Subtests; Scsi Devices Test Group; Why Run A Scsi Devices Test - Dell Latitude CP Reference And Troubleshooting Manual

the subtests in the Parallel Ports test group to check your
hardware. Although the following symptoms can be
caused by faulty peripherals or software errors, they
might also suggest a port problem:
•
If a peripheral works intermittently or produces
intermittent errors, the port may be faulty.
•
If the computer displays an error message that is
related to the external device connected to a port, but
corrections to the device do not resolve the error, run
the appropriate subtest in the Parallel Ports test
group.
•
If your software and the diagnostics do not recognize
that you have a parallel port, you should check the
Parallel Mode system setup option, and if necessary,
run the appropriate subtest in the Parallel Ports test
group.

Subtests

The four subtests in the Parallel Ports test group confirm
the following port functions:
•
Parallel Internal Test
Checks several internal functions of the parallel port
•
Parallel External Loopback Test
Tests the functionality of the control lines through an
external loopback connector, if an external loopback
connector is available
•
Parallel External Interrupt Test
Tests the parallel port's ability to generate interrupts
from all possible sources, if an external loopback
connector is available
•
Parallel Printer Pattern Test
Tests whether the port(s) can retain data, print text
on a printer, and generate interrupts
S
CSI Devices Test Group
The subtests in the SCSI Devices test group check the
functionality of the small computer system interface
(SCSI) controller in the C/Port APR or C/Dock Expan-
sion Station, and the SCSI devices attached to either.
These tests run only if the computer is docked.
4-20 Dell Latitude CP Reference and Troubleshooting Guide
NOTES: Before conducting these subtests on an external
SCSI CD-ROM drive, insert into the drive a CD with
audio and data tracks (such as a multimedia CD). The
Audio Output Test requires a CD with audio tracks; all
other subtests require a CD with data tracks.
If the external CD-ROM drive is empty, or if it contains a
CD that does not have the required data or audio tracks,
the subtest fails.

Why Run a SCSI Devices Test?

If you check your SCSI hard-disk drive to determine the
amount of available space, your operating system will
probably report problem areas. Problem areas on hard-
disk drives are common, because most hard-disk drives
have a small amount of space that is not usable. The
hard-disk drive keeps a record of this space so that your
computer will not attempt to use it. Identification of
unusable disk space, unless it is an unusually large
amount (over five percent of the possible total), should
not be regarded as a cause for testing the hard-disk drive.
These are the most common symptoms that might prompt
you to test a SCSI device:
•
A SCSI hard-disk drive fails during the boot routine.
•
Seek errors are reported by the operating system or
application programs.
•
An error message appears on the screen stating that
the computer cannot read from or write to a SCSI
device.
•
Data on a SCSI device is corrupted or lost; these
problems may be intermittent. Once saved by a pro-
gram, files cannot be properly recalled.
Subtests
The seven subtests in the SCSI Devices test group con-
firm the following drive functions:
•
Internal Diagnostic Test
Causes the device to run its internal self-test.
•
Seek Test
Checks the device's ability to search for a specified
track on the device and to position its read/write
heads to all tracks.