Realistic STA-95 - Troubleshooting; Fault Diagnosis and Remedies

TROUBLESHOOTING
SYMPTOM
CAUSE AND
REMEDY
1) Receiver not operative;
pilot
lamp
does not
light.
A) Faulty
AC
power
cord
Replace
the cord.
B) Defect
in the
power
switch
Replace the
switch.
C) Broken
wire in the
power
transformer
Replace the transformer.
D) Broken
power
fuse
Replace
the
fuse.
2l
Fuse
blows
when
power
is turned
on.
A) Power
transformer
T851
defective
Replace the
transformer.
B) Short in the
primary
or
secondary of the
transformer
circuitry
Repair the
short.
C)
Damaged
rectifier
D851
Replace the rectifier.
D)
Short-circuit in
the rectifier
circuit
Repair the
short.
E)
Short
circuit in
power
transistor
TR609a, b
or
TR610a,
b
Replace
the
defective transistor(s)
and
check circuit.
3)
Pilot
lamp
does not light.
A)
Defective lamp(s)
Replace
lamp(s).
B) Disconnection
in
the
power
transformer
T851
tertiary
winding
Replace
the
transformer.
4l
Pilot
lamp lights
but no
sound from
either
channels.
A)
Resistor
R801, R804
or R809
open
Replace the
resistor(s).
B)
Capacitor
C801, C802
or C807
defective
Replace
the
defective capacitor(s).
C) Diode D851
damaged
Replace the
diode.
D)
Open in secondary
winding of the
power
transformer
T851
Replace
the transformer.
E)
Transistor
TRB03
(open),
TR804
(short),
TR805
(short)
or TR806
(open)
damaged
Replace
the damaged
transistor(s).
F) Diode
D801
(short)
damaged
Replace
the
diode.
5) A SPEAKERS
do not work.
A) Speaker
switch
SW9 defective
Replace
the switch.
6)
B SPEAKERS
do not
work.
A) Speaker
switch
SW9 defective
Replace
the switch.
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