20GT-15
NO
YESCheck IC801.
Check Q205 and Q203 related circuit.
Check IC801 and related circuit.
YES
IC801?
YES
No snow noise.Does signal appear at pin (28) & pin (29) of IC801?Check C356, C359 and peripheral circuit.Check Q301, pins (4) and (6) of IC801, and peripheral circuit.
Does signal appear at pin (40) of
(Continued)NO
NO
Check IC PIF circuit and itOs related circuit.
Does signal appear at pin (38) of IC801?
NO
NO
NO SOUNDYES (Signal)YES
Does the noise level increase at max. Contrast, Brightness and Sound controls?
NO PICTURE, NO SOUND
Does signal appear at pin (44) of IC801?Does signal appear at pin (6) and (8) of IC301?Check connector IC301 and peripheral circuit.
Check pin (27) of IC801, Tuner and realted circuit.
Normal
.
TROUBLE SHOOTING TABLE Check the tuner AGC at TP201
NormalAbnormal
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 pin (38) of IC801.
Tuner PIF Automatic Gain Control. (5V), (32V) Power Source. Sound system pins (28), (29) & Sound Detector Circuit. Sound Switch and Att. Control. Audio Output Circuit.
CIRCUITS TO BE CHECKED: EEEECIRCUITS TO BE CHECKED: E (44) of IC801. EEE
NO
Normalcircuit.
Blown out.
ON/OFFON
Replace the fuse.
Check IC701, D701 and C707.Checking the protector
D1001 (Power LED Green) turns on.D1001 (Power LED Red) turns on or turns ON/OFF.
The fuse is blown out again.
YES
Check IC801.
Abnormal
NO
NormalNormaloscillate?IC801.
Check F701.
NO RASTERDoes horizontal circuit Check CRT connector K1-K5 bias.Check IC605, IC751 and
Check Secondary Main+B (Approx. 115V)
Check T701 pin (7) voltage (Approx. 310V at 220V AC)
TROUBLE SHOOTING TABLE
IC753.Normal
AbnormalAbnormal
Check D758, IC702 and Check R618 and R615.
Check R701, R707 and D709.
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