1. 3C503N.EXE Driver
2. TROUBLE.TXT File Contents

TROUBLE.TXT Driver File Contents (3C503N.EXE)

                               3Com Corporation
                EtherDisk Diskette for the EtherLink II Adapters
                                Troubleshooting



 If the EtherLink II adapter diagnostic tests fail, the adapter may not be
 defective.  Check the following:

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

 2.  Inspect all cables and connections.

 3.  If you are running the Group 2 tests, make sure that the adapter is
     securely connected to a loopback plug (coax version only) or to a 
     properly cabled inactive network.

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

 5.  Make sure that the jumper settings do not conflict with the settings of
     any other peripheral or software program installed in the computer.
     Jumper settings to check are the I/O Base Address, Interrupt Level, DMA
     channel, and Memory Base Address.  For a list of system resources
     commonly used by other peripherals, select "Additional Adapter 
     Information" from the main menu, then "System Resources" from the 
     submenu. 

 6.  Make sure that the transceiver type is correct.
   
 7.  Running tests while connected to an active network can cause intermittent
     failures.  These failures can be avoided by using an inactive network on
     which only the computer being tested (and an echo server if running the
     Group 3 tests) is connected.

 8.  If you installed an EtherLink II TP adapter, check the LEDs on the back-
     plate of the adapter.  The yellow (ACT) LED is on when there is data  
     transmission activity on the adapter.  This light will go on during
     the Group 2 and Group 3 tests.  The green (LNK) LED will be on when there
     is a correct connection between the adapter and the hub.  If the link
     pulse jumper is in the OFF position, the green LED will be on whether or
     not there is a connection.

 9.  If you installed an EtherLink II TP adapter, make sure that the settings
     for the following jumpers are correctly configured for the hub:
    
        RECEIVE THRESHOLD
        DC SIGNAL
        LINK PULSE
        EQUALIZATION
        WIRE IMPEDANCE
        TRANSMIT LEVEL
   
     For information on setting these jumpers, select "Additional Adapter 
     Information" from the main menu, then "Twisted-pair Options" from the 
     submenu.

 10. The slot in the computer may be defective.  Install the adapter in 
     another slot and run the tests again.

 11. The computer in which the adapter is installed may be defective.
     Install the adapter in a known functioning computer and run the tests
     again.

 12. The loopback plug you are using may be defective.  Try a different
     loopback plug.

 13. Replace the failed adapter with a known working EtherLink II adapter, 
     with the same jumper settings.  If the second EtherLink II adapter fails,
     something is wrong with the test environment, not with the adapter.




                   (%VER  Troubleshooting v3.4a)