Sharp AQUOS LC-20D42U, Service Manual

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35
LC-20D42U
TROUBLESHOOTING TABLE
(Continued)
<Component video signal/S-video signal input> No video output (2)
Yes
No
No
Yes
Yes
No
No
Yes
Check between J509 and pin 5 and 7 of IC501.
Check between J509 and pin 3 of IC501.
Is the video signal detection function normal?Check
between J509 and pin 42of IC501.
When INPUT-3 cannot be selected since the characters
INPUT-2 on the menu.
Select INPUT-3 and the input signal on the input switching
menu screen.
No video output from extermal input <<INPUT-3>>
Is INPUT-2 selected on the input switching menu screen?
Is video signal fed to pin 21 of IC507 (AV SWITCH)?
<Composite video signal input>
Is video signal sent to pin 60 of IC501?
<S-video signal input>
Are Y and C signals sent to pins 60 and 59 of IC501
respectively?
Check IC501 (AV SWITCH) and peripheral circuits.(Q501,
Q502,Q503,Q504,etc.)
Check between IC501.(Q501,Q502,Q503,Q504,etc.)
No
Yes
No
Yes
Check IC2602 and peripheral circuits.
Check between SC1101 and IC3301.(Q2202,Q2210,etc.)/
(Q2203,Q2211,etc.)
Are digital video (LVDS) signals sent from pins 37-42 and
45-48 of IC2602?
Check LCD_CONTROL PWB.
No
Are digital video (COMOS) signal sent from IC8101
(DVODATA 0-23,DVOCLKO,DVODE,DVOHSYNC,
DVOVSYNC)?
Check IC8101 and peripheral circuits.
Is the S-video signal detection function normal?Check
between J509 and pin 2 of IC501.
<Composite video signal input>
Is video signal fed to pin 3 of IC509?
Yes
<S-video signal input>
Are Y and C signals fed to pins 5 and 7 of IC501
respectively?
<Composite video signal input>
Is video signal fed to pin K25 of IC8101 (Broadcom) via
L.P.F. composed of Q2202 and Q2210?
<S-video signal input>
Are Y and C signals fed to pins K25 and L24 of IC8101
(Broadcom) via L.P.F. composed of Q2202 and Q2210
and via L.P.F. composed of Q2203 and Q2211
respectively?