LG CM 9520 Series Service Manual page 37

YES
Are the speaker cables connected correctly
between the speaker terminals on the unit
and the speakers?
YES YES
The sound is output from the speakers.
TRAINING MASTER TRAINING MASTER
NO NO
NO NO
3-8
Maker sure to connect the cables
to each specified connector tightly on the unit.
Connect the woofer cables to the WOOF SYSTEM
connectors on the rear panel.
Sound OK