LG 75SM9400PTA Service Manual page 49

Standard Repair Process
Error
symptom
Check
input
signal
Check and fix
external device/cable
D. Function error
External device recognition error
Check technical
Y
information
Signal
input? - Fix information
- S/W Version
N
Revised date
External Input
N
Technical
and Component
information?
Recognition error
Y
HDMI/
DVI, Optical
Fix in
Recognition
accordance
error
with technical
information
14
Established
date
Replace Main B/D
Replace Main B/D
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