Black Box 34336 User Manual

7.0 Diagnostics

The troubleshooting information in this chapter applies to all Modem
applications (all dialup and leased line modes), unless specifically stated
otherwise.

For specific test procedures, turn to one of the following sections in this chapter:

• Section 7.7 — Local Modem Diagnostics

• Section 7.8 — Remote Diagnostics

If you experience communications difficulties, you should try to isolate the
defective component in your communications system. You must first identify
the symptoms and scope of the problem. Then, perform a physical inspection
of all units and connections in the system. Finally, conduct diagnostic tests.
Very often the diagnostic testing capabilities of the Modem help identify
the specific faulty component, whether it is the modem, the DTE, or the
telephone line.

To isolate the problem, carefully consider each of the following questions:

• When did the problem begin?

• What is malfunctioning? Try to isolate the component or components

of your system that are malfunctioning.

• Has there been a recent change in the system?

• Has the modem been reconfigured?

You can quickly find out if the modem is reconfigured by checking the
checksum shown in the SUMMARY screen (accessed via SETUP screen 6)
and comparing it with the checksum displayed when the modem was
operating properly. If the checksum is different from the original, one or
more option settings are changed. If you previously recorded the number
strings (i.e., option parameters) displayed in the setups screens, you can
determine which option settings are changed (by comparing the previous
and current option parameters).