MORE INFORMATION
Because USB devices are Plug and Play devices, there is
little that you can do to control or configure them. However, you can trace
most USB problems to one of the following conditions:
- Malfunctioning or incorrectly configured
hardware
- Malfunctioning, incorrectly configured, or missing device
driver
- Mismatched cabling
- Out-of-date firmware or basic input/output system
(BIOS)
- Improperly configured root hub
You can use the following troubleshooting tips to check for
each of these conditions to help you resolve USB device issues.
Malfunctioning or incorrectly configured hardware
Typically, if you plug a malfunctioning or incorrectly-configured
device into a USB port, it causes the computer to stop responding (hang). In
the majority of these instances, you must physically turn off the computer and
turn it back on to reset the bus. Note that it may be more difficult to
identify which device is malfunctioning or is incorrectly configured. If
another computer that you know is working correctly is available, try to plug
the device into that computer to see if you encounter the same issue.
If the device is plugged into a secondary hub, unplug the device
from the hub, and then plug the device directly into the root hub.
Many hardware problems (such as high or low power, bandwidth shortage,
malfunctioning or incorrectly configured firmware, and so on) can cause issues
to occur.
Check Device Manager to be certain that the root hub is
functioning correctly. If the root hub is displayed with an exclamation point
(!) in a yellow circle, verify that the BIOS is assigning an interrupt request
(IRQ) to the root USB controller. This is required for the device driver to be
loaded.
For
additional information about how to use Device Manager to troubleshoot hardware
issues, click the article number below to view the article in the Microsoft
Knowledge Base:
133240 Troubleshooting Device Conflicts with Device Manager
If no devices work when you plug the devices into
the root hub, verify that the power requirements of the bus are not being
exceeded. USB devices can draw a maximum of 500 milliamps for each connection.
If a device attempts to draw more power than this, the specification recommends
that the computer should be able to disable that specific port until the
computer power is cycled (this is called "suspending" the port). In addition,
if the device draws less than 50 milliamps, the port never becomes active.
Check the
Power tab in USB Root Hub properties to check the power usage of the
USB bus.
Malfunctioning, incorrectly configured, or missing device driver
When you plug in a USB device, the computer should load and then
configure the device without ever requesting a device driver (assuming that the
device falls within the defined and supplied class drivers). If the computer
prompts you for a device driver, check with the manufacturer of the device to
determine if a driver is available.
Mismatched cabling
There are two types of USB cables, high speed and low speed.
Low-speed cables differ from high-speed cables primarily in their shielding. If
you plug a high-speed device into a low-speed cable, you can cause signal
distortion over long distances.
Verify the entire USB chain is
working correctly to be certain that a device that requires the ability to draw
power from the hub is not plugged into the chain on the other side of a
non-powered hub. This causes that hub and all of the devices down the chain to
be suspended. If the hub is a powered hub, verify that the power supply for
that hub is configured properly.
Out-of-date firmware or BIOS
The key to all USB devices is the firmware. The USB device's
firmware contains all of the information about the device. A port is not reset
until all of the descriptors in the firmware have been loaded and verified by
the root hub. This is critical because it applies to items such as printers and
modems. Make certain that you have the most up-to-date firmware that is
available for both your computer's BIOS and each individual device.
The symptoms of malfunctioning or incorrectly configured firmware might be
unusual. Typically, when you remove and then re-add a USB device, the device
simply becomes available again. However, the device may be displayed as a
second instance of that device, and load itself as such in Device Manager. If
you see duplicates of a device, verify that you have the most up-to-date
firmware for that device. This issue is common with USB printers and modems. A
similar issue that has the same cause occurs when a device loads a device
driver, and then adds a second device for which there seems to be no driver.
The second device is displayed with an exclamation point in a yellow circle in
Device Manager. The device may work correctly, but you cannot remove the
"ghost" device until you unplug the parent device that seems to have generated
the ghost device. Also, you may be able to resolve this issue by updating the
firmware or the device driver for that device.
Incorrectly configured root hub
USB controllers require that an IRQ be assigned. The IRQ line is
assigned in the computer's BIOS, and usually IRQ 9 is assigned.
Support WebCasts
Support WebCasts are a product support information service
offered to all Online Support customers. To view a basic WebCast on
Troubleshooting USB issues in Windows XP, visit the following Microsoft Web
site:
Remove and reinstall all USB controllers
To remove and reinstall all USB controllers, follow these steps:
- Click Start, and click Control Panel, and then click Performance and Maintenance.
- Click System, and then click the Hardware tab.
- Click the Device Manager button.
- Expand Universal Serial Bus controllers.
- Right-click every device under the Universal Serial Bus controllers node, and then click Uninstall to remove them one at a time.
- Restart the computer, and then reinstall the USB controllers.
- Plug in the removable USB storage device, and then test to make sure that the issue is resolved.