LG LM-D2540A, Manual

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Muting circuit Troubleshooting (if MUTE)
IC301 PIN91 F-MUTE “HIGH” check
Q791 “C” PORT “HIGH” check
Q700/Q750 “C” PORT SIGNAL check
IC301 PIN2 WOOFER-MUTE “HIGH” check
Q741 “C” PORT “HIGH” check
Q740 “C” PORT signal check
Q740 replacement
Q700/Q750 replacement
Muting mode check IC301 replacement
Q791 “E” PORT “HIGH” check
Q791 replacement
normal
normal
Muting mode check IC301 replacement
Q741 “E” PORT HIGH check
Q741 replacement
PATTERN check
PATTERN check
YES
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO