Dell Latitude Xpi CD - Manual (Page 90)

4-20 Dell Latitude XPi CD Reference and Troubleshooting Guide
Why Run a Parallel Ports Test?
If the diagnostics does not recognize the computer’s par-
allel port, check the
PARALLEL MODE system setup option
to see if the port has been disabled. For instructions, see “Par-
allel Mode” in Chapter 2. The subtests in the Parallel Ports
Test Group cannot test a port unless it is enabled.
When a port is faulty, it may not be immediately evident
that the port, and not the device connected to the port, is
faulty. Instead, the peripheral (such as a printer) might
behave erratically or not operate at all. If the external
device is not properly installed through software, it also
may not function properly. Try operating the peripheral
from different programs or through the operating system.
If it still does not work, you can eliminate the software
setup as the cause of the problem.
Another possible cause for errors is a problem with the
external device itself. Use the documentation that came with
the peripheral to troubleshoot it and confirm that it is work-
ing properly. (Most printers have a self-test.)
After you eliminate incorrect system configuration infor-
mation settings, peripheral malfunctions, and software
errors as potential causes of port problems, you can run
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 Dell Latitude Advanced Port
Replicator and the SCSI devices attached to it.
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.