Sharp LC-42SV32B Service Manual page 35

Does not the picture come out when VHF/UHF is received?
TERMINAL UNIT:
Is TUNER_CVBS signal output from TUNER (TU101)?
MAIN_UNIT:
Is picture signal input from pin TUNER (TU101) to IC U401?
Refer to "The picture doesn't appear in all modes."
Does not the picture come out when TV is received?
TERMINAL UNIT:
Is the voltage of regulation for a TUNER circuit and the power
supply terminal of IC U401 supplied?
Is IF signal output from pin (1/2/4/5) of TUNER (TU101) to pin
(AD17/AE17) of IC U401?
MAIN_UNIT:
Do X400 (27MHz) oscillate?
Refer to "The picture doesn't appear in all modes."
Does not the picture of the component video signal input to Component go out?
TERMINAL_UNIT:
Is Component Y/Pb/Pr signal sent to pin (2)/Y, (4)/Pb, (6)/Pr of
AV1(CN111) ?
MAIN_UNIT:
Is Component Y/Pb/Pr signal sent to pin (AB13)/Y, (AB14)/Pb,
(AC14)/Pr of IC U401?
Refer to "The picture doesn't appear in all modes."
No picture on the display (2)
↓
↓
↓YES
↓YES
No picture on the display (3)
↓
↓
↓YES
↓YES
↓YES
<External input (Component)>No picture on the display (4)
↓
↓
↓YES
↓YES
NO
Check whether I2C is normally accessed between TU101 and IC
U401.
NO
Check the line between IC U401 and TU101.
NO
Each power supply circuit is checked.
NO
Check the tuner, IC U401 and their peripheral circuits. Replace
as required.
NO
Check X400 and its peripheral circuits.
NO
Check the setting of an external input device that connects of
CN111.
NO
Check the line between IC U401 and CN111
35
LC-42SV32B