Sharp Aquos LC-37D90U, Service Manual

Page: 84 / 208

LC-37D90U
6 – 5
No video (2)
COMPONENT: No external input video
[INPUT-1]
No video at UHF/VHF broadcast signal recep-
tion
No video at digital broadcast signal reception
Is INPUT-1 selected on the input select
menu screen? Is the INPUT-SELECT for
the input signal? Is the specified TV signal selected on the input select menu screen?
YES
NO
Select INPUT-1 on the input
select menu screen for the
right input signal. Is there the analog video signal output at the
output pin (4) of tuner (TU1101)? Is there the video signal output at the output pins
(20) and (21) of tuner (TU1101)?
YES
NO
YES
NO
Does the INPUT-1 C1.PLUG
detection function? Check the tuner, IC8601 (DE-
MODULATOR) and their periph-
eral circuits (TUN_SDA/SCL,
Q8601). Check the tuner, IC8601 (DE-MOD-
ULATOR) and their peripheral cir-
cuits (TUN_SDA/SCL, Q8601).
Check the line between pin (8)
of input terminal (J501) and
pin (38) of IC501
(AV_SWITCH).
NO NO
Is there the COMPONENT video signal
input at pins (21)(Y), (23)(Pb) and (25)(Pr)
of IC501 (AV_SWITCH)? Is there the video signal output at pin (5) of
IC1103 (LEVEL_ADJ)? Are there the MPEG signal outputs
(US_TS_PKTSYNC, US_TS_EN,
US_TS_DATA, US_TS_CLK) from IC8601?
YES
NO
YES
NO
YES
NO
Check the line between the
input terminals of J501 and
IC501. Does the level adjustment con-
trol signal come from pin (6) of
IC1103 to pin (1) of IC1104? Check IC8601 and its peripheral
control circuits.
NO
Is there the COMPONENT video signal out-
put at pins (60)(Y), (59)(Pb) and (58)(Pr) of
IC501? Check IC1104 and its peripheral
circuits. Replace as required. Are there the MPEG signal inputs
(US_TS_PKTSYNC, US_TS_EN,
US_TS_DATA, US_TS_CLK) at IC8101 (CPU/
DECODER)?
YES
NO
Is there the CVBS3 signal input at pin (N3) of
IC3301 (VPC)?
YES
NO
Check IC501 and its periph-
eral circuits. Check the line between IC8601 and
IC8101.
YES
NO