What if the computer doesn't recognize the USB device?

Now we are using more and more USB devices, and there are no fewer problems, software hardware aspects of the problem, then we analyze the USB device and troubleshoot.





1. Front usb cable Connection error. This type of failure occurs when the USB cable on the motherboard corresponds to the front USB connector on the chassis, which is also quite dangerous, because the positive and negative connection is likely to cause the USB device to burn. So as far as possible with the chassis behind the USB interface, but also less use extension cord. It may also be a problem with the fracture, change the USB port to see.


2.USB interface voltage is insufficient. When the mobile hard disk is connected to the front USB port, it is possible that the system does not recognize the fault of the device. The reason is that the power of mobile hard disk is relatively strict, the front interface may not provide enough voltage, of course, inferior power supply may also cause this problem. The solution is to move the hard disk do not connect to the front USB interface, replace the inferior low-power power supply or try to use the external power of the hard disk box, if there are conditions.


3. Compatibility issues with the motherboard and system. Hehe This kind of fault is most famous is NF2 motherboard and USB compatibility problem. If you encounter this problem on the NF2 motherboard, you can install the latest NFORCE2 dedicated USB2.0 drivers and patches, the latest motherboard patches and operating system patches, or not, try refreshing the motherboard BIOS can generally be resolved.


4. System or BIOS problem. USB devices cannot be identified in the system when you disable USB in the BIOS or operating system. The workaround is to turn on the options associated with the USB device. is the boot press F2 or DEL key, into the BIOS, the Enable USB device select Enable.


5. Pull plug to be careful, read and write must not pull out, or it may burn the chip. XP in the taskbar more than a USB device icon, open the icon will be shown in the list of U disk devices, choose to deactivate the device, and then you unplug the device, this will be more secure.


actually judge the software hardware problem is very simple, in another machine or another system try on it. Some small problems may be formatted with specialized software. And to remind everyone to choose fat when you format windows, do not select FAT32.


prompts unrecognized USB device repair





Unrecognized USB device: Unknown USB Device. A lot of people have encountered a problem, the so-called "unrecognized" for the operating system, or a problem with the driver, or a USB device problem, or the computer and USB device connection has failed, the solution is to solve the problem from the beginning.


for different devices will have different processing methods, understand the USB device to the normal working conditions and some factors that may affect the normal operation of USB devices, will help solve the problem.


The following are some of the conditions that ensure that the USB device works:


(1) The USB device itself has no problem--it can be tested on other computers to ensure it works;


(2) USB interface does not have any problem--can be tested on this interface by connecting other USB devices;


(3) USB device driver has been properly installed, if there is a detailed description of the book of the USB device, be sure to carefully review the appropriate documentation, follow the instructions to install the appropriate driver; Windows 2000 after the operating system to identify most of the USB devices, Windows 98 the previous operating system can install a USB device with its own drive or install a generic USB device driver.


The following are some scenarios that may affect the normal functioning of USB devices:


(1) USB device has failed (the same condition can be used before, now there is a problem);


(2) USB interface is problematic, such as a. USB Front Interface Polarity Reverse, this may cause the USB device to burn, so be sure to carefully look at the motherboard instructions, to prevent the wrong answer B. Lack of interface voltage, some mobile hard disk often have such a problem, the USB interface behind the host is usually more reliable than the front USB interface; c. motherboard and operating system compatibility problems, install the latest motherboard driver to maximize the avoidance of such problems; USB devices are disabled in D.bios, possibly by changing the BIOS The setting to be resolved; E. Operating system problems can be resolved by reloading the operating system;


(3) USB driver is problematic: if there is a problem with the driver, you should ensure that the latest driver for the appropriate model of the device is installed or that the operating system does not require a special driver to be installed, and that the latest driver can be found by the home page of the manufacturer of the online device.


When there is a problem with the USB device, in addition to looking for a solution based on the actual error message, it is also important to look closely at the specific brand, model, manufacturer of the USB device, including this information when searching for results, and to find the solution more easily. Like some plug-and-pull effort requires a frequently connected USB device temporarily fails, the operating system is constantly "unrecognized USB devices" such as annoying prompts, you can temporarily close the Universal Serial Bus controller in the appropriate USB port or prohibit the corresponding USB device.


about unrecognized USB devices


Computer Settings


inserted, will be in the lower right corner of the computer is trying to connect some of the USB device information, and sometimes pop-up dialog box to allow users to choose, some users have not seen the point is not, or because some of the computer's initial setup problems, prohibit some of the USB features.


Solution: Right click "My Computer", select "Properties"-"Hardware"-"Drive Signature", choose "Ignore" here, click "OK". Then plug in the MP3, or not, and then right-click "My Computer"-"Properties"-"Hardware"--"Device Manager", find "Universal Serial Bus Controller", right-click, and "Scan for hardware changes."








the voltage problem of the equipment itself


because now the trend of MP3 is to reduce costs, so the company constantly adopt new programs, new master, new Flash chip, not to say that these new things on Jerry, the problem is that these new things often require long-term debugging to achieve the best, But the market situation can only allow MP3 factory test can be in a computer interface on the machine to put into production, so often appear not online, off the disk phenomenon. 3lian.com


this case will require users to try several times, plug different USB interface, separate with a good quality USB cable (generally thicker the better, better copper than iron), and then ensure that the MP3 power supply is normal (with the charger to fill the electricity and try again).


system error "Unrecognized USB device"


fault phenomenon: The use of U disk when the computer unexpectedly power off, reboot after the U disk can not be used normally, plug the system on the error "Unrecognized USB device." The same error message will be prompted with other USB interface devices that used to be normal. Plug the USB device into the other USB connectors on your computer to work properly.


Analysis failure: From the phenomenon, the USB device and motherboard interface are not damaged, suspected to be accidental power loss caused system setup error.


problem handling: From the control Panel into the Add and Remove Hardware window, remove all USB devices, reinstall the USB device drivers that you need to use. Restart the computer, U disk and other USB devices plug in the original fault interface to work properly. Unrecognized USB device-laptop hard drive failure and removable hard drive, plugged in front USB connector, unrecognized.





This situation, a big reason is the power supply problem. Because the USB hard disk in the work also need to consume a certain amount of electricity, if directly through the USB interface to take electricity, it is likely to appear power supply. As a result, almost all mobile drives come with a separate external power supply or a PS2-turn interface that is powered by a keyboard. At this time as long as the prior connection to the external power supply or through the PS2 to connect with the keyboard, to ensure that the mobile hard disk to provide enough power after the test, then should be normal use of it. It is important to note that it is recommended that you make sure that you have enough power before using a removable hard drive, or you may be damaged by a lack of power.


for a friend who has never used a USB add-in, it is possible that the system cannot detect a USB hard drive even if the driver is properly installed, mainly because the motherboard default CMOS port is turned off, and if it is not set to open, Then Windows naturally cannot detect the removable hard drive. To solve this problem, we can reboot, enter the CMOS Setup window, and in the "Pnp/pci CONFIGURATION" column, "Assign IRQ for USB" is set to "Enable", This allows the system to assign an available interrupt address to the USB port.

The
may also be incompatible with the USB interface type, causing the removable hard drive to be unusable. For example, the computer configured USB interface is 1.1 standard, and the purchase of the mobile hard disk is the USB 2.0 standard interface, which requires connecting the computer and mobile hard drive connector must support the USB 2.0 standard. Because a high-speed mobile device is plugged into a low-speed hub, the device may not be installed properly, and some friends use a USB drive while using a mobile hard disk, which makes it easy to use the 1.1 standard connector that comes with the USB 2.0 standard, which results in the correct identification of the mobile hard drive. This failure can be resolved simply by replacing the connector with the USB 2.0 standard.