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STRATA DK FAULT FINDING
SECTION 200-096-500
FEBRUARY 1991
problem. The Power Supply Test Procedure in
Paragraph 3, Section 200-096-205, Installation, can
be employed to further isolate possible causes
before removal of the KSU back cover or the power
supply unit. Figure 2 shows backplane connector
Pl and P4 and voltages at each pin. Voltages
should fall within the following ranges:
Nominal Range
-24V -26.3 - -27.8
+5v
+4.5 - +5.5
-5v -4.5 - -5.5
6.02 If voltage checks indicate a power supply
fault, replace the power supply with a correctly
operating unit. Refer to Section 200-096-200, In-
stallation, for power supply installation procedures.
TABLE B
DK24 CIRCUIT BREAKER DISTRIBUTION
TABLE D’
OK96 CIRCUITBREAKER DlSTRlBUilO'N
I
1
Circuit Backplane PCB
Breaker
bwwr)
NOTE:
+5 volts goes to all PCB slots.
-5 volts goes to all PCB slots.
Backplane PCB
( PCTUSI 1
7 STATION CABLE CONTINUITY CHECK
1 -24Vl 1 Slot 01, 02, 03
I - I
7.01 Voltmeter Test
-24V2 Slot 04, 05, 06
-
+5v All slots +5v
I -5V I
All slots
I -5v I
TABLE C
DK56 CIRCUIT BREAKER DISTRIBUTION
Circuit Breaker
-24Vl
Backplane PCB
Slots 01, 02
PCTU
I
-24V2
I
Slots 03, 04, 05
I - I
I
-24V3
I
Slots 06, 07, 08
I-I
NOTE:
+5 volts goes to all PCB slots.
-5 volts goes to all PCB slots.
6.03 The circuit breaker distribution charts show
which voltages supply the various slot locations. If
a circuit breaker pops out, this chart will help to
identify a malfunctioning PCB (reference Tables B,
C, and D).
7.02 The continuity of the cable run between the
HKSU and the electronic telephone is checked with
a voltmeter as follows:
NOTE:
Perform the following at the locations indi-
ca ted:
I. Modular block: Check all station cables.
2. MDF: Check cable from KSU to MDF.
1) Disconnect the electronic telephone.
2) Using a DC voltmeter, measure between the
wires of the two pairs to verify the readings
shown in Table E (Refer to Table G on page
27 for a PDKU).
I
3) An improper reading indicates an open,
crossed or shorted wire.
4) For the MDF-to-electronic telephone cable, a
more precise check is made using an ohm-
meter.
-3-