Realistic STA-720 - Page 13

SYMPTOM
CAUSE AND REMEDY
7.
Same
as
(6)
above but channel
operates when test signal is applied
as
in
(6).
A) Defective
PHONO
switch
52
or
TAPE
MON
switch
S7
Repair
or
replace the switch(es).
B) Defective
BALANCE
control
VR901
Replace.
C)
Resistor R910
defective
Replace the resistor.
B. Speaker
works normally but
headphone
do not work.
A)
Headphone
plug
does not mate with
jack.
Replace the
plug.
B)
Defective resistor
R651a,b
Replace the
resistor(s).
9.
All inputs work normally except
for
AUX input.
A)
Poor
contact
in
AUX
input
jack
Repair
or replace
the
jack.
B) Faulty
AUX
switch S1
Repair
or
replace
the
switch.
C)
Defective resistor R510
Replace the resistor.
10.
PHONO
input not operative
A) Defective
1C501
Replace
the lC.
B)
Faulty resistor R501, R503-R509
Replace
the faulty resistor(s).
C)
Fau lty capacitor C501
-C503
Replace the faulty capacitor(s).
D)
Poor
contact
in
PHONO
input
jack
Repair
or
replace
the
jack.
E)
Faulty
PHONO
switch 52
Repair
or
replace the
switch.
11. TAPE
MON
not operative
Defective TAPE
MON
switch 57
Repair
or
replace the switch.
Defective
contact
in TAPE
lN
jack(s)
Repair
or
replace the
jack(s).
A)
B)
12.
FM
does not operate.
A) Short circuit in
Tuner B+
circuit
Repair the short.
B)
Defective
FM(S4)
or
FM MUTE(S5)
switch
Repair or replace the switch(es).
C)
Resistor
R219, R306,
R317
or
R318 defective
Replace
the
defective resistor(s).
D)
Choke
coil
L201
defective
Replace
the
coil.
E) Capacitor
C302 defective
Replace the capacitor.
F) Defective lC
1C201
or
1C301
Replace the defective
lC(s).
G) Defective
I FT T101
Replace lFT.
13