Chapter 9 - Fault Finding; Fault Classification; Fault Clearing Procedures - Toshiba Strata DK40 Installation & Maintenance Manual

Fault Finding
This chapter describes the procedures to diagnose faults in the Strata DK40 Key Service Unit
(KSU). Faults are classified and then cleared by replacing the malfunctioning unit and by
performing operational tests in the sequences by prescribed by the fault clearing flowcharts in
"Fault Isolation Flowcharts" on Page

Fault Classification

A Fault Classification Flowchart is provided to ensure that fault clearing is pursued in a
logical sequence
The flowcharts assume that the fault was discovered and reported by a digital or electronic
telephone user. All faults, therefore, are classified according to the way they would appear at
the digital or electronic telephone.

Fault Clearing Procedures

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.
Important!
Initialise the system (Programs 91-9 and 03) before testing new systems or when changing
the DK40 KSU.
Faults in the Strata DK40 are cleared by replacing PCBs, telephones (digital or electronic) or
the power supply, as instructed in the flowcharts
Strata DK40 I&M Spring 1999
Refer to the Strata DK40 Programming Manual or DK Library CD-Rom for more details.
(Flowchart 9-1).
Many system features are assigned, enabled or disabled using software entries
as described in the Strata DK40 Programming Manual. It is very important to
verify that the system programming is correct and functional before
troubleshooting the hardware.
9-8.
9
9-1