Sharp LC-70LE740E Service Manual page 158

LC-60/70LE740E/RU,741E/S,743E,60LE840E/RU,841E/S,843E,80LE645E/RU,646E/S,648E (1st Edition)
No picture appears on EXT1 connected monitor during the ATV reception.
Does CVBS signal output from pin [19] of EXT1 (SC505)?
Does CVBS signal output from pin [5] of IC510?
(CAPLESS VIDEO AMP with LPF)
Does CVBS signal input to pin [3] of IC510?
Does CVBS signal output from pin [2] of IC507?
Is CVBS_OUT_MUTE [pin (1)] of IC507 at "L"?
Does CVBS signal input to pin [6] of IC507?
In the case of LE645, LE648 series, refer to (A)?
In the case of LE646 series, refer to (B)?
Check the line between IC507 and TUNER (TU1102).
(Q1106 etc...)
<During external connection> No picture on the monitor
NO
NO
NO
NO
NO
NO
(A)
YES Check the setting of an external input device that connects with
EXT1.
YES Check the line between SC505 and IC510.
YES Check the peripheral circuits of IC510.
YES Check the line between IC507 and IC510.
YES Check the line between IC3303 and IC507.
Check the peripheral circuits of IC3303.
YES Check the peripheral circuits of IC507.
Check the line between IC507 and TUNER (TU1104).
(Q1106 etc...)
6 – 57
(B)