ATT System 25 Installation And Maintenance Manual

Figure 4-6.
Clearing Tie Trunk Troubles (Sheet 1 of 5)
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MAINTENANCE
[6]
[7]
[8]
[9]
[10]
Figure 4-6.Clearing Tie Trunk Troubles (Sheet 2 of 5)
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MAINTENANCE
Figure 4-6.
Clearing Tie Trunk Troubles (Sheet 3 of 5)
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MAINTENANCE
Figure 4-6.Clearing Tie Trunk Troubles (Sheet 4 of 5)
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MAINTENANCE
Figure 4-6.
Clearing Tie Trunk Troubles (Sheet 5 of 5)
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MAINTENANCE
Figure 4-7.Clearing Paging Equipment Troubles 

MAINTENANCE
Clearing System-Detected Troubles
Most troubles are detected through the Alarm LED located on the Attendant
Console, the Error Log, and, in some cases, the LEDs on the circuit packs
(CPs). The following is a list of system troubles. Each item in the list is
described in this section.
Complete System Failure
Common Control Trouble
Circuit Pack Trouble
Frontplane Ribbon Connector Trouble (Release 1 Only)
Power Supply Trouble
Fan Assembly Trouble
Overheating Trouble
Backplane and CabinetTrouble...

MAINTENANCE
Failure of the CPU/Memory CP at power-up generates the following type of
error message:
FAIL: : : :
The bracketed fields contain the following information:
l is CPU/Memory
l is one of the following:
RAM TEST
ROM TEST
AA INTERFACE
DUART TEST
REAL-TIME-CLOCK TEST
BUS ERROR
WORK CYCLE
DPRTEST
MMU TEST
AA RESET STUCK : SC?
l specifies the specific location of the failure, such as the
address of a failed integrated circuit.
A representative Common Control failure message would be as follows:
FAIL:...

MAINTENANCE
After total failure, the system ceases to operate and the green LED on the
CPU/Memory CP may not flash.
Failure can also be verified by checking the LEDS on each CP.
If either a partial or total Common Control failure is detected, remove and
then restore system power.This procedure forces the system to perform a
warm restart.
If the failure exists after system restart, remove power again and reseat CP 
suspected of being faulty. (Be sure to press in all socketed devices to
ensure a firm...

MAINTENANCE
Once a faulty CP is identified, it can be replaced using the procedures in
“Reseating and Replacing Circuit Packs” under “Routine Maintenance. ”
Refer to the information in “Circuit Pack LEDs” under the “General
Maintenance Information” to understand the meaning of the CP LEDs.
.
If the Error Log notes an error related to the touch-tone receivers, the
receivers are performing below system requirements.
Touch-tone receiver problems are due to a faulty Service Circuit (ZTN85 or
ZTN131 [R3]) or...