Expert advice: users must scan the USB flash drive with antivirus software before using it, and then open it after confirming that it is non-toxic.
U disk fault and its solution
When repairing the following faults, first of all, we should eliminate the damage of USB interface, virtual welding of PCB board and normal USB extension cable, and then make maintenance judgment.
1.The USB flash drive does not respond when inserted into the machine.
Maintenance ideas: according to the fault phenomenon, the U disk machine does not work, and the conditions that the U disk tool should have are the focus of our maintenance. No matter what scheme of USB flash drive wants to work, the following conditions must be met:
(1) power supply is divided into power supply required by master control and power supply required by FLASH. These two are keys, and the U disk circuit is very simple. If there is no power supply, it is generally the fuse inductor or the 3.3V voltage stabilizing block that is damaged. Speaking of voltage stabilizing blocks, let's stop here. It has three pins, namely power input (5V), grounding and power output (3.3). The working principle is that when the input pin inputs 5V voltage. As long as we find a place without power supply, this problem will be well solved.
(2) Clock, because the host can only work at a certain frequency, and the communication with FLASH also needs to be transmitted by clock signal, so if there is no clock signal, the host will definitely not work. When checking this circuit, in fact, the clock generation circuit is very simple, just check the crystal oscillator and its peripheral circuits, because the crystal oscillator is afraid of rubbing and the U disk is easy to fall to the ground, which will damage the crystal oscillator, so just replace the same crystal oscillator. Note: the crystal oscillator cannot be measured, and the best way to judge its quality is to change a good crystal oscillator.
(3) Master control. If the above two conditions are normal, the master control chip is damaged. Just change the main control.
2. Insert the USB flash drive into the computer and prompt "Unrecognized device".
Maintenance ideas: for this phenomenon, first of all, it shows that the circuit of the U disk is basically normal, but there is a fault in communication with the computer. For communication, you need to check the following points:
(1) USB interface circuit, this circuit has no special components, just two data lines D+ D-, so when checking this circuit, you only need to measure whether the line between the data lines and the main control circuit is normal. Generally, two resistors with small resistance are connected in series between the data line and the main control circuit for protection, so it is necessary to check whether the resistance values of these two resistors are normal.
(2) Clock circuit, because the communication between the U disk and the computer should be carried out at a certain frequency. If the working frequency of the U disk and the computer can't be synchronized, then the system will think that this is an "unrecognizable device". At this time, the crystal oscillator will be changed. And there are many examples of crystal vibration damage in actual maintenance!
(3) Host, if the above two checks are normal, it can be judged that the host is damaged.
3. You can recognize the USB flash drive, but when you open it, you will be prompted "The disk is unformatted" but the system cannot format it, or you will be prompted "Please insert the disk". Open the USB flash drive, which is full of random codes, and the capacity does not match itself.
Maintenance ideas: for this phenomenon, it can be judged that there is not much problem with the hardware of the U disk itself, but there is a problem with the software.
Solution: Just find the repair tool of the master control scheme. This depends on everyone, what is the main control scheme of the USB flash drive.
The failure of U disk is generally due to the poor performance of flash memory or the phenomenon that bad blocks can't be written and stored in files. Unlike MP3, USB flash drives don't have firmware, but some manufacturers put their own software in them. If they are low, they will be gone.
Tell you a very simple method, that is, when the main control is damaged or the corresponding repair tool can't be found, you can use the USB flash drive kit to make a new USB flash drive. The method is to remove the flash of the faulty machine and put it on a new PCB. U disk kit includes (PCB with main controller (1. 1/2.0) and a set of shell), which is very simple to maintain and more convenient for data recovery.
Life of u disk
The erasable times of the USB flash drive are the normal life of the USB flash drive. Generally, a USB flash drive can be erased 1 0,000 times or more.
Maintenance of u disk
Correct plugging and unplugging of U-disk: Never unplug the U-disk when the indicator light of U-disk flashes rapidly, because the U-disk is reading or writing data at this time, and unplugging it in the middle may cause damage to hardware and data.
Don't close the related program immediately after backing up the document, because the indicator light on the U disk was still flashing, indicating that the program was not completely finished. At this time, pulling out the USB flash drive will easily affect the backup. Therefore, after the file is backed up to the U disk, it will take some time to close the relevant programs to prevent accidents; Similarly, when the system prompts "Cannot stop", don't pull out the USB flash drive easily, which will also cause data loss.
Pay attention to place the U disk in a dry environment, and don't expose the interface of the U disk to the air for a long time, otherwise it will easily cause surface metal oxidation and reduce the sensitivity of the interface.
Don't always plug a long-term unused U disk into the USB interface, otherwise, on the one hand, it will easily lead to aging of the interface, and on the other hand, it will be a loss to the U disk.