Toshiba 650CT Maintenance Manual page 52

2.9 Internal Modem Troubleshooting
This section describes how to determine if the computer's internal modem is functioning
properly. Perform the steps below starting with Procedure 1 and continue with the other
procedure as required.
Procedure 1:
Procedure 2:
Procedure 1 Diagnostic Test Program Execution Check
The internal modem Diagnostic Test program is stored on the computer's Diagnostics Disk.
This program checks the internal modem. Insert the Diagnostics Disk in the computer's
floppy disk drive, turn on the computer, and run the test. Refer to Chapter 3, Tests and
Diagnostics, for details.
Check 1 Execute modem test 1. If an error occurs, the I/O board may be malfunctioning.
Replace the I/O board. If errors still occur, go to Check 2.
Check 2 Execute modem test 2. If an error occurs, the DAA module may be malfunction-
ing. Replace the DAA module. If errors still occur, go to Check 3.
Check 3 Execute modem test 3. In an error occurs, the I/O board and DAA module may be
malfunctioning. Replace them both.
If any other errors occur while executing the internal modem Diagnostics Tests, go to Proce-
dure 2.
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Diagnostic Test Program Execution Check
Connector Check and Replacement Check
650CT