Dell Latitude Xpi CD - Manual (Page 83)

Running the Dell Diagnostics 4-13
Why Run a RAM Test?
Faulty memory can cause a variety of problems that may
not, at first glance, appear to be happening in RAM. If the
computer is displaying one or more of the following
symptoms, run both the subtests in the RAM Test Group
to verify that the memory is not at fault:
• 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.)
• The computer periodically locks up (becomes un-
usable and must be rebooted), especially at different
places and times in different programs.
Subtests
Two subtests are available for RAM: the Quick Test and
the Comprehensive Test. The Quick Test performs an
address check to determine whether the computer is
properly setting and clearing individual bits in RAM, and
whether the RAM read and write operations are affecting
more than one memory address location at a time. This
subtest checks all available RAM, including the
secondary cache. The Comprehensive Test also performs
an address check, as well as the following:
• Data pattern checks, to look for RAM bits that are
stuck high or low, short-circuited data lines, and
some data pattern problems that are internal to the
memory chips
• A parity check that verifies the ability of the memory
subsystem to detect errors
• A refresh check, to verify that the dynamic RAM
(DRAM) is being recharged properly
S
ystem Set Test Group
The subtests in the System Set Test Group check the
computer’s basic system board components and verify
their related functions.
Why Run a System Set Test?
The System Set subtests double-check many system
board components, such as the computer’s I/O circuitry, that
are tested by other test groups or subtests in the diagnostics.
You should run the System Set Test Group if you are having
Table 4-3. RAM Test Switches
Switch Description
–r number Repeats the subtest this number of times. Valid numbers are 1 through 9999. A value of 0
causes the test to run until you press <
CTRL >< BREAK >. The default value is 1.
–m number Stops the test if this number of errors occur. Valid numbers are 1 through 9999. A value of 0
causes the test to accept an unlimited number of errors. The default value is 0.
–s hexadecimal
memory address Starts the test at this hexadecimal address. Valid hexadecimal values are 0 to the highest mem-
ory address. The default value is 0.
–e hexadecimal
memory address Stops the test at this hexadecimal address. Valid hexadecimal values are 0 to the highest mem-
ory address. The default is the highest memory address.
–o[f filename,p] Outputs the test report to a file (f) or a printer (p). If you output to a file, append the filename
after the f parameter. If you do not specify a filename when using the f parameter, the test report
is output to a file named result. If you output to the printer, the test file is output to LPT1.
–[q,c] Runs the quick (q) or comprehensive (c) subtest. The comprehensive subtest is the default
value.
–np Does not pause when an error occurs or a subtest finishes. Pause (p) is the default value.