Dell Latitude Xpi CD - Manual (Page 85)

Running the Dell Diagnostics 4-15
• Coprocessor Error Exception Test
Verifies the math coprocessor’s ability to handle
errors and to send IRQs to the microprocessor.
• PC Card Controller Test
Checks the functionality of the PC Card controller
on the system board.
• Thermal Control Test
Checks the functionality of the thermal-monitoring
and microprocessor speed-switching device on the
system board. This test does not apply to the Dell
Latitude LM.
V
ideo Test Group
The subtests in the Video Test Group verify the proper
operation of the video controller and the video control
circuitry installed in the computer. These subtests check
for the correct operation of the readable registers in the
video circuitry and the controller. They write, read, and
verify data patterns in the cursor registers of the control-
ler. The Video Test Group also provides additional
subtests to test the color features of the color display or
an external color monitor.
Why Run a Video Test?
Many of the symptoms that would prompt you to run a
subtest in the Video Test Group are obvious, because the
display is the visual component of the computer. Before
you run the Video Test Group or any of its subtests, you
should make sure that the problem is not occurring in the
software or caused by a hardware change.
If the following symptoms still occur, run the appropriate
test(s) as follows:
• If your display or external monitor shows a partially
formed or distorted image, run all of the subtests in the
Video Test Group.
• If the alignment of text or images is off, regardless of
the program you are running, run the Text Mode
Character Test, Text Mode Pages Test, and the Graphics
Mode Test.
• If the color on the display or external monitor is
intermittent or not displayed at all, run the Text
Mode Color Test, the Color Palettes Test, and the
Solid Colors Test.
• If your display or external monitor malfunctions in
one mode but works fine in another (for example,
text is displayed correctly, but graphics are not), run
the Text Mode Character Test, Text Mode Color
Test, Text Mode Pages Test, and the Graphics Mode
Test.
Subtests
The eight subtests in the Video Test Group confirm the
following video functions:
• Video Memory Test
Checks the read/write capability of the video mem-
ory in various video modes
• Video Hardware Test
Checks the cursor registers and the horizontal and
vertical retrace bit registers in the video controller
• Text Mode Character Test
Checks the video subsystem’s ability to present data
in text modes
• Text Mode Color Test
Checks the video subsystem’s ability to present color
in text modes
• Text Mode Pages Test
Checks the video subsystem’s ability to map and
present all available video pages on the screen, one
page at a time
• Graphics Mode Test
Checks the video subsystem’s ability to present data
and color in graphics modes
• Color Palettes Test
Checks the video subsystem’s ability to display all of
the available colors
• Solid Colors Test
Checks the video subsystem’s ability to show
screens full of solid colors, and allows you to check
for missing color pixels