P Arallel Ports Test Group; Why Run A Parallel Ports Test - Dell 4100 Installation And Troubleshooting Manual

run the subtests in the Serial/Infrared Ports Test Group to
check the 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 Serial/Infrared Ports
Test Group.
•
If the software and the diagnostics do not recognize
that you have a serial or infrared port, you should
check the
SERIAL/INFRARED PORT
System Setup program, and if necessary, run the
appropriate subtest in the Serial/Infrared Ports Test
Group.
P
arallel Ports Test Group
The subtests in the Parallel Ports Test Group check the
computer's interface with external devices, such as a
printer, that are connected to the computer through a par-
allel port. The subtests in this test group are not intended
as a diagnostic test for the actual peripheral attached to
each port. (The only exception is a printer, as described in
the Parallel Internal Test.)
NOTE: If an external loopback connector is not attached
to the parallel port, the Parallel External Loopback Test
will fail for that port and the results of this test should
therefore be ignored.
Subtests
The four subtests in the Parallel Ports Test Group and the
port functions they confirm follow:
•
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
•
•

Why Run a Parallel Ports Test?

If the diagnostics does not recognize the computer's par-
allel port, enter the System Setup program and check the
PARALLEL PORT
abled. The subtests in the Parallel Ports Test Group
category in the
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 the software, it
also may not function properly. Try operating the periph-
eral 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 the external device.
Use the documentation that came with the peripheral to
troubleshoot it and confirm that it is working 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 the
hardware. Although the following symptoms can be
caused by faulty peripherals or software errors, they
might also suggest a port problem:
•
•
Parallel External Interrupt Test
Tests the parallel port's ability to generate interrupts
from all possible sources, if an external loopback
connector or printer is available
Parallel Printer Pattern Test
Tests a printer and tests the parallel port's ability to
send a pattern to the printer, if connected
category to see if the port has been dis-
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.
Running the System Diagnostics 5-17