Sharp Aquos LC 45GD5U, Руководство по обслуживанию

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48
LC-45GD5U
TROUBLE SHOOTING TABLE
(Continued)
<Composite video signal / S-video signal> input
No video output (2)
No video output when receiving UHF/VHF broadcasting
NO
No video output from external input <<INPUT
-3>>
Is INPUT
-3 selected in the input switching menu
screen? Are signals supplied to each terminal of IC3800(A
V SWITCH)?
When it cannot be selected since the characters INPUT
-3 on the menu screen are gray
.
Select INPUT
-3 and the input signal in the input
switching menu screen.
NO NO
<Composite video signal input> Is video signal supplied to pin 3 of IC3800? <S-video signal input> Are
Y
and C signal supplied to pins 5 and 7 of
IC3800 respectively?
Check between pin 8 of J1
106 and pin 3 of
IC3800. Check between pins 3 and 4 of SC1
105 and pins 5
and 7 of IC3800. Is S-video signal detection functioning normally? Check between pin 6 of SC1
105 and pin 6 of
IC3800. Is video signal detection functioning normally? Check between pin 1
1
of J1
106 and pin 2 of
IC3800.
YES YES
<Composite video signal input> Is video signal sent to pin 60 of IC3800? <S-video signal input>
Are y and C signals sent to pins 60 and 59 of IC3800 respectively?
NO
Is video signal sent to output terminal pin 17 of tuner (TU1
101)?
Check or replace the tuner’s peripheral circuits.
YES
NO
Check IC3800(A
V SWITCH) and its peripheral
circuits.
YES
<Composite video signal input> Is video signal supplied to pin 1 of IC3807 (MUL
TI_PLEXER)?
<S-video signal input>
Are
Y
and C signals supplied to pins 1 and 5 of IC3807 (MUL
TI_PLEXER) respectively?
NO
Check between IC3800 and IC3807. (Q3807, Q3805, etc.)
YES
<Composite video signal input> Is video signal sent to pin 20 of IC3807 (MUL
TI_PLEXER)?
<S-video signal input>
Are
Y
and C signals sent to pins 20 and 18 of IC3807 (MUL
TI_PLEXER) respectively?
NO
Are control signals supplied to pins 3 and 22 of IC3807?
YES
<Composite video signal input> Is video signal sent to pin 22 of
A
V_UNIT
connector (PB_P5404)?
<S-video signal input>
Are
Y
and C signals sent to pins 22 and 20 of
A
V_UNIT
connector (PB_P5404) respectively?
NO
Check between IC3807 and P5404. (Q3803, Q3808, Q3802, Q3809, etc.)
YES
<Composite video signal input> Is video signal supplied to pin 22 of MAIN_UNIT
connector (PB_CN1800)?
<S-video signal input>
Are
Y
and C signals supplied to pins 22 and 20 of MAIN_UNIT
connector (PB_CN1800 respectively?
NO
Check the FFC harness "PB".
YES
<Composite video signal input> Is video signal supplied to pin 2 of IC402 (L.P
.F) via buf
fer Q404?
<S-video signal input>
Are
Y
and C signals supplied to pins 8 and 6 of IC402 (L.P
.F) via buf
fer Q413 respectively?
NO
Check between connector PB and IC402. (Q404, Q413, etc.)
YES
<Composite video signal input> Is video signal supplied to pin 135 of IC400 (3D-YC & CHROMA) via buf
fer Q408?
<S-video signal input>
Are
Y
and C signals supplied to pins 135 and 149 of IC400 (3D-YC & CHROMA) via buf
fers Q408 and Q409 res
pectively?
YES
Check between pins 28 and 27 of IC402 and pin 135 of IC400. Check
Y
signal from pins 20 and 19 of IC402 to pin 135 of IC400/C signal from pin 22 of IC402 to pin 149 of IC400.
Are digital video signals sent from output terminals of IC400?
NO
Check IC400 and its peripheral circuits.
NO
Is video signal supplied to pin 7 of IC1
103 (LEVEL
ADJ)?
Is control signal for level adjustment supplied from pin 1 of IC1
105 to pin 6 of IC1
103?
YES
NO
Is tuner video signal supplied to pin 17 of IC3800 (A
V SWITCH)?
Check or replace IC1
105 (CONTROL) and the
peripheral circuits.
No video output when receiving digital broadcasting
NO
Is video signal from the digital unit supplied to A
V_UNIT
connector (DA, P1
105)?
Check the digital unit.
YES NO
YES
NO
Are digital video signals supplied to input pins 90- 122 of MAIN-UNIT
connector S2100?
Check the digital unit.