Sharp LC-46D65E/RU, Service Manual

Page: 38 / 104

LC
-
52D65E/RU
4 – 4
The audio signal is not output (1)
No audio signal output from EXT1/EXT2 terminal.
Is there a audio output signal in pins (3/L-ch) and (1/R-ch) of
EXT1 (SC502)? YES Check the setting of an external input device that connects with
EXT1.
Is there a audio output signal in pins (3/L-ch) and (1/R-ch) of
EXT2 (SC501)? YES Check the setting of an external input device that connects with
EXT2.
NO
<EXT1>
Is SC-MUTE [pin (67) of IC9101 (CPLD)] at H? YES Check the peripheral circuits of IC9101 and SC-MUTE.
(Q503, Q505, etc.)
<EXT2>
Is SC2-MUTE [pin (65) of IC9101 (CPLD)] at H? YES Check the peripheral circuits of IC9101 and SC2-MUTE.
(Q502, Q504, etc.)
NO
<EXT1>
Is there a audio output signal in pins (39/SC1_OUT_L) and (38/
SC1_OUT_R) of IC503(AV_SW)? YES Check the line between IC503 and SC502.
<EXT2>
Is there a audio output signal in pins (37/SC2_OUT_L) and (36/
SC2_OUT_R) of IC503 (AV_SW)? YES Check the line between IC503 and SC501.
NO
Check IC503 and its peripheral circuits.
The audio signal is not output (2)
No audio signal output from AUDIO_OUTPUT terminal.
Is audio signal (L/R) output to pins (2, 4) of AUDIO_OUTPUT ter-
minal (J503)? YES Check the connection to AUDIO_OUTPUT terminal and external
input devices.
NO
MONITOR_MUTE signal [Pin (23) of IC503 (AV_SW.)] or MUTE-
A_ALL signal [Pin (21) of IC2003] will be “H”? YES Check the peripheral circuits of IC503 and MUTE-A_ALL_LINE.
(D534, etc.)
NO
Is audio signal (L/R) output to pins (5, 6) of IC1302 (DSP)? YES Check the line between IC1302 and J503.
(Q510, Q511, Q512, Q513, etc.)
NO
Check IC1302 and its peripheral circuits.