15JF-25F
NO PICTURE, NO SOUND
CIRCUITS TO BE CHECKED:
Tuner.
PIF.Does the noise level increase at max.
Automatic Gain Control.Contrast,Brightness and Sound controls?
5V, 32V Power Source.
Noise increase but noNo snow noise.
signal is received.
Check the tuner supply voltageDoes noise or signal appear
LB and HB must be approx. 5V, at pin40 of IC801?
BT must be approx. 32V,and NO YES
CH preset data check.
Does noise orCheck IC801
signal appear atand its related
Normalpin38 of IC801?circuit.
NO YES
Check the tunerDoes noise or
AGC at TP201.signal appear atCheck Q401
pin23 and 24Q402 and related
NormalAbnormalof IC801?circuit.
NO YES
Check pin38Check pin27Check pin1,2 of
of IC801.of IC801,TunerSF201,TunerCheck pin37 of
and related circuit.and related IC801 and
circuit.related circuit.
NO SOUND
CIRCUITS TO BE CHECKED: NO
Audio Output Circuit.Does signal appearCheck IC801 and
at pin6 of IC303? its related circuit.
YES NO
Check Speaker.Check IC303 and
peripheral circuit.
41 |
ACEC
