Dell Latitude Xpi CD - Manual (Page 86)

4-16 Dell Latitude XPi CD Reference and Troubleshooting Guide
Many of these tests display characters or graphics on the
screen for you to verify. Samples of these screens are
shown in Appendix B, “Diagnostic Video Tests.”
NOTE: The default limit for testing SVGA modes is NO . If
you are testing an external monitor, change the default to
YES .
K
eyboard Test Group
The subtests in the Keyboard Test Group verify the cor-
rect operation of your keyboard and the keyboard
controller chip.
Why Run a Keyboard Test?
Keyboard problems are not always caused by the key-
board. For example, a complete lockup of the computer,
rendering the keyboard inoperable, is probably not caused
by a problem with the keyboard. There are two symptoms
that are likely to be keyboard-related. Sometimes, the config-
uration of a program changes the function of a key or key
combination. Similarly, key configuration programs like
ProKey can change a key’s function. Because these pro-
grams are memory resident, be sure to clear them out of the
computer’s memory before running a subtest in the Key-
board Test Group. (Clear them from memory by booting the
computer from the Dell Diagnostics Diskette.) When these
possibilities have been eliminated, and if the following
symptoms occur, you should run one or more of the subtests
in the Keyboard Test Group:
• When you press a key, the character represented by
that key appears repeatedly; the key seems to be
stuck. Run the Stuck Key Test.
• When you press a key and the response is different
from the usual response or the response you antici-
pated, the key contact may be damaged. Run the
Keyboard Interactive Test.
• When a key does not work at all, run all of the sub-
tests in the Keyboard Test Group.
Subtests
The four keyboard subtests confirm the following key-
board functions:
• Keyboard Controller Test
Confirms the ability of the keyboard controller chip
to communicate with the keyboard and confirms the
programming of the controller chip
• Keyboard Key Sequence Test
Verifies that the keys on the keyboard function cor-
rectly when you press them in a predefined order
• Keyboard Interactive Test
Checks the internal microcode of the keyboard and
the external interface of the keyboard controller chip
for a malfunctioning key
• Stuck Key Test
Checks the internal microcode of the keyboard and
the external interface of the keyboard controller chip
for a repeating key signal
M
ouse Test
The Mouse Test checks the functionality of the mouse
controller (which affects the ability to move the
trackball/mouse pointer around the screen with its
corresponding movement on your desk or pad) and the
operation of the trackball/mouse buttons.
Why Run the Mouse Test?
Touch pad or mouse problems are as likely to be caused
in RAM as they are to be caused by a faulty trackball or
mouse. Three sources of problems include the configura-
tion of a program (which changes the function of the
trackball or mouse), memory-resident programs like
Sidekick or ProKey, and failure of a device driver (the
software that controls the functions of a trackball or
mouse). If these possibilities have been eliminated and
the following symptoms persist, run the Mouse Test:
• When you press a trackball or mouse button, the
function of the button continues; the button seems to
be stuck.