LG 28LM4 0B-PU Series, Service Manual, Page: 28 / 69

A. Video error
Vertical / Horizontal bar, residual image,
light spot, external device color error
Established
date
Revised date
5/13
Error
symptom
Standard Repair Process
Vertical/Horizontal bar, residual image, light spot
light s s pot, external d d evice color e e rror
Replace
Module
ත
A6
Screen
normal?
N
Y
Check
external
device
connection
condition
Y
N
Check and
replace Link
Cable
Normal?
Y
N
Screen
normal?
Replace Main/T-con B/D
Check color condition by input
-External Input
-HDMI
Y
N
For BOE panel
Screen
normal?
A6
ත
A7
N
Y
Replace
module
End
Request repair
for external
device
ත A8
Replace Main B/D
End
Check Test pattern
For other panel
External device screen error-Color error
Check screen
condition by input
Check S/W Version
N
Check
External
Component
Connect other external
device and cable
(Check normal operation of
External Input, Component,
RGB and HDMI/DVI by
connecting Jig, pattern
N
Y
Replace
Main/T-con
B/D
Screen
normal?
condition by input
-External Input
-Component
-HDMI/DVI
Check S/W Version
Y
N
Check
version
S/W Upgrade
External
Input
error
Component
error
Generator ,Set-top Box etc.
Request repair for
external device
HDMI/
DVI
Connect other external
device and cable
(Check normal operation of
Replace
Screen N
Y
pg
N
Normal
screen?
(Check normal operation of
External Input, Component,
RGB and HDMI/DVI by
connecting Jig, pattern
Generator ,Set-top Box etc.
p
Main /T-con
B/D
normal?
Y
End
- 28 -
2019