USB fault solution

USB is a channel for U disk to communicate with the computer. It plays a very important role in the application of our data. If the USB is faulty, the U disk will not be used, so it must be solved. .

Fault 1: USB disk plugged into the computer, prompt "Unrecognized device" Fault

Fault analysis: For this phenomenon, the first point is that the U disk circuit is basically normal, but only There is a fault in communication with the computer, and the following points should be checked for communication:

(1) U disk interface circuit, there is no special component of this circuit is two data lines D+ and D-, so When checking this circuit, as long as the line between the data line and the main control is normal, generally two small resistance resistors are connected in series between the data line and the main control circuit to protect the ground. Check if the resistance of these two resistors is normal.

(2) The clock circuit, because the U disk and the computer communicate with each other at a certain frequency, if the U disk's operating frequency and the computer can not be synchronized, then the system will consider this to be an "unrecognized" Equipment " At this time, it is necessary to change the crystal.

(3) Master, if the above two checks are normal, then it can be judged that the master is damaged. Then there is basically no sense of maintenance.

Fault 2: After troubleshooting the USB storage device itself, the unrecognized phenomenon is usually caused by the following aspects; First, the front USB cable is connected incorrectly. When the USB cable on the motherboard and the front USB interface on the chassis are connected, the fault will occur when the positive and negative terminals are reversed. This is also quite dangerous because the positive and negative reverse may cause the USB device to burn out. It will also burn the motherboard. The second is the compatibility of the motherboard and system. The most famous of these types of failures is the compatibility of the NF2 motherboard with USB. If you are experiencing this problem on the motherboard of NF2, you can install the latest nForce2 dedicated USB2.0 driver and patch, the latest motherboard patch and operating system patch, or try to refresh the motherboard BIOS. Can solve. The fourth is a system or BIOS issue. When you disable USB in the BIOS or operating system, it can happen that the USB device cannot be recognized in the system. The workaround is to turn on the options associated with the USB device.

Fault 3: Under Windows XP operating system, the system prompts that new hardware has been found and the hardware is installed normally, but the drive letter of the flash drive cannot be found, and the flash drive light is constantly shining. Fault analysis: This kind of fault is generally caused by illegal operation. It is considered that the flash drive can support hot swapping. Therefore, if the mobile device is not properly deleted, the plugging operation is directly performed. Incorrect operation is caused. The root cause of the disappearance of flash memory.

Troubleshooting: Go to the Windows system, right click on "My Computer", select Properties to enter "Device Manager", and see more under the "disk drive" A "Ne-tac Onlydisk" device, double-click to enter, and see four new options in the pop-up window: "Disconnect"", Delete ", "Sync Data Transfer" and " ; Int 13 unit ", carefully observed that the "can be deleted" option is unchecked. Restart the computer by typing in the space before the "deleteable" option and clicking OK.

Fault Summary: This fault is still caused by the misuse of the flash drive. It can be seen that the probability of failure due to improper use of the flash drive is very large, so everyone must use it. Follow the rules to ensure the normal use of memory.

Fault 4: You can recognize the U disk, but when prompted, the disk is not formatted "but the system cannot format it, or the prompt "Please insert the disk", open the U disk. Garbled characters, capacity does not match itself.

Fault Analysis: For this phenomenon, you can judge that the hardware of the U disk itself is not too much problem, just a software problem.

Solution: Find the repair tool for the master solution and use it. This is up to everyone to see the main control plan of the U disk.

Fault 5: When a device such as a USB interface is connected, an unidentified device is displayed.

Fault Analysis:

(1): The driver is not installed correctly. Please read the driver installation procedure in the following manual carefully. Now the driver is usually in the device. If it is closed, install half of it, and to a certain extent, it will prompt to turn on the power of the device. At this time, the device can be powered on, and the driver can automatically recognize it and proceed to the next step.

(2): After the cause is removed, the device is also not identified. Then there may be a situation where the USB power supply is insufficient. Usually I will try to replace the line with a good point. No, then you can only adjust the speed of the USB interface in the bios, reduce the speed to the USB1.1 mode, can solve the problem of insufficient power supply, although there is no impact on large equipment such as printers, but the propagation speed of the U disk will be greatly reduced.

Fault 6: When the USB hard disk is connected, the unidentified device is displayed.

When the mobile hard disk is connected to the front USB port, the system may not recognize the fault of the device. The reason is that the power of the mobile hard disk is relatively high, and the voltage is relatively strict. The front USB interface is through the line. When the cable is connected to the chassis, it will consume a large voltage during transmission. Therefore, when using the mobile hard disk, pay attention to the USB interface that comes with the rear motherboard as much as possible. Otherwise, you can use the external power adapter. Provide separate power supply. Of course, on some older motherboards, independent power must be used for normal use of USB devices.

The fault of USB is not too much. As long as the patience is eliminated, the fault can be solved quickly. According to the above solution, similar problems will not be a problem.