Scanner is a device that converts graphics or image information into digital signals by scanning using photoelectric technology and digital processing technology. It is often used in the workplace, but many users have encountered the problem that the scanner does not recognize the USB port. How to solve it?
What are the reasons why the scanner does not recognize the USB port
The USB function of the motherboard is not activated
Since the Current Windows operating system supports the plug and play function, if the operating system does not respond when the USB scanner is inserted into the computer, you first need to check whether the USB function in the computer motherboard has been activated; If this function is not activated, of course, the USB scanner cannot be automatically recognized.
When checking whether the USB function of the motherboard is enabled, you can restart the computer system, then enter the BIOS setting window, find the "PNP and PCI setup" setting item, and check whether the "USB function" parameter under the setting item is set to "enable". If so, it indicates that the USB function of the motherboard has been enabled. If the "USB function" parameter is set to "disable", It means that the USB function of the current motherboard is not activated. At this time, you must modify the parameter to make its value "enable". Finally, save the BIOS parameters and restart the computer, so that the USB function of the motherboard can be enabled.
Of course, there is a simpler way to check whether the USB function is enabled directly under the windows interface without restarting the computer. As long as you open the device manager window of the system, and then check whether the device list contains the "USB root hub" item. If so, double-click the item. In the pop-up attribute setting window as shown in Figure 1, check whether the current working state of the device is normal. If it is normal, it indicates that the USB function of the motherboard has been activated.
Insufficient power supply of USB port
Even if the USB function of the computer motherboard has been turned on, it can not guarantee that any USB device inserted into the computer can be correctly recognized by the system. This is because each USB device still needs the "drive" of the power supply to work normally. Once the motherboard cannot provide sufficient power to it, the USB device inserted into the motherboard can not be correctly recognized by the computer.
The phenomenon of insufficient power supply of USB port mostly occurs in the relatively old motherboard, or when multiple USB devices are connected at the same time; To avoid this phenomenon, the best way is to insert the scanner into the new computer, or unplug all other USB devices that are temporarily unavailable, and then insert only the USB scanner.
Poor bridging of USB interface
Generally, when the USB scanner is inserted into the USB port of the computer, the computer should be able to automatically recognize the addition of the scanner; If the system cannot automatically recognize the scanner, in addition to checking whether the computer has opened the USB port function according to the above method, it should also check the USB interface of the scanner. If your scanner is not a brand product, its USB interface may be slightly wider than that of the brand scanner. In this way, it is easy to cause poor bridging of the USB interface when the scanner USB interface is inserted into the port of the computer, which is easy to cause the scanner to be unrecognized by other computer systems.
If you encounter this phenomenon, you can use the USB extension cable to connect the USB interface of the scanner. Of course, the specification of the USB extension cable used must be consistent with the USB interface specification of the scanner; If you can't find the extension cable at the moment, you can manually press the USB interface of the scanner slightly inward, so that when the interface is inserted into the USB port of the computer, the bridging of the interface will be better.
In addition, you should also note that when the USB scanner is working, please do not move the scanner or computer at will, so as to avoid accidentally changing the distance between them, resulting in the looseness of the USB connection of the scanner, which will eventually affect the inability of the scanner to be recognized.
Fake death of USB port
Many people think that USB scanners support hot plug function, so they often hot plug scanners at will; As everyone knows, if the scanner is "forcibly" plugged in and out during the working process, the USB interface of the scanner is easy to fake death, which can lead to the burning of the USB interface of the scanner or computer.
Once the USB interface appears "fake death", even if the scanner is tightly inserted into the computer, the computer system will not recognize it for a while and a half. At this time, you might as well enter the device manager window of the system, find the USB scanner item in the device list, double-click the item with the mouse, enter the "driver" tab page in the scanner attribute setting interface as shown in Figure 2, and then click the "uninstall" button to uninstall the original scanner driver, and then restart the computer system, If the system can find the scanner automatically, you can install the USB scanner driver according to the conventional method, so that the fake death of the scanner USB interface will be eliminated. If the system still cannot recognize the scanner after restarting, you need to replace the USB port of the scanner or computer.
Supplement: introduction to scanner
Scanners are usually used for instruments and equipment outside the computer. By capturing images and converting them into digital input devices that the computer can display, edit, store and output. The scanner can take photos, text pages, drawings, art drawings, photographic negatives, film films, even three-dimensional objects such as textiles, sign panels and printed board samples as scanning objects to extract and convert the original lines, graphics, words, photos and plane objects into devices that can be edited and added to documents. The scanner belongs to the input system of computer aided design (CAD). Through the interface of computer software and computer and output equipment (laser printer and laser plotter), it forms a pre screen printing computer processing system, which is suitable for office automation (OA) and is widely used in sign panel, printed board, printing industry, etc.
Related reading: common fault causes and troubleshooting of scanner
1. Only a small part of the whole image is obtained
Troubleshooting: the focus rectangle still stays on the preview image; Only the area within the rectangle is obtained. After focusing, click to remove the focusing rectangle and try again and again to obtain the image.
2. There are too many patterns in the image (noise interference)
Troubleshooting: the humidity of the working environment of the scanner exceeds its allowable range (maybe the scanner is stored or transported outside the allowable range). Let the scanner work within the allowable range. Turn off the computer, turn off the scanner, turn on the scanner first, and then turn on the computer to recalibrate the scanner.
3. The original color is too different from the screen color
Causes and Troubleshooting:
(1) check whether the settings of chroma, brightness and contrast of the screen meet the normal requirements.
(2) check whether the screen setting options of colorlinks are correct.
(3) if fotolook is a plug-in and executed under Photoshop, please check whether the file preferences monitor setup, printing Lnks setup and seperation setup are correct.
(4) assuming the above settings are correct, you can correct the color between the scanner and the display screen.
4. The whole scanned image is deformed or blurred
Causes and Troubleshooting:
(1) the scanner glass plate is dirty or the reflector strip is dirty; Wipe the glass plate with a soft cloth and clean the reflector strip.
(2) the scanned original documents are not always pasted on the document table; Make sure the scanned original is always flat on the platform.
(3) make sure not to move files during scanning.
(4) during scanning, the scanner vibrates due to uneven placement; Pay attention to placing the scanner on a stable surface.
(5) adjust the exposure setting or "gamma" setting of the software.
(6) if the above happens to the parallel port scanner, there may be a problem with the transmission cable. It is recommended to use a high-performance cable above ieee-1284.
5. The scanned image always loses dots and lines when it is displayed on the screen or printed out
Causes and Troubleshooting:
(1) check whether the sensor of the scanner fails or the paper guide mechanism of the automatic document feeder fails, and find a professional for inspection and maintenance.
(3) dust removal shall be conducted for the optical lens of the scanner, and the effect of using a special small vacuum cleaner is the best.
(4) check whether the white correction strip on the scanner cover is dirty and need to be cleaned in time.
(5) check whether the platen glass is dirty or scratched. You can regularly and thoroughly clean the scanner or replace the platen glass to avoid this situation. In the latter case, contact the local authorized technical service center.
6. When scanning printed matter, moire (cross image) appears in a specific area of the image
Troubleshooting: first, let's understand the simple principle of color printing imaging. Try to take a magnifying glass to observe the general color printing. In fact, any picture and text is composed of four colors, namely cyan, magenta, yellow and black. These colors are very small ink dots (a good color printing should have a resolution of 1200 DPI). The arrangement and combination of ink dots can create an illusion for the eyes. For example, if there are more red ink dots in a certain area, the visual system of the human brain will think that this area is red. Such a small dot will be detected by sensitive photosensitive components during scanning, so the scanning result will make the whole picture have various lines, which will seriously affect the quality of the scanned image. The following schemes can be adopted to avoid moire.
(1) select the "color photo" (de texturing) setting in the "image type" or the "de texturing" setting in the "image type" dialog box.
(2) place a transparent page between the document and the platen to defocus the image.
(3) correctly locate the image.
(4) the image size can be slightly adjusted.
(5) select the "clear edge sharpness" check box in the twain of the scanner.