Read Sharp LC-42AD5E (serv.man4) Service Manual online
LC-42AD5E/RU/S
4 – 5
No sound except from speakers (1)
No audio output from EXT1 (SCART) terminal.
Checklist:
1) Is the MUTE button on the remote control set to ON?
••• Set to OFF.
2) Check the connection to external devices.
••• Is there any improper connection?
Is audio signal sent to pins (3) (L-ch) and (1) (R-ch) of EXT1
(J1101)?
YES
Check the connection to EXT1 (J1101) and external devices.
NO
Is S-MUTE-LINE [IC1710 (100)] at H?
YES
Check IC1710 and its peripheral circuit, and S-MUTE line.
(Q1105, Q1106, etc.)
(Q1105, Q1106, etc.)
NO
Is audio signal sent from pins (24) (L-ch) and (23) (R-ch) of
IC3002?
IC3002?
NO
Check IC3002 or peripheral circuits.
YES
Check the audio signal output line from pins (24) (L-ch) and (23)
(R-ch) of IC3002 to pins (3) (L-ch) and (1) (R-ch) of EXT1.
(Q1108, Q1107, etc.)
(R-ch) of IC3002 to pins (3) (L-ch) and (1) (R-ch) of EXT1.
(Q1108, Q1107, etc.)
No sound except from speakers (2)
No audio output from EXT2 (SCART) terminal.
Checklist:
1) Is the MUTE button on the remote control set to ON?
••• Set to OFF.
2) Check the connection to external devices.
••• Is there any improper connection?
Is audio signal sent to pins (24) (L-ch) and (22) (R-ch) of EXT2
(J1101)?
YES
Check the connection to EXT2 (J1101) and external devices.
NO
Is S-MUTE-LINE [IC1710 (100)] or S2-MUTE-LINE [IC3003 (25)]
at H?
at H?
YES
Check IC1710/IC3003 and its peripheral circuit.
(S-MUTE_LINE, S2-MUTE_LINE, Q1101, Q1102, D309, D310,
etc.)
(S-MUTE_LINE, S2-MUTE_LINE, Q1101, Q1102, D309, D310,
etc.)
NO
Is audio signal sent from pins (22) (L-ch) and (21) (R-ch) of
IC3002?
IC3002?
NO
Check IC3002 or peripheral circuits.
YES
Check the audio signal output line from pins (22) (L-ch) and (21)
(R-ch) of IC3002 to pins (24) (L-ch) and (22) (R-ch) of EXT2.
(Q1104, Q1103, etc.)
(R-ch) of IC3002 to pins (24) (L-ch) and (22) (R-ch) of EXT2.
(Q1104, Q1103, etc.)
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