Realistic STA-78 - Page 15

SYMPTOM
CAUSE,/
REMEDY
19)
No
FM
MPX
Separation
1)
lmproper adjustment
Readjust VR204
and 205.
2l
lC2O2 of
MPX
board
defective
Beplace the lC.
3)
VR204, 205
defective
Replace
the
Trimmer
Resistor(s).
4) Defective
Transistor TR2O7,2OB
or 2O9
Replace
the defective
Transistor(s).
20)
No
STEREO
light
or
FM
Stereo
does
not
work.
1)
Broken
STEREO
lndicator
Lamp
Replace
the
lamp.
2)
Defective 1C202 ol
FM
MPX
Board
Change
the defective lC.
3)
Defective Transistor f R207,208
or 209
Replace
the defective transistor(s).
4l
VR2O4,205 defective
Replace
the defective
Trimmer
Resistor(s).
21)
"LOUDNESS" has no effect. 1)
Defective "LOUDN ESS"
switch
Replace
the switch.
Defective
C501, 502 or
R501,502
Replace
the defective
part(s).
z',t
22)
"Stereo-MONO" not
effective 1)
Defective
Stereo-MONO Switch
Bepair
or
replace
the switch.
23)
"MUTING" not
effective 1)
Defective
MUTE
Switch
Repair
or replace the switch.
2)
Defective Transistor TR206
Replace
the defective
Transistor.
3)
Defective Trimmer resistor
VR203
Replace
the
Trimmer resistor.
4) Defective Diode
D207
Replace
the
Diode.
5)
Defective 1C201
Beplace
the
lC.
241
"FM
25
ltS"
not effective
1)
Defective
FM
25
pS
switch
Replace
the switch.
Defective
C4O3 or
4O4
Replace
the defective
part(s).
2l
25)
"TAPE MONlTOR"
does not operate 1)
Defective TAPE
MONITOR switch
Replace
or
repair
the switch.
26)
"BASS"
has no effect. 1)
Faulty VR504
(100
K
ohm control)
Replace it.
2)
Defective C517-520 or
R523-528
of
TONE
CONTROL
Board
Replace
the defective
part(s).
27)
"TREBLE" has
no effect 1)
Faulty
VR503
(100
K
ohm control)
Replace
it.
2)
Defective
C513-516 or
R517-522
of
TONE
CONTROL
Board
Replace
the defective
part(s).
28)
"AM/FM
SIGNAL
METER" NOt
functionlng
1)
Defective AM/FM
Signal
Meter
Replace
it.
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