Sharp LC-26GA4D, Service Manual

Page: 39 / 222

39
LC-26GA4D
LC-26GA4U
TROUBLE SHOOTING TABLE
(Continued)
YES YES YES
YES YES
YES YES
NO NO NO NO NO
NO NO
NO
YES YES YES YES YES YES
NO NO
NO
NO NO NO
YES
NO NO
<SUB SYSTEM>
Exter
nal input in troub
le <INPUT 3>
Is INPUT 3 selected in the input select men
u
screen?
Is there signal input at each input pin of IC3800 (A
V SWITCH)?
<Composite video signal input> Is there signal input at pin (3)? <S-video signal input> Are there
Y
-signal input at pin (5) and C-
signal input at pin (7)?
Select INPUT 3 and the input signal in the input select men
u
screen.
If signal name is g
ra
y and not selectab
le in
the men
u
screen
Is composite video signal detection functioning nor
mally? Chec
k
betw
een pin
(11) of J1106 and pin (12) of IC1102.
Is S-video signal detection functioning nor
mally? Chec
k betw
een pin (6) of
SC1105 and pin (6) of IC3800.
Chec
k betw
een pin (8) of J1106 and pin
(3) of IC3800. Chec
k betw
een pins (3), (4) of SC1105
and pins (5), (7) of IC3800.
<Composite video signal / S-video signal> input
<Composite video signal input> Are there MAIN
VIDEO signal output at pin (60) of IC3800 and SUB
VIDEO signal output at pin (56)
?
<S-video signal input> Are there MAIN
Y-signal output at pin (60) and MAIN C-signal output at pin (59) of IC3800, and SUB
Y-sig
nal output at pin (56) and SUB C-signal output at pin (55)?
<Composite video signal input> Are there video signal input at pin (2) of IC401 (MAIN L.P
.F
.) and at pin (2) of IC501 (SUB L.P
.F
.)?
<S-video signal input> Are there MAIN
Y-signal input at pin (2) and MAIN C-signal input at pin (6) of IC401, and SUB
Y-signal i
nput at pin (2) and SUB C-signal input at pin (6) of IC501?
<MAIN SYSTEM>
Chec
k betw
een IC401 and IC400.
<Composite video signal input> Is there video signal input at pin (85) of IC400 (MAIN
VIDEO CHR
OMA)?
<S-video signal input> Are there MAIN
Y
-signal input at pin (85)
and MAIN C-signal input at pin (90) of IC400 (MAIN
VIDEO CHR
OMA)?
Are there digital video signal outputs at pins (43), (44), (46)~(49), (54), (55) and (58) of IC400?
Chec
k IC400 (MAIN
VIDEO CHR
OMA) and
the per
ipher
al circuits
.
No Picture (2)
No Picture (3)
No
TV (U/V) picture output
Is there video signal output at output pin (17) of the tuner (TU1101/1102)? Are there video signal inputs at pins (7) and (1) of IC1103 (LEVEL ADJ)? Is each tuner video input to IC3800 (A
V
SWITCH) nor
mal?
Pin (17) (MAIN
TUNER IN) of IC3800
Pin (19) (SUB
TUNER IN) of IC3800
Chec
k the tuner (TU1101/1102) and its
per
ipher
al circuits
. Replace if necessar
y.
Are there inputs of le
vel adjustment control
signals at pins (6) and (2) of IC1103 (LEVEL ADJ) from pins (1) and (2) of IC1105? Chec
k IC1105 (CONTR
OL) and the per
ipher
al
circuits
. Replace if necessar
y.
Chec
k IC3800 (A
V SWITCH) and the
per
ipher
a
l circuits
.
Chec
k betw
een IC3800 and IC401/IC501.
Are there digital video signal inputs at pins (53), (54), (57)~(60), (51), (52) (RE0-7), pins(63)~(68), (61), (62) (GE0-7), pin
s (73)~(78), (69), (70) (BE0-7), pins
(81)~(86), (79), (80) (R
O0-7), pins (91)~(96), (89), (90) (GO0-7), pins (99), (100), (1), (2), (5), (6), (97), (98) (BO0-7), an
d pins (7)~(10) (HSYNC
,
VSYNC
, DE,
CLKIN) of IC3201 (L
VDS
TRANSMITTER)?
Are there digital video signal outputs at pins (49)(T
A1
–
), (48)(T
A1+), (47)(TB1
–
), (46)(TB1+), (44)(TC1
–
), (43)(TC1+), (41)(TCLK
–
), (42)(TCLK+), (40)(TD1
–
),
(39)(TD1+), (37)(T
A2
–
), (36)(T
A2+), (35)(TB2
–
), (34)(TB2+), (32)(TC2
–
), (31)(TC2+), (30)(TCLK2
–
),(29)(TCLK2+), (28)(TD2
–
), and (27)(TD2+) of IC3201?
<Composite video signal input> Is there video signal input at pin (85) of IC500 (SUB
VIDEO CHR
OMA)?
<S-video signal input> Are there SUB
Y
-signal input at pin (85)
and SUB C-signal input at pin (90) of IC500 (SUB
VIDEO CHR
OMA)?
Chec
k
betw
een IC501 and IC500.
Are there digital video signal outputs at pins (43), (44), (46)~(49), (54), (55) and (58) ofIC500?
Chec
k IC500 (SUB
VIDEO CHR
OMA) and
the per
ipher
a
l circuits
.
Replace the main PWB
, or chec
k betw
e
en
IC400/IC500 and IC3201. Chec
k IC3201 (L
VDS
TRANSMITTER) and
the per
ipher
al circuits
.
Chec
k the LCD CONTR
OL PWB
.