3Com (R) Corporation
                          EtherDisk (R) Diskette for
                     The 3C5X9 EtherLink III NIC Family
                             Troubleshooting



 If the NIC diagnostic tests fail, the NIC might not be defective.  Check
 the following:

 1.  Make sure that the NIC is completely seated in its slot.  Review
     the installation instructions in the appropriate NIC guide.

 2.  If you are running the Group 2 test, make sure that the NIC is
     securely connected to a loopback plug or to a properly cabled network.

 3.  If you are running the Group 3 test, make sure that the NIC is
     securely connected to a properly cabled network and an echo server is
     set up on the network.

 4.  If you are configuring the I/O base address, interrupt request level,
     or boot PROM base address, make sure that the settings you choose for
     these parameters do not conflict with any other peripheral or software
     program installed in the computer.  For a list of system resources
     commonly used by other peripherals, select "Commonly used interrupt
     and I/O base addresses" from the "Configuration and Diagnostic"
     submenu.

 5.  Make sure that the configuration setting for the transceiver type is
     correct.

 6.  Running Group 2 tests while connected to an active network can cause
     intermittent failures.  These failures can be avoided by using a
     loopback plug or by connecting to an inactive network on which only
     the computer being tested is operating.

 7.  If you installed a twisted-pair NIC, check the LED on the backplate
     of the adapter.  The LED should be checked only during or after the
     diagnostic tests have been run.  The LED will be on when there is a
     proper connection between the NIC and the hub.  The LED will flash if
     the polarity of the connection is swapped.

 8.  The slot in the computer may be defective.  Install the NIC in
     another slot and run the tests again.

 9.  The computer in which the NIC is installed might be defective.
     Install the NIC in a known functioning computer and run the tests
     again.

 10. The loopback plug you are using might be defective.  Try a different
     loopback plug.

 11. Replace the failed NIC with a known working NIC, with the same
     configuration.  If the second NIC fails, something is probably wrong
     with the computer, not with the NIC.

                     (%VER  Troubleshooting v5.0a)