Chapter 9. Lic And Line Problems (Lss) - IBM 3745 Problem Determination Manual

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Problems on One Line Only (LIC1 to LlC4)
DTR is OFF
• Activate the line (host side).
• Check the DTE-to-DCE cable connection.
• Perform a tarlgate wrap test (see Chapter 16). Then return here to analyze the results.
Tailgate Wrap Test Results - - - - - - - - - - - - - - - - - - - - - - - - - - - - ,
• Test not successful: Replace the LlC. Follow the procedure "Problems on All Lines of a LlC"
frolT! step 7 on page 9-5.
• Test successful: Check with the network operator the compatibility of line parameters at both
ends of the line.
If they are correct, suspect the host software, otherwise, go to step 11 on page 9-11.
DTR
is ON and
DSR
is OFF
• Check that the modems are ready and operational.
• Check that the cables are correctly plugged in.
• Perform a tailgate wrap test (see Chapter 16). Then return here to analyze the results.
Tailgate Wrap Test Results --------------------"~----------,
• Test not
su~cessful:
Replace the L1C. Follow the procedure "Problems on All Lines of a L1C"
from step 7 on page 9-5.
• Test successful, check:
Modem (modem tests are listed on page 9-30)
If the problem is not fixed, go to step 11 on page 9-11.
DTR
and
DSR
are ON:
Perform a tailgate wrap test (see Chapter 16). Then return here to
analyze the results.
Tailgate Wrap Test Results - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ,
• Test not successful: Replace the LlC. Follow the procedure "Problems on All Lines of a L1C"
from step 7 on page 9-5.
• Test successful: Perform a data wrap test at the 3745 modem level (see Modem and Link Tests
on page 9-30 and Chapter 16). Then return below to analyze the re$ults.
Modem Data Wrap Test Results - - - - - - - - - - - - - - - - - - - - - - - - - : : - - - ,
• Test not successful: Suspect the modem or the cable.
• Test successful, check:
The remote control unit. Perform appropriate remote control unit tests.
The line parameters with the network operator.
The network.
If the proble.m is not
~xed,
go to step 11 on page 9-11.
Chapter 9. lIC and Line Problems (LSS)
9-13