LG OLED77C9PTA Service Manual page 35

Standard Repair Process
Error
symptom
→ Abnormal audio/discontinuation/noise is same after "Check input signal" compared to No audio
Check input signal
- RF Signal
- External Input normal?
signal
C. Audio error
Wrecked audio / Discontinuation / Noise
Y
N
(When RF signal is not
received)
Request repair to external
cable/ANT provider
(In case of External Input
signal error)
Check and fix external
device
Established
Revised date
Wrecked audio/
Check and replace
Discontinuation/
speaker and cable
Noise for
all audio
Wrecked audio/
Discontinuation/
Replace Main B/D
Noise only
for D-TV
Wrecked audio/
Discontinuation/
Noise only for
Analog
Wrecked audio/
Discontinuation/
Noise only for
External Input
Connect and check
other external
device
11
date
☞A14 & A10/A11
Check audio
B+ Voltage (20V)
Y
Normal
voltage?
N
Replace Power B/D
Replace Main B/D
N
Normal
audio?
Y
Check and fix external device
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End