DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126
Issue 4
June 1999
Alarms, Errors, and Troubleshooting
5-107Packet Bus Fault Isolation and Repair
5
8. Repeat this procedure for the other SPE or Tone/Clock. If both have
already been checked, go to the next step.
9. If all SPE and/or EPN control circuit packs have been checked and the
problem is not resolved, continue with Procedure 4.
Procedure 4
Procedure 4 is used when the preceding procedures fail or when open leads are
present. It is helpful in identifying multiple circuit pack faults and carrier hardware
faults. It attempts to isolate the failure to a particular set of carriers and checks
only the circuit packs in those carriers.
In Procedure 4, the TDM/LAN Cable Assemblies and TDM/LAN termination
resistor packs are replaced. If this action does not resolve the packet bus fault,
the carriers are reconfigured by moving the termination resistor packs on the
carrier backplanes in such a manner that certain carriers are disconnected from
the bus. To terminate the packet bus at the end of a particular carrier, unplug the
cable that connects the carrier to the next carrier and replace the cable with a
TDM/LAN terminator resistor pack (see Figure 5-47
). When the length of the
packet bus is modified with this procedure, circuit packs that are essential to
system operation (and the TN771D Maintenance/Test in standalone mode) must
still be connected to the new ‘shortened’ packet and TDM busses.
!
DANGER:
Power must be removed from the entire port network before any cables or
terminators are removed. Failure to do so can cause damage to circuit
packs and power supplies, and can be hazardous to the technician.
!
DANGER:
Circuit packs in carriers that are not part of the shortened bus are not
inserted. As a result, these circuit packs are not alarmed Ignore alarm
status for these circuit packs for now All alarms should be resolved when
the cabinet is restored to its original configuration.
