LG 42LA86 Series Service Manual page 99

Standard Repair Process
Error
LCD TV
symptom
No audio
Screen normal
C. Audio error
No audio/ Normal video
☞A24
Check user
menu > Off
Speaker off
Y
Cancel OFF
Check Speaker
disconnection
☞A25
N Check audio B+ 24V
of Power Board
Replace Power Board and repair parts
N
Disconnection
Y
Replace Speaker
Established
2012. 12 .06
date
Revised date
Y
Normal
voltage
N
Replace MAIN Board
End