Sharp C6400U Service Manual page 124

LC-52/60/70LE640U/C6400U,LC-80LE633U/844U (1st Edition)
• Picture does not display.
COMPOSITE: No external input video [INPUT-6]
Is INPUT-6 selected on the input select menu screen?
NO
Select INPUT-6 on the input select menu
screen for the right input signal.
YES
Is there the COMPOSITE signal input at pin (AJ23) of
IC3303 (CPU)?
NO
Check the line between pin (10) of J510
and pin (AJ23) of IC3303.
YES
Is the T-CON PWB connected?
VBO_HTPDN (40pin), VBO_LOCKN (39pin) of P2604 become Low if there is no problem in
the connection.
YES
Are the V-By-One signal input to the pin of P2604?
VBO_CN_TXA+/- (36/37pin), VBO_CN_TXB+/- (32/33pin),
VBO_CN_TXC+/- (28/29pin), VBO_CN_TXD+/- (24/25pin).
YES
Check the panel module and harness.
No video (1)
COMPOSITE: No external input video [INPUT-7]
Is INPUT-7 selected on the input select menu screen?
YES
Is there the COMPOSITE signal input at pin (AK22) of IC3303
(CPU)?
YES
NO
NO
6 – 6
NO
Select INPUT-7 on the input select menu
screen for the right input signal.
NO
Check the line between pin (5) of J510 and
pin (AK22) of IC3303.
Check the panel module and harness.
Check IC3303 and its peripheral circuits.
(IC3501/IC3502/IC3503, etc.)