User guide

Troubleshooting Your System 111
If the USB device functions, the USB connector on the system is likely
defective. Otherwise, the USB device is faulty and needs to be
replaced. See "Getting Help" on page 141.
2 Power down all USB peripheral devices and disconnect all USB devices
from the system except the USB mouse and keyboard.
3 Restart the system and reconnect the USB devices.
If the problem is resolved, the problem was likely caused by an overcurrent
event on one of the USB devices. If the problem persists, attempt to isolate
the faulty device by trying different USB configurations.
If the problem is not resolved, proceed to the next step.
4 Reset the system BIOS to the default settings by setting the NVRAM
_CLR jumper inside your system. Use the following procedure.
CAUTION: Many repairs may only be done by a certified service technician. You
should only perform troubleshooting and simple repairs as authorized in your
product documentation, or as directed by the online or telephone service and
support team. Damage due to servicing that is not authorized by Dell is not covered
by your warranty. Read and follow the safety instructions that came with the
product.
a
Turn off the system and attached peripherals and unplug the system
from the power source.
b Open the system. See "Opening the System" on page 47.
c Locate the NVRAM_CLR jumper on your system board (see
Figure 6-1) and set the jumper to the enabled position.
d Close the system. See "Opening the System" on page 47.
e Reconnect the system and peripherals to power and restart.
If all USB devices are operational, proceed to the next step.
If the USB devices are still not functioning, see "Getting Help" on
page 141.
f Repeat step a and step b.
g Set the NVRAM_CLR jumper to the disabled position.
h Close the system.
i Reconnect the system and peripherals to power and restart.
book.book Page 111 Wednesday, June 24, 2009 8:21 AM