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Troubleshooting Guide
NO RASTER
Check +B voltage at J405
Normal 0V
Is the voltage at pin8,37 Check Open
of IC501 8V? No Fuse of AC line
Check/Replace
Check the voltage 5V,
Yes OK Fuse, D801, IC801
12V lines
Does the square 0V
waveform from pin40 of Check the voltage of
No IC501 appear? C808, C809
OK
Check/Replace Check I2C BUS lines Check/Replace
IC501 Yes (SDA, SCL) 254~380V D801
Is the waveform of Check the voltage Lower than 6V
No collector of Q451 normal? of pin9 of IC801
Check/Replace
Check/Replace
Yes D802, D805, D807,
Q451, T451, R452
Q801, IC801
Check/Replace
Is the waveform of IC803, D835, D829
No collector of Q452 normal? Check the 12V, 5V lines are
shorted.
Check/Replace
Q452 Yes
Check/Replace
T701
NO SOUND
(PICTURE OK)
(No AM Sound) (No NICAM or FM Sound)
Check whether Sound Incorrect
NO Check the Audio signal of
system of MENU OSD
pin12 of IC101 normal
is correct or not
Check/Replace Set correct Sound
Yes
IC101 system
Correct
Yes No
Check the Audio signal of Is the SIF signal of
pin55 of IC601 normal pin20 of IC101 normal?
Check/Replace
No
IC101
Yes
No
Check/Replace Are the Audio signal of
Q605, AM line pin28, 29 of IC601 normal?
Check/Replace
Yes X601, IC601, IC602
No
Are the Audio signal of
pin2, 5 of IC651 normal?
Yes Check Ro, Lo lines
No
Are the Audio signal of
pin7,11 of IC651 normal?
Check the voltage
Yes of pin10 of IC651
Check/Replace
C660, C664, Speaker
NO PICTURE/NO SOUND
(RASTER OK)
Does the Auto programme
operation?
Yes No
No NG
Is the CVBS signal of pin10 Check the voltage
fo IC101 normal? 5V, 12V, 33V of Tuner
Check/Replace
Check/Replace
Yes OK ZD182, 5V, 12V, 33V
IC101
power lines
Go to NO PICTURE Block, Check I2C BUS
NO SOUND Block lines (SDA, SCL)
OK
Check/Replace
Tuner
NO RASTER
(SOUND OK)
Check the voltage of
CPT Heater
Normal Abnormal
Abnormal Abnormal
Check the voltage of HV, Check the Heater pulse of
SCREEN of CPT pin 9 of T701
Check/Replace Check/Replace
T701 Normal Normal T701
Check/Replace Check/Replace
CPT Board Connector, FR705, FR901
NO PICTURE/NO COLOR
Is the CVBS signal of pin10 of
IC101 normal? No
Check/Replace
Yes
IC101
Is the CVBS signal of pin16 of
IC201 normal? No
Check/Replace
Yes
IC201
Is the CVBS signal of pin 3 of
IC150 normal? No
Check/Replace
Yes
Q151
Is the CVBS signal of pin 2 of
IC150 normal? No
Check/Replace
Yes
IC150
Is the CVBS signal of pin13 of
IC501 normal? No
Check/Replace
Yes
Q150
Is the Y signal of pin 27 of
IC501 normal? No
Check/Replace
Yes
IC502
Are R-Y, B-Y signal of
pin 31,32 of IC501 normal? No
Check/Replace
Yes
IC502
Are R,G,B signal of
pin19, 20, 21 of IC501 normal? No
Check/Replace
Yes
IC501
Check CPT Board
NO TELETEXT
Check the voltage
5V of C845
Abnormal Normal
Check the 5V line Abnormal
Check the voltage of C176
to be correct
Check/Replace
L154 4.8~5.2V
No Check whether video signal is
at pin3 of IC150 or not
No Check whether video signal is
at the pin16 of IC201 or not Yes
Check/Replace Yes Check I2C BUS lines
IC201 (SDA, SCL)
Check the CVBS line OK
Abnormal Check pin19, 20, 22, 23
of IC150
Check/Replace
IC150, IC151
Check/Replace
IC501