Sharp LC-70LE632U Service Manual page 37

No video at UHF/VHF broadcast signal reception
Is the specified TV signal selected on the input select menu screen?
Is there the analog video signal output (CVBS) at pin (9) of
tuner (TU1105)?
NO
Check TU1105 and its peripheral circuits
(TU_SDATA: Pin4 of TU1105
TU_SCLK: Pin5 of TU1105, etc.).
YES
Is there the analog video signal input at pin (AK24) of IC3303
(CPU)?
NO
Check the line between IC3303 and TU1105, and
their peripheral circuits.
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 (3)
No video at digital broadcast signal reception
Are there the IF signal outputs (D_IF+/-) at the pins (11) and (10) of tuner
(TU1105)?
Check the line between TU1105 and IC4405, and
their peripheral circuits (C4463/C4464/R1158, etc.).
YES
Are there the TS signal outputs (ATSC_TS_D0/SYNC/CLK/VAL) at the
pins (33), (34), (37) and (38) of Demodulator (IC4405)?
Check the line between IC4405 and IC3303, and
their peripheral circuits (R4450/R3365/R3432, etc.).
YES
NO Check the panel module and harness.
NO Check IC3303 and its peripheral circuits.
(IC3501/IC3502/IC3503, etc.)
4 – 9
LC-70LE632U/633U
NO
NO