Dell 4100/200, 4100/180 manual Parallel Ports Test Group, Why Run a Parallel Ports Test?

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 category in the System Setup program, and if necessary, run the appropriate subtest in the Serial/Infrared Ports Test Group.

Parallel 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

•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

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 category to see if the port has been dis- abled. 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 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:

•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