LG 49UF771V Service Manual page 71

Standard Repair Process
Error
symptom
Vertical/Horizontal bar, residual image, light spot
☞A6
Check color condition by input
-External Input
-Component
-HDMI
☞A8
Check Test pattern
External device screen error-Color error
Check S/W Version
Check
version
S/W Upgrade
Normal
screen?
End
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A. Video error
Vertical / Horizontal bar, residual image,
light spot, external device color error
Check external
Y
device
Screen
connection
normal?
condition
N
Replace
module
Check screen
condition by input
N
-External Input
-Component
-HDMI/DVI
Y
N
Y
☞ A7
Check and
Y
replace Link
Normal?
Cable
N
Request repair
for external
device
External
Connect other external
Input
device and cable
error
(Check normal operation of
External Input, Component,
RGB and HDMI/DVI by
Component
connecting Jig, pattern
error
Generator ,Set-top Box etc.
Connect other external
HDMI/
device and cable
DVI
(Check normal operation of
External Input, Component,
RGB and HDMI/DVI by
connecting Jig, pattern
Generator ,Set-top Box etc.
5
Established
date
Revised date
N
Screen
Replace Main/T-con B/D
normal?
(adjust VCOM)
For LGD panel
Y
Replace Main B/D
End
For other panel
Screen
normal?
Request repair for
external device
Screen
normal?
5/16
Replace
Module
N
Screen
normal?
Y
End
N
Replace
Main/T-con
B/D
Y
Y
N
Replace
Main /T-con
B/D
LGE Internal Use Only