Avaya S8700 Maintenance Manual page 179

Isolating and Repairing Packet-Bus Faults
Continue with the
Troubleshooting Procedures
Packet-bus faults are usually caused by a defective circuit pack connected to the
backplane, by bent pins on the backplane, or by defective cables or terminators
that make up the packet bus. The first two faults cause shorts, while the third fault
causes either shorts or opens.
There are four procedures for correcting packet-bus faults. The one you use
depends on the nature of the fault. For example:
If the Maintenance/Test packet-bus port is activated, and if there is an
indication of open leads on the packet bus from status port-network or
Test #572, go directly to
through 3 try to locate faulty circuit packs or bent pins and these do not
cause open faults.
If there are both shorts and opens, start with
Failures, and return to Procedure 1 if shorts persist after the open leads are
fixed.
!
CAUTION:
Packet-bus fault isolation procedures involve removing circuit packs and
possibly disconnecting entire carriers. These procedures are destructive.
Whenever possible, implement these procedures during hours of minimum
system use.
To replace the following circuit packs, follow instructions in the appropriate
sections:
When the procedure asks whether the packet-bus problem has been resolved, all
of the following conditions should be met:
Every faulty lead reported by the TN771D's stand-alone mode should no
longer be reported.
Every alarm against the packet bus and the TN2312 IPSI circuit pack's
Packet Interface circuit has been resolved.
Every ISDN-BRI station and data module and every relevant ASAI- and
system port-supported adjunct is in service.
555-233-143
''Troubleshooting Procedures''
Procedure 4: Isolating
''IP-SVR (IP Server Interface)'' on page 8-959
— ''PKT-INT (Packet Interface)'' on page 8-1238
— ''TONE-BD (Tone-Clock Circuit)'' on page 8-1659
''EXP-INTF (Expansion Interface Circuit Pack)'' on page 8-762
in the next section.
Failures. Procedures 1
Procedure 4: Isolating
Issue 1 May 2002 4-105