ATT System 25 Installation And Maintenance Manual

MAINTENANCE
Memory (ZTN81 [RIV7] or ZTN127 [RI V2]J: The red LED on this CP lights
when power is applied and goes dark upon successful completion of the
ROM checksum test initiated by the Call Processor CP. Failure is indicated
by a steadily lighted red LED.
Call Processor [ZTN82 (R1V1) or ZTN128 (R1V2)]: The green LED on this
CP lights when power is applied and flashes during normal operation. When
the system resets itself, the green LED lights and then goes dark for a few
seconds while the Call...

MAINTENANCE
Attendant Console LED
A lighted green Alarm LED on the console indicates the presence of a
 Permanent System Alarm. The LED flashes with each new alarm. The attendant
can press the associated button to cause the LED to light steadily. A lighted red
Alarm LED indicates a barrier code violation.
Power Supply LED
A lighted green LED on the power supply indicates normal power operation.
Switches and Test Points
The power switch on the back of the cabinet controls cabinet ac power and
should be...

MAINTENANCE
Using RIMS, the remote administrator can initialize translations after the
switch itself is installed. As long as there is no hardware change, the remote
administrator can do ongoing administration without having to visit the
customer’s site. Similarly, to trouble-shoot a problem, a technician can call
the RIMS port and check the Error Log to determine the cause of the trouble.
The technician can clear alarms remotely and decide whether or not a service
dispatch is necessary.
The remote...

MAINTENANCE
Administration Requirements
For a RIMS call to be made during initialization, at least one voice station and
one trunk must be translated. A cold start with defaults provides these
translations.
The RIMS transfer code (*1 00) can be assigned to a Repertory Dialing feature
button on a multiline voice terminal. If the Remote Access feature is used,
the trunk used for RIMS access must be administered as a remote access
trunk.
Hardware Requirements
Customer’s Site:
None.
.
Remote Location:
A dumb...

MAINTENANCE
MAINTENANCE STRATEGY
Fault isolation is the cornerstone of the System 25 maintenance strategy.
Maintenance activity isolates faults to one (or more) repairable or replaceable
maintenance units. Equipment should be tested in the following order:
1.
2.
3.
4.
5.
6.
Terminal equipment
Station wiring
Port circuit packs (CPs)
Common control circuitry
Power supply and cabinet
Backplane.
The first fault isolation step attempts to reproduce the fault, whether it is
system-detected or user-reported.A...

MAINTENANCE
SYSTEM
TROUBLE
REPORTEDUSER-REPORTEDDISCUSS THE TROUBLEWITH SYSTEM USERS
CAP ALARM
REPORTED
CAP ALARMED
READ PERMANENT
SYSTEM ALARMS
TABLE IN ERROR
LOG:
AND CHECK
CIRCUIT BOARDS
AND POWER LED
STATUSSYSTEM OR CANNOT
ACCESS ERROR LOG
DEFECTIVE
POWER
SUPPLY
CHECK POWER
LED AND FANS
READ (1) PERMANENT SYSTEM
ALARMS, (2) TRANSIENT
SYSTEM ERRORS TABLE,
AND/OR (3) MOST RECENT
SYSTEM ERRORS IN TABLE
ERROR LOG ;
AND CHECK CIRCUIT
BOARDS AND POWER SUPPLY
LED STATUS CPU/MEMORY
CIRCUIT FRONTPLANE/...

MAINTENANCE
Sometimes, faults recorded in the error log and user-reported troubles will
exist at the same time. The logged faults should always be cleared first, if
possible. This procedure often clears the user-reported troubles without any
additional maintenance.
Clearing the most serious logged fault may clear some or all of the other
faults. Descriptions of the errors in the error log section indicate their relative
urgency.
Error log records should be manually recorded before clearing a recorded...

MAINTENANCE
Common Control Problems
Common Control circuitry is difficult to troubleshoot. The system must be
powered down before any of these CPs are replaced. Before powering the
system down, save translations to tape (see“Using the Digital Tape Unit”).
Other repair procedures may also require the system to be powered down.
After removing a suspected faulty CP, do the following:
l Visually inspect the CP.If a problem is identified, attach a note to
the CP identifying the problem.
l Attach any error...

MAINTENANCE
Station, Wiring, and Trunk Problems
If the system indicates that a fault is with a station, or if a user complaint
indicates a station problem, the trouble must be isolated to the station itself
or to the wiring between the cabinet or station interconnect panel and the
station.
The station wiring, particularly the mounting cord, should be visually
inspected in cases of station trouble reports. A dead station could be caused
by a loose mounting cord.Station trouble can also occur when wiring...

MAINTENANCE
USING THEDIGITAL TAPE UNIT
The Model DC4 Digital Tape Unit (DTU) or equivalent is extremely important
in system maintenance. System Translations are stored in the DTU and can
be accessed in the unlikely event that translations are lost during a system
failure.
This section covers the following:
l Setting Up the DTU
l Saving Translations
l Verifying Translations
lRestoring Translations.
Setting Up the DTU
The DTU must be properly connected to the system before it can be used.
Refer to Section...