Toshiba Strata DK 16 Installation And Maintenance Manual page 240

FAULT FINDING
SECTION 100-816-500
MARCH 1993
START
1. Check CO line wiring
per section 100-816-008.
2. Test central office line
using a standard telephone
or butt set at the
TELCO block.
Repair as necessary.
4-1
CHART NO. 4
CO LINE DIAL TONE FAULTS
Is the fault YES
cleared?
YES
NO
4-2
Are all
faulty CO lines
on a replaceable PCB
(not including KSU
Main PCB )?
NO
4-7
Are the
YES
faulty CO lines
only in the DK16
expansion
unit?
NO
4-10
Change the DK8 or
DK16 Base KSU and
initialize the system
(Prog: 90, 92, 03).
NOTE:
Retest.
Program 03 is not used on DK8.
Is the
NO
fault
cleared?
YES
Go to
4-5
-10-
END
Change the PCB
4-3
and retest.
4-4
Is the
NO
fault
cleared?
YES
4-5
Replace the defective
unit and return it to the
repair center.
END
Change the expansion
4-9
unit and retest.
4-6
Is the
fault
cleared?
Call your technical
support group.
Replaceable CO Line
PCBs
DK8: QCDU
DK16 Base: KCOU
DK16 Expansion:
KCDU, PCOU
YES
Go to
4-5