Service manual

28
14GT15
14GT20
TROUBLE SHOOTING TABLE (Continued)
NO PICTURE, NO SOUND
Does noise signal appear at
pin (44) of IC801 ?
NO SOUND
No snow noise.
Does noise or signal appear at pin (40)
of IC801 ?
Noise increases but no signal is
received.
Check the tuner supply voltage LB must
be approx. 5V. BT must be approx, 32V.
And CH preset data check.
Check the tuner AGC at
TP201.
Does noise or
signal appear at
pin (38) of IC801 ?
Check IC801 and
its related circuit.
Check Q205 and
related circuit.
Check pin (1) of SF201 and Tuner related
circuit.
Check pin (37)of IC801 and related
circuit.
CheckIC801.
Check C356 and
peripheral circuit.
Check pin (27) of
IC801, Tuner and
related circuit.
Check pin(38) of
IC801.
Does the noise level increase at max.
Contrast, Brightness and Sound controls ?
CIRCUITS TO BE CHECKED:
» Tuner.
» PIF.
» Automatic Gain Control.
» (5V), (32V) Power Source.
CIRCUITS TO BE CHECKED:
» Sound system pins (28) and
(44) of IC801.
» Sound Detector Circuit.
» Sound Switch and Att.
Control.
» Audio Output Circuit.
Does signal appear at pins
(6) and (8) of IC301 ?
Check P302 or P301
connector of IC301 and
peripheral circuit.
Check Q301, pins(4) and (6)
of IC801 and peripheral
circuit.
Does signal appear at pin(28)
of IC801?