Sharp LC-42SV32B, Service Manual

Page: 35 / 108

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