Troubleshooting; Hardware Diagnostic Utility; Dos Diagnostics Internal/External Loopback Test (Ms-Dos) - 3Com EtherLink 3C985B-SX Installation And User Manual

This chapter describes techniques for troubleshooting your NIC and correcting some types of problems. The
following topics are covered:
Instructions for performing detailed hardware diagnostics on the NIC
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Behavior of the NIC's status LEDs
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How to resolve some common networking problems
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How to reach 3Com customer service and support
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Hardware Diagnostic Utility

DOS Diagnostics Internal/External Loopback Test (MS-DOS)

An MS-DOS based diagnostic utility, TTP.EXE, is included on the CD-ROM. This utility is used for verifying that
the NIC hardware is functional. It performs internal and external loopback tests and provides resulting pass/fail
information. Perform the DOS Diagnostics tests any time you wish to rule out or identify possible NIC hardware
problems.
To use the DOS Diagnostics utility, follow this procedure:
1 Boot your system in clean MS-DOS mode rather than Novell NetWare.
NOTE: To use the DOS Diagnostics utility, you must boot your computer in clean MS-DOS mode, with no
other plug-ins, add-ons, or resident programs installed.
2 Disconnect the network cables on all NICs being tested.
The loopback tests will not perform properly if the NIC is left connected to other devices.
3 Connect a Cat. 5 UTP loopback cable to the NIC's RJ-45 jack.
A loopback cable can be constructed by connecting the following pins back to the single connector:
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Troubleshooting

Category 5 Loopback Cable
Pin 1
Pin 2
Pin 4
Pin 5
Pin 3
Pin 6
Pin 7
Pin 8
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