Sharp LC-26D43U Service Manual page 31

TROUBLESHOOTING TABLE
<Component video signal/S-video signal input> No video output (2)
No video output from extermal input <<INPUT-3>>
Yes
Is INPUT-2 selected on the input switching menu screen?
Yes
Is video signal fed to pin 21 of IC507 (AV SWITCH)?
<Composite video signal input>
Is video signal fed to pin 3 of IC509?
<S-video signal input>
Are Y and C signals fed to pins 5 and 7 of IC501
respectively?
Yes
<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?
Yes
<Composite video signal input>
Is video signal fed to pin K25 of IC1801 (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?
Yes
Are digital video (LVDS) signals sent from pins 37-42 and
45-48 of IC2602?
Are digital video (COMOS) signal sent from IC8101
(DVODATA 0-23,DVOCLKO,DVODE,DVOHSYNC,
DVOVSYNC)?
Yes
Check LCD_CONTROL PWB.
No
Select INPUT-3 and the input signal on the input switching
menu screen.
No
When INPUT-3 cannot be selected since the characters
INPUT-2 on the menu.
Yes
Is the video signal detection function normal?Check
between J509 and pin 42of IC501.
Is the S-video signal detection function normal?Check
between J509 and pin 2 of IC501.
No
Check between J509 and pin 3 of IC501.
Check between J509 and pin 5 and 7 of IC501.
Check IC501 (AV SWITCH) and peripheral circuits.(Q501,
Q502,Q503,Q504,etc.)
No
Check between IC501.(Q501,Q502,Q503,Q504,etc.)
Check between SC1101 and IC3301.(Q2202,Q2210,etc.)/
No
(Q2203,Q2211,etc.)
No
Check IC2602 and peripheral circuits.
No
Check IC8101 and peripheral circuits.
31
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LC-26D43U