Dell Latitude XPi Reference Guide - Page 90

Why Run a Parallel Ports Test? If the diagnostics does not recognize the computer's parallel port, check the PARALLEL MODE system setup option to see if the port has been disabled. For instructions, see "Parallel 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 working properly. (Most printers have a self-test.) After you eliminate incorrect system configuration information 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 SCSI 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. 4-20 Dell Latitude XPi CD Reference and Troubleshooting Guide