Toshiba STRATA DK24 Manual page 577

1 GENERAL IMPORTANT!
1 .Ol This section describes the maintenance pro-
cedures used to diagnose faults in the STRATA DK
digital key telephone system. Faults are classified
and then cleared by replacing the malfunctioning
unit and performing operational tests in the se-
quences prescribed by the fault clearing flowcharts
in Paragraph 5.
Many system features are assigned, en-
abled or disabled using software entries
as described in
Programming Procedures.
It is important to verify that the system
programming is correct and functional
before troubleshooting the hardware.
2 FAULT CLASSIFICATION
2.01 A Fault Classification Flowchart is provided to
ensure that fault clearing is pursued in a logical
sequence (Chart No. 1).
3.02 In newsystems, or when the PCTU or PCTUSI
PCB has been changed, the initialization proce-
dure must be performed before testing. The system
data stored on the original PCTU or PCTUSI will be
protected from loss by the backup battery on that
PCB. Therefore, the initialization sequence should
nof be performed if the original PCB is reinstalled.
NOTE:
2.02 An assumption is made in the flowcharts that
the fault was discovered and reported by an elec-
tronic telephone user. All faults, therefore, are
classified according to the way they would appear
at the electronic telephone.
2.03 Faults and associated flowcharts in Table A
are organized into the following categories:
In this section all information relating to the
PCTU PCB applies to the PCTlJSl, PCTUl,
PCTU2, and PCTU3 unless otherwise stated.
1
3.03 Faults in the system are cleared by replacing
PCBs, electronic telephones or the power supply,
as instructed in the flowcharts.
TABLE A
FLOWCHARTS
3.04 Five symbols are used in the flowcharts,
which are identified in Figure 1.
Start and end of a
flowchart sequence.
Flowchart Title
1
Fault Classification
2 Power Faults
3 Station Faults
4 KSU Faults
5
CO Line Faults
6 Intercom Faults
7 DSS Console Faults
8 Speed Dial Faults
9
MOH, BGM, Page & Relay Faults
10
SMDR Faults
11
PSTU Faults
12 Door Phone Faults
13 TIE Line Faults
14 Remote Maintenance/TTY Faults
3 FAULT CLEARING PROCEDURES
3.01 Before attempting to clear any fault, ensure
that it is in the system and not caused by associated
external equipment, such as wiring, MOH source,
etc.
STRATA DK FAULT FINDING
SECTION 200-096-500
FEBRUARY 1991
Important notes
affecting the fault
clearing procedure. -----I-.-
Question to be answered
YES or NO.
Progression TO or FROM
another flowchart location.
Letters and numbers denote
the exact entrance or exit
points.
Statement of a
required action.
I
c
FIGURE l-FLOWCHART SYMBOLS