Read Sharp LC-46DH77E (serv.man5) Service Manual online
LC-42DH77E/RU/S/V, LC-46DH77E/RU/S/V
4 – 5
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.
input devices.
NO
MONITOR_MUTE signal [Pin (23) of IC503 (AV_SW.)] or MUTE-
A_ALL signal [Pin (21) of IC2003] will be “H”?
A_ALL signal [Pin (21) of IC2003] will be “H”?
YES
Check the peripheral circuits of IC503 and MUTE-A_ALL_LINE.
(D534, etc.)
(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.)
(Q510, Q511, Q512, Q513, etc.)
NO
Check IC1302 and its peripheral circuits.
The audio signal is not output (3)
No sound from HEADPHONE_OUTPUT terminal.
Is the HP_PLUG signal input to pin (90) of IC9101 (CPLD) from
pin (6) of a HEADPHONE_OUTPUT terminal (J1302)?
NO
Check the line between J1302 and IC9101.
(J1302, IC9101, etc.)
(J1302, IC9101, etc.)
YES
Is the audio signal output (HP_L/R) to pins (2, 3) of HEAD-
PHONE terminal (J1302)?
PHONE terminal (J1302)?
YES
Check the HEADPHONE terminal (J1302) and/or peripheral cir-
cuits.
cuits.
NO
Is HP-MUTE-LINE [pin (70) of IC9101 (CPLD)] at H?
YES
Check the peripheral circuits of IC9101 and HP-MUTE_LINE.
(Q1301, etc.)
(Q1301, etc.)
NO
Is audio signal (HP_L/R) output to pins (40, 42) of IC1302
(DSP)?
(DSP)?
YES
Check the line between IC1302 and J1302. (IC1305, etc.)
NO
Check IC1302 and its peripheral circuits.
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