Dell Latitude Xpi CD - Manual (Page 84)

4-14 Dell Latitude XPi CD Reference and Troubleshooting Guide
a problem and cannot isolate the failure or malfunction to a
particular system board component.
The System Set Test Group also verifies the proper oper-
ation of other computer components, such as the speaker,
that are not tested elsewhere in the diagnostics.
The following symptoms usually suggest a problem with
a component or subassembly that warrants running a Sys-
tem Set subtest:
• A program is not running as usual, or a proven piece
of software appears to malfunction and you confirm
that the software itself is not at fault. (You can con-
firm that the software is functioning properly by
moving it to another computer and running it there.)
• A PC Card you previously accessed can no longer be
accessed.
• The computer periodically locks up, especially at
different places and times in different programs.
• Parity errors or page fault failures (any error mes-
sage that contains the word parity or page fault) occur
at any time during operation. These errors are usually
accompanied by a reference to an address, which you
should record on a copy of the Diagnostics Checklist
found in Chapter 5.
• Correcting errors in the system configuration infor-
mation does not resolve a problem.
• The computer’s clock/calendar stops.
• The speaker no longer functions. The problem could
be a failure of the system timers as well as a failure
of the speaker itself. Run the System Timers Test,
followed by the System Speaker Test.
• If a peripheral device appears to malfunction, run the
Interrupt Controllers Test. If the computer fails the
test, the problem lies with the interrupt controller; if
the computer passes, then the problem lies with the
peripheral device.
• A spreadsheet program or other type of mathemati-
cal application runs abnormally slow, generates error
messages concerning calculations or operations, runs
incorrectly, or generates incorrect results; or a
proven piece of the program appears to malfunction
and you confirm that the software itself is not at
fault. (You can confirm that the software is not at
fault by moving the program to another computer
and running it there.)
• The computer halts in the middle of performing cal-
culations or complex mathematical operations.
Subtests
The subtests in the System Set Test Group confirm the folow-
ing computer functions:
• CMOS Confidence Test
Checks the nonvolatile RAM (NVRAM) for accessi-
bility and reliability of data storage by performing a
data pattern check and verifying the uniqueness of
memory addresses.
• DMA Controller Test
Tests the direct memory access (DMA) controller
and verifies the correct operation of its page and
channel registers by writing patterns to the registers.
• Real-Time Clock Test
Confirms the functionality and accuracy of the com-
puter’s real-time clock (RTC).
• System Speaker Test
Checks the functionality of the speaker by generat-
ing eight tones.
• System Timers Test
Checks the timers used by the microprocessor for
event counting, frequency generation, and other
functions. Only the functions that can be activated
by software are tested.
• Interrupt Controller Test
Generates an interrupt on each interrupt request
(IRQ) line to verify that devices using that line can
communicate with the microprocessor and that the
interrupt controller sends the correct memory
addresses to the microprocessor.
• Coprocessor Calculation Test
Checks the use of different types of numbers and the
math coprocessor’s ability to calculate correctly.
• Coprocessor Duty Cycle Test
Tests the math coprocessor’s ability to perform com-
plex mathematical operations.