Visioneer Knowledgebase
Visioneer Knowledgebase
Title: USB Device Not Recognized or Unknown Device
Article ID: VIS1419
Updated: 7/2/2007
Operating Systems: Windows 7 / Vista / XP / 2000 / Me / 98
Scanner Models: Visioneer Flatbed: 9520, 9420, 7400, 9320, 9220, 9120, 9020, 9000, 8900, 8800, 8700, 8600, 8100, 7700, 7600, 7300, 7100, 6600, 6400, 7600, 6200, 6100, 6000, 5800, 5600, 5300, 4800, 4500, 4400, 3300, 3100, 3000, PaperPort OneTouch
  Visioneer SheetFed: XP300, XP220, XP200, XP100, RoadWarrior (RW120, PRW120), StrobePro, PaperPort Strobe, PaperPort IX, VX, MX
  Visioneer ADF: XP470, XP450, 9750, 9650, 9650i, 9450, 8650, PT430, PT470, PT680, PT780
  Xerox : X6400, X7600, X4800, X2400DM250, DM250L, DM252, DM262, DM262i, DM272, DM150, DM152, DM162, DM510, DM515, DM520, DM632, DM3640, DM752
 
Symptom:
 
When the scanner is connected to the computer, you receive an error message "USB device not recognized. One of the USB devices attached to this computer has malfunctioned and Windows does not recognize it." or the scanner comes up in device manger as "Unknown device".
 
Problem:
 
These errors are generally caused by a physical communication problem between the scanner and the computer.
Solution:
 
Step 1 - Connect the scanner directly
  1. Connect the scanner directly to a USB port on the back of the computer (or side for notebook computers) using a 6 foot or shorter cable
  2. Using any of the following can cause communication errors:
    • USB hubs
    • Docking stations
    • USB extension cables
    • USB cables longer than 6'
    • Connecting the scanner to one of the computers front USB ports (desktop computer only)
  3. Once the scanner is directly connected, turn the scanner off then back on
Step 2 - Redetect the scanner with Hidden Devices

Windows Vista, XP and 2000 users
  1. Disconnect the power and USB cable from the scanner.
  2. Click here and select "Run" or "Open".
  3. The Windows Device Manager will open.
    • Click on the "View" menu then select "Show hidden devices".
  4. Click the "+" next to "Imaging Devices". This will show all Imaging Devices previously and currently connected to the computer.
  5. Right-click on the Visioneer or Xerox scanner name and left click on "Uninstall".
  6. If the scanner is listed more than one time, uninstall ALL occurrences of the scanner.
  7. IF you see "?Other Devices" in the device manager list, click on the "+" to view the list of Other Devices.
  8. Right click then left click on "Uninstall" for each occurrence of the scanner. The scanner may be listed as any of the following:
    • USB Scanner
    • USB Device
    • Unknown Device
    • 1200 DPI Scanner
    • (Your Scanner Model)
    • (any other scanners or cameras listed here that you no longer use)
  9. Click the "+" next to "Universal Serial Bus Controllers".
  10. Right-click every listing of "Unknown Device" and select uninstall.
  11. Once all instances have been removed from device manager, reconnect the power and USB.
Windows Me and 98 users
  1. Right-click on the "My Computer" icon on your Windows Desktop
  2. Select "Properties" from the list
  3. Click on the "Device Manager" tab
  4. Find "Imaging Devices" and click on the plus (+) next to it to expand the list
  5. Select your scanner, then click on the "Remove" button
  6. IF you see "?Other Devices", click on the plus (+) next to it to expand the list
  7. Select your scanner then click on the "Remove"; button – your scanner may be listed as any of the following:
    • USB Scanner
    • USB Device
    • Unknown Device
    • 1200dpi Scanner
    • (your scanner model)
  8. Close the Device Manager
  9. Unplug the scanner from the computer and from the power
  10. Plug the scanner back in to the computer and power
Step 3 - Use a different USB cable

  • This error can be caused by a faulty USB cable
  • If you do not have a spare USB cable, you can borrow one from another device like a printer
Step 4 - Disconnect any other USB devices

This error can also be caused by a conflict with another USB device.
  1. Disconnect all USB device from the computer (including the scanner), except for you keyboard and/or mouse
  2. Turn the scanner off
  3. Restart the computer
  4. Once the computer has fully restarted, reconnect and power on the scanner
  5. If the scanner works properly at this time, it means there is a conflict with another device on the computer
  6. It may help to isolate the two items by connecting one of them to a USB add-in card
Step 5 - Check the computer's chipset

This problem can also be caused by the computer's chipset. To check the chipset:

  1. Vista, XP and 2000 users: Click here and select "Run" or "Open".
    ME and 98 users: Right click on 'My Computer', select 'Properties' then click the 'Device Manager' tab.
  2. The Windows Device Manager will open.
  3. Click on the plus (+) next to 'Universal Serial Bus Controllers'.
  4. This list will include your computer's chipset.



  5. The follow chipsets are known to have communication problems:
    • SiS 7001
    • VIA Rev. 5 or later
    • Open HCD
    • ALi
  6. If your chipset is one of those listed above or it is only listed as 'Standard', you can try updating the chipset drivers.
    • Contact your computer's manufacturer for more information.
  7. If the problem persists, you may need to use a USB add-in card.
    • This is a PCI card that will add more USB ports to your computer.
  8. For more information about USB chipset issues, see www.usbman.com.

 

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Visioneer provides these technical articles for information use only. The information is generally for a specific scanner model distributed by Visioneer and a designated version of software provided with the scanner. Visioneer makes reasonable efforts to verify the accuracy of content and issue resolution in these technical articles but cannot guarantee any matter including accuracy or results. The articles are provided "as is", without representation or warranty, express or implied, whether of merchantability, fitness for particular purpose, title, or non-infringement. Visioneer disclaims any liability for damages, whether direct or indirect, special, incidental, or consequential, from use of the information in these articles. Visioneer does not evaluate any effect on software and hardware not provided by Visioneer, and therefore disclaims any liability for same. Visioneer is not responsible for the content of support pages accessed through external links. The articles are subject to revision or change without notice.