Sharp LC-65D90U, Service Manual

Page: 40 / 167

40
LC-65D90U
TROUBLE SHOOTING TABLE
(Continued)
YES YES
NO NO
YES YES
NO
YES YES YES YES
NO NO NO NO
YES
NO NO
YES
NO NO
YES
NO
No e
xter
nal line input <INPUT
-1>
Is INPUT
-1 selected on the input select
men
u screen?
Is the video signal inputted to pin (65) of IC3800 (A
V SWITCH)?
Chec
k the line betw
een pin (8) of J1101 and
pin (65) of IC3800.
See if the video signal detection function w
o
rk
s
. Chec
k the line betw
een pin (11) of
J1101 and pin (70) of IC3800. Select INPUT
-1 on the input select men
u
screen to ha
v
e
a desired input signal.
If the INPUT
-1 char
acters on the men
u
screen are g
ra
y and impossib
le to select:
At the input of <composite video signal>
Is the video signal outputted to pin (60) of IC3800? Is the video signal inputted to pin (1) of IC3807 (MUL
TIPLEXER)?
No picture comes out (1)
No e
xter
nal line input <INPUT
-2>
Is INPUT
-2 selected on the input select
men
u screen?
Is the video signal inputted to pin (71) of IC3800 (A
V SWITCH)?
Chec
k the line betw
een pin (8) of J1101 and
pin (71) of IC3800.
Select INPUT
-2 on the input select men
u
screen to ha
v
e
a desired input signal.
If the INPUT
-2 char
acters on the men
u
screen are g
ra
y and impossib
le to select:
See if the video signal detection function w
o
rk
s
. Chec
k the line betw
een pin (10) of
J1101 and pin (76) of IC3800. Chec
k IC3800 (A
V SWITCH) and its
per
ipher
al circuits
.
Chec
k the line betw
een IC3800 and IC3807.
(Q3807, etc.)
Is the video signal outputted to pin (20) of IC3807 (MUL
TIPLEXER)?
Is the video signal outputted to pin (22) of the A
V
unit's connector (PB_P5404)?
Mak
e sure that the control signal is f
ed to
pins (3) and (22) of IC3807. Chec
k the line betw
een IC3807 and P5404.
(Q3803, Q3808, etc.)
Is the video signal inputted to pin (22) of the main unit's connector (PB_CN1800)? Is the video signal inputted to pin (2) of IC402 (L.P
.F
.) via the b
uff
er Q404?
Chec
k the B-to-B connector "PB".
Chec
k the line betw
een connector PB and
IC402.
(Q404, etc.)
Is the video signal inputted to pin (135) of IC400 (3D-YC & CHR
OMA) via the b
uff
er Q408?
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 IC400 and its per
ipher
al circuits
.