13
25WG3
TR
OUBLESHOO
TING
Figure 1
If bus error happen, the LED RED (pin (30) of IC1001 low) indicator starts flashing and the power is turned off.
The power key is still effective.
E PROM (S24C04A)
IC1002
1 chip IC (TDA8375)
IC201
Sound processor IC (TDA7429S)
IC302
PSI IC (TDA4671)
IC401
PLL (ST6HD64)
TU201
2
Check F750.
Blown out.
Replace the fuse.
The fuse is again
blown out.
Check T701 pin(1)
voltage (approx. 310V
at 220VAC).
Check D704, and
IC701, C730, C731.
Check R701, R703 and
D703.
Check D708 and D714.
Check IC703.
Check secondary main + B
(approx. 120V).
D1101 (power LED
green) turn ON ?
Check CRT connector
K1-K5 bias.
Check IC851
and peripheral
parts.
Check (K) wire
and plug.
Horizontal circuit oscillate?
Check IC201,
Q603, IC202
and Q601.
D1101 (power LED red)
turns on or turns
ON/OFF ?
Check the protector
circuit.
Bus error mode.
See
Figure 1
.
NO RASTER
Normal
Normal
Normal
Normal
Normal
Abnormal
Abnormal
Abnormal
YES
YES
NO
NO
ON/OFF
Does the snow noise appear on
the picture tube at max contrast
and brightness control?
Snow noise increase.
Check the TUNER 33V.
Check IC203,
R227.
Check the tuner AGC.
Check IC201.
Check the
tuner circuit.
NO PICTURE
B
Normal
Normal
Abnormal
Abnormal
No snow noise.
Check the voltage of
S-convertor (12V).
Check IC301, Q202, Q204
and its related parts.
Check IC201 and
peripheral circuit.
Check R318, C303.
Does noise or signal appear at pin (27) of IC201?
Does noise or signal appear at pins (29), (30)
of IC302?
Does noise or signal appear at pins (2), (5)
of IC3301?
Check (FS) connector, IC3301 and their
peripheral circuit.
Check IC302 and peripheral circuit.
Does noise or signal appear at
pin (16) of IC201?
Check PIF circuit and
its related parts.
Does noise or signal
appear at pin (24) of
IC201?
B
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
Normal
Abnormal
NO SOUND
Check IC201, IC301, IC302 and peripheral circuit.
Check IC706, C355, IC302 and peripheral circuit.
Check IC201, C603, C604, C609 and R605.
NEITHER VERTICAL NOR
HORIZONTAL SYNCHRONIZATION
Summary of Contents for 25WG3
Page 16: ...16 25WG3 A B C D E F G H 1 2 3 4 5 6 7 BLOCK DIAGRAM MAIN 1 UNIT BLOCK DIAGRAM ...
Page 17: ...17 25WG3 7 8 9 10 11 12 13 ...
Page 18: ...18 25WG3 A B C D E F G H 1 2 3 4 5 6 7 MAIN 2 UNIT BLOCK DIAGRAM ...
Page 19: ...19 25WG3 7 8 9 10 11 12 13 ...
Page 20: ...20 25WG3 A B C D E F G H 1 2 3 4 5 6 7 CRT FRONT S OUT UNIT BLOCK DIAGRAM ...
Page 21: ...21 25WG3 7 8 9 10 11 12 13 ...
Page 22: ...22 25WG3 A B C D E F G H 1 2 3 4 5 6 7 CHASSIS LAYOUT ...
Page 23: ...23 25WG3 7 8 9 10 11 12 13 ...
Page 24: ...24 25WG3 A B C D E F G H 1 2 3 4 5 6 7 SCHEMATIC DIAGRAM MAIN 1 UNIT SCHEMATIC DIAGRAM ...
Page 25: ...25 25WG3 7 8 9 10 11 12 13 ...
Page 26: ...26 25WG3 A B C D E F G H 1 2 3 4 5 6 7 MAIN 2 UNIT SCHEMATIC DIAGRAM ...
Page 27: ...27 25WG3 7 8 9 10 11 12 13 ...
Page 29: ...29 25WG3 7 8 9 10 11 12 13 7 8 9 10 11 12 ...
Page 31: ...31 25WG3 7 8 9 10 11 12 13 M E M O ...
Page 32: ...32 25WG3 A B C D E F G H 1 2 3 4 5 6 7 PRINTED WIRING BOARD ASSEMBLIES MAIN 1 UNIT ...
Page 33: ...33 25WG3 7 8 9 10 11 12 13 ...
Page 35: ...35 25WG3 7 8 9 10 11 12 13 FRONT UNIT 7 8 9 10 11 12 S OUT UNIT ...
Page 36: ...Ref No Part No Description Code Ref No Part No Description Code 25WG3 36 M E M O ...
