LG 79UF9500 Service Manual page 78

Standard Repair Process
Error
symptom
No audio
Screen normal
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Only for training and service purposes
C. Audio error
No audio/ Normal video
☞A20
Check user
menu > Off
Speaker off
Y
Cancel OFF
Check
Speaker
disconnection
☞A21+A18
Check audio B+
N
24V of Power
Board
Replace Power Board and repair parts
N
Disconnection
Y
Replace Speaker
8
Established
date
Revised date
Y
Normal
voltage
N
Replace MAIN Board End
8/16
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