LG LM-D2540A Manual page 9

Muting circuit Troubleshooting (if MUTE)
IC301 PIN91 F-MUTE "HIGH" check
YES
Q791 "C" PORT "HIGH" check
YES
Q700/Q750 "C" PORT SIGNAL check
YES
Q700/Q750 replacement
IC301 PIN2 WOOFER-MUTE "HIGH" check
YES
Q741 "C" PORT "HIGH" check
YES
Q740 "C" PORT signal check
YES
Q740 replacement
NO
Muting mode check IC301 replacement
Q791 "E" PORT "HIGH" check
Q791 replacement
NO
normal
NO
Muting mode check IC301 replacement
NO
Q741 "E" PORT HIGH check
Q741 replacement
NO
normal
- 2-4 -
PATTERN check
NO
YES
PATTERN check