User manual
DEFINITY Enterprise Communications Server Release 6
Maintenance for R6vs/si 
555-230-127  
Issue 1
August 1997
Maintenance Object Repair Procedures 
Page 10-1404TONE-BD (Tone-Clock Circuit Pack) 
10
NOTE:
Replacing the circuit pack and retesting it with the test 
tone-clock command is not adequate to retire this alarm and 
return the Tone-Clock Circuit Pack to full service; the Clock 
Health Inquiry test (#46) will continue to fail. Because the 
ability to generate clocks was considered lost, once any 
repairs have been made it is necessary to execute the set 
tone-clock PC override command, forcing the circuit pack to 
become active. If the problem has not actually been 
corrected, this action may cause a disruption in service for 
active digital facilities users.
3. If error 2305 or 3848 persists, all clock signals from the indicated 
board were lost. If the reported Tone-Clock circuit pack is in a Port 
Network with duplicated Tone-Clocks, the problem may lie with the 
circuit pack responsible for selecting the active Tone-Clock circuit 
pack (the 
t/c selector
).
■ For a PPN, the t/c selector is the DUPINT circuit pack on 
carrier A.
■ For an EPN, the t/c selector is the active EXP-INTF circuit 
pack that is connected to the PPN. This is EXP-INTF 2A01 or 
2B02 for EPN1 and 3A01 or 3B02 for EPN2.
The t/c selector circuit pack of interest is the one which was active 
at the time the error was logged. This is the currently active t/c 
selector unless there has been an SPE interchange for PPN 
problem, or an EXP-INTF link switch for EPN problem, In order to 
determine whether an interchange has occurred since the 
TONE-BD error, examine the display initcauses log for SPE 
interchanges, and EXP-LNK entries in the hardware error log for 
expansion link interchanges.
If the t/c selector circuit pack was not replaced as part of the 
previous step, replace it now. Follow procedures described in 
‘‘
Replacing Defective SPE Circuit Packs’’ in Chapter 6, ‘‘Reliability 
Systems: A Maintenance Aid’’ for the DUPINT circuit pack, or in the 
EXP-INTF section of this chapter for the Expansion Interface.
4. If the error has not been corrected at this point, there is a problem 
with the TDM Bus within the Port Network containing the reported 
Tone-Clock circuit pack. This may include TDM Bus intercarrier 
cables, Bus terminators, bent pins on the backplane, and errors on 
any circuit pack plugged into the same Port Network. Refer to the 
TDM-BUS section.
5. If the problem persists, follow normal escalation procedures.
l. Error Type 2561
This error indicates that a Tone-Clock circuit pack, with 
a different circuit pack code as required for this system, has been inserted 
in the port slot as shown in the Hardware Error Log. To resolve this error, 
refer to the ‘‘
How to Replace a Tone-Clock Circuit Pack’’ section for an 










