14Gt15 - Sharp 14GT15 Service Manual

14GT15

14GT20
TROUBLE SHOOTING TABLE
CIRCUITS TO BE CHECKED:
» Tuner.
» PIF.
» Automatic Gain Control.
» (5V), (32V) Power Source.
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.
Check pin(38) of
IC801.
CIRCUITS TO BE CHECKED:
» Sound system pins (28) and
(44) of IC801.
» Sound Detector Circuit.
» Sound Switch and Att.
Control.
» Audio Output Circuit.
NO PICTURE, NO SOUND
Does the noise level increase at max.
Contrast, Brightness and Sound controls ?
Check pin (27) of
IC801, Tuner and
related circuit.
NO SOUND
Does noise signal appear at
pin (44) of IC801 ?
Does signal appear at pins
(6) and (8) of IC301 ?
Check P302 or P301
connector of IC301 and
peripheral circuit.
(Continued)
Does noise or signal appear at pin (40)
of IC801 ?
Does noise or
signal appear at
pin (38) of IC801 ?
Check pin (1) of SF201 and Tuner related
circuit.
Check pin (37)of IC801 and related
circuit.
Does signal appear at pin(28)
of IC801?
Check C356 and
peripheral circuit.
28
No snow noise.
Check IC801 and
its related circuit.
Check Q205 and
related circuit.
CheckIC801.
Check Q301, pins(4) and (6)
of IC801 and peripheral
circuit.