8-1.
FAULT IN EXCHANGE
Before power supply check, confirm the following three
points to eliminate elementary faults:
1. Is
voltage
selector set correctly?
2. Is
AC
power
supplied?
3.
Is power switch O N ?
Start checking after disconnecting all wiring connected
to DC output of the power supply unit.
SYMPTON
CHECK-ITEM
Exchange does not
operate.
All DC output
voltages are
correct.
* Over-current flows into one
of plug-in units.
All or one of
DC output
voltages are
not correct.
* Fault in the power supply
unit DS-510.
Abnormal voltage
of +24V terminal.
Right range:
+24 ~ +30V
* Replace AC and DC fuses.
* Incorrect setting of the
voltage selector.
* Faulty power transformer.
Abnormal voltage
of +18V.
Right range:
+17.5 ~ +18.5V
* Faulty 2SA-753.
* Faulty µA7818KC.
Abnormal voltage
of +5V or +12V.
Right range:
+4.9 ~ +5.IV
+11.5 ~ +12.5V
* DC/DC inverter (MIV-02) is
defective.
Battery is not
charged.
Check the cur-
rent flowing
into the bat-
tery
.
Right range:
80 ~120mA
* Replace PCB of charging
circuitry.
AC & DC operation
lamps are OFF.
Buzzer does not
operate.
Note: Only when DC
power supply
(Battery) is
employed.
Check all DC
voltage.
* Replace PCB of charging
circuitry.
Blown AC and/or
DC fuse.
All DC output
voltages are
correct.
heck all sta-
tions involv-
ed in All-Call
paging.
* Over—current flows into one
of plug-in units.
(Especially on +18V)
* MIV-02 is defective.
* Replace fuse according to
the following.
Number of stations
0
~
30
31 ~ 64
65
~
Fuse
DC 5A
DC 7A
DC 10A
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