Sharp LC-42D43U - Page 28

LC-42D43U
4 – 5
<Composite video signal/S-video signal input> No video output (3)
No video output from external input <<INPUT-3>> Select INPUT-3 and the input signal on the input switching menu
screen.
Is INPUT-3 selected on the input switching menu screen? NO When INPUT-3 cannot be selected since the characters INPUT-3
on the menu
YES
Is the video signal detection function normal? Check between
J501 and pin 2 of IC501.
Is the S-video signal detection function normal? Check between
J503 and pin 42 of IC501.
Is signal fed to each input terminal of IC501 (AV SWITCH)?
<Composite video signal input>
Is video signal fed to pin 3 of IC501?
NO Check between J501 and pin 3 of IC501.
<S-video signal input>
Are Y and C signals fed to pins 5 and 7 of IC501 respectively?
NO Check between J503 and pins 5 and 7 of IC501.
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 respec-
tively?
NO Check IC501 (AV SWITCH) and peripheral circuits.
YES
<Composite video signal input>
Is video signal sent to pin 2 of TERMINAL_UNIT connector
(FC_SC501)?
<S-video signal input>
Are Y and C signals sent to pins 2 and 4 of TERMINAL_UNIT
connector (FC_SC501) respectively?
NO Check between IC501 and SC501. (Q501, Q502, Q503, Q504,
etc.)
YES
<Composite video signal input>
Is video signal fed to pin 2 of MAIN_UNIT connector
(FC_SC1101)?
<S-video signal input>
Are Y and C signals fed to pins 2 and 4 of MAIN_UNIT connector
(FD_SC1101) respectively?
NO Check the board-to-board cable “FC”.
YES
<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 (Broad-
com) via L.P.F. composed of Q2202 and Q2210 and via L.P.F.
composed of Q2203 and Q2211 respectively?
NO Check between SC1101 and IC3301. (Q2202, Q2210, etc.)/
(Q2203, Q2211, etc.)
YES
Are digital video (LVDS) signals sent from pins 37-42 and 45-48
of IC2602?
NO Check IC2602 and peripheral circuits.
Are digital video (COMOS) signal sent from IC8101 (DVODATA 0
~ 23, DVOCLKO, DVODE, DVOHSYNC, DVOVSYNC)?
NO Check IC8101 and peripheral circuits.
YES
Check LCD_CONTROL PWB.