Sharp LC-65D90U, Service Manual

Page: 41 / 167

41
LC-65D90U
TROUBLE SHOOTING TABLE
(Continued)
YES YES
YES YES
YES
NO
YES YES YES YES
NO NO NO NO
YES
NO NO
NO
NO NO NO
NO
YES
NO NO
YES
NO NO
YES
NO
No e
xter
nal line input <INPUT
-3>
Is INPUT
-3 selected on the input select men
u
screen? Are the signals inputted to the input ter
minals of IC3800 (A
V SWITCH)?
<Composite video signal input> Is the video signal inputted to pin (3) of IC3800? <S-video signal input> Are the
Y and C signals inputted to pins (5)
and (7), respectiv
ely
, of IC3800?
See if the video signal detection function w
o
rk
s
. Chec
k the line betw
een pin (11) of
J1106 and pin (2) of IC3800. See if the S-video signal detection function w
o
rk
s
. Chec
k the line betw
een pin (6) of
SC1105 and pin (6) of IC3800.
Select INPUT
-3 on the input select men
u
screen to ha
v
e
a desired input signal.
IIf the INPUT
-3 char
acters on the men
u
screen are g
ra
y and impossib
le to select:
Chec
k the line betw
een pin (8) of J1106
and pin (3) of IC3800. Chec
k the line betw
een pins (3 and 4) of
SC1105 and pins (5) and (7) of IC3800.
At the input of <composite video/S-video signals>
<Composite video signal input> Is the video signal outputted to pin (60) of IC3800? <S-video signal input> Are the
Y and C signals outputted to pins (60) and (59), respectiv
ely
, of IC3800?
<Composite video signal input> Is the video signal inputted to pin (1) of IC3807 (MUL
TIPLEXER)?
<S-video signal input> Are the
Y and C signals inputted to pins (1) and (5), respectiv
ely
, of IC3807 (MUL
TIPLEXER)?
No picture comes out (2)
No picture at UHF/VHF br
oadcast reception
No picture at digital br
oadcast reception
Is the video signal outputted to the output ter
minal pin (17) of tuner (TU1101)?
Chec
k or replace the tuner and its per
ipher
al
circuits
.
Is the video signal inputted to pin (7) of IC1103 (LEVEL ADJ)?
Is the le
v
el adjustment control signal f
ed
from pin (1) of IC1105 to pin (6) of IC1103?
Is the video signal inputted from the digital unit to the A
V
unit's connector (D
A_P1105)?
Chec
k the digital unit.
Is the digital video signal inputted to input ter
minal pins (90) thr
u (122) of the main
unit's connector (DM_SC2100)?
Chec
k the digital unit.
Chec
k or replace IC1105 (CONTR
OL) and
its per
ipher
al circuits
.
Is the tuner video signal inputted to pin (17) of IC3800 (A
V SWITCH)?
Chec
k IC3800 (A
V SWITCH) and its
per
ipher
al circuits
.
Chec
k the line betw
een IC3800 and IC3807.
(Q3807, Q3805, etc.)
<Composite video signal input> Is the video signal outputted to pin (20) of IC3807 (MUL
TIPLEXER)?
<S-video signal input> Are the
Y and C signals outputted to pins (20) and (18), respectiv
ely
, of IC3807 (MUL
TIPLEXER)?
<Composite video signal input> Is the video signal outputted to pin (22) of the A
V
unit's connector (PB_P5404)?
<S-video signal input> Are the
Y and C signals outputted to pins (22) and (20), respectiv
ely
, of the A
V
unit's connector (PB_P5
404)?
Mak
e sure the control signal is inputted to
pins (3) and (22) of IC3807. Chec
k the line betw
een IC3807 and P5404.
(Q3803, Q3808, Q3802, Q3809, etc.)
<Composite video signal input> Is the video signal inputted to pin (22) of the main unit's connector (PB_CN1800)? <S-video signal input> Are the
Y and C signals inputted to pins (22) and (20), respectiv
ely
, of the main unit's connector (PB_C
N1800)?
<Composite video signal input> Is the video signal inputted to pin (2) of IC402 (I.P
.F
.) via the b
uff
er Q404?
<S-video signal input> Are the
Y and C signals inputted to pins (8) and (6), respectiv
ely
, of IC402 (I.P
.F
.) via the b
uff
er Q40
4?
Chec
k the B-to-B connector "PB".
Chec
k the line betw
een connector PB and
IC402.
(Q404, Q413, etc.)
<Composite video signal input> Is the video signal inputted to pin (135) of IC400 (3D-YC & CHR
OMA) via the b
uff
er Q408?
<S-video signal input> Are the
Y and C signals inputted to pins (135) and (149) of IC400 (3D-YC & CHR
OMA) via the b
uff
ers Q408
and Q409, respectiv
ely?
Is the digital video signal outputted from the output ter
minals of IC400?
Chec
k the line betw
een pins (27) and (28) of IC402 and pin (135) of IC400.
Chec
k the
Y signal line betw
een pins (19) and (20) of IC402 and pin (135) of IC400, as w
ell as
the C signal line betw
een pin (22) of IC402 and pin (149) of IC400.
Chec
k IC400 and its per
ipher
al circuits
.