Dell PowerEdge T100 Series Hardware Owner's Manual page 108

4 If other USB devices are connected to the system ports adjacent to those
used by the keyboard and mouse, power down the devices and disconnect
them from the system.
An overcurrent event on another USB device can cause both the keyboard
and mouse to stop functioning.
If the mouse and keyboard do not immediately return to operation after
disconnecting the other USB devices, restart your system. If the problem
persists, proceed to the next step.
If the mouse and keyboard operations are restored, reconnect the
disconnected USB devices and power them on one at a time. Note if any
device causes the same problem and replace any faulty device(s).
5 If you have remote access to your system, use a remote host to access the
system's System Setup program and enable the USB ports. If remote
access is not available, proceed to the next step.
If enabling the USB ports does not resolve the problem, see "Getting Help"
on page 141.
6 If you do not have remote access to your system, use the following
procedure to set the NVRAM_CLR jumper inside your system and restore
the BIOS to its default settings.
CAUTION:
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.
Turn off the system and attached peripherals and unplug the system
a
from the power source.
Open the system. See "Opening the System" on page 47.
b
Locate the NVRAM_CLR jumper on your system board (see
c
Figure 6-1) and set the jumper to the enabled position.
Close the system. See "Closing the System" on page 47.
d
Reconnect the system and peripherals to power and restart.
e
If the mouse and keyboard are operational, proceed to the next step.
108
Troubleshooting Your System
Many repairs may only be done by a certified service technician. You