LG 84LA980T-DC (CHASSIS:LT34E) Service Manual ▷ View online
A. Video error
Picture broken/ Freezing
Standard Repair Process
Established
date
Revised date
3/16
LCD TV
Error
symptom
2013.01.31
Picture broken/ Freezing
A3
By using Digital signal level meter
Revised date
3/16
☞
A3
Check RF Signal level
. By using Digital signal level meter
. By using Diagnostics menu on OSD
. By using Diagnostics menu on OSD
( Setting
→ Set up→ Manual Tuning → Check the Signal )
- Signal strength (Normal : over 50%)
- Signal Quality (Normal: over 50%)
- Signal Quality (Normal: over 50%)
Y
Normal
Signal?
Check whether other equipments have problem or not.
(By connecting RF Cable at other equipment)
→ DVD Player ,Set-Top-Box, Different maker TV etc`
N
N
Check RF Cable
Connection
Check
DVD Player ,Set Top Box, Different maker TV etc
SVC
Check
T
ld i
Y
Close
Normal
Y
☞
A4
1. Reconnection
2. Install Booster
S/W Version
S/W Upgrade
Bulletin?
Tuner soldering
Y
Close
Picture?
Contact with signal distributor
N
Normal
N
N
Replace
Main B/D
Normal
Picture?
N
Contact with signal distributor
or broadcaster (Cable or Air)
Normal
Picture?
Y
Y
Close
Close
3
A. Video error
Color error
Standard Repair Process
Established
date
Revised date
4/16
LCD TV
Error
symptom
2013.01.31
Color error
Revised date
4/16
Color
Y
※
Check
and replace
Link Cable
Link Cable
Y
Replace Main B/D
Color
Check color by input
-External Input
-External Input
COMPONENT
☞
A6
Y
Replace module
Color
☞
A7
error?
N
(EPI) and
contact
condition
contact
condition
N
Replace Main B/D
error?
Check error
-COMPONENT
-AV
-HDMI
-AV
-HDMI
N
End
Replace module
error?
color input
mode
mode
Y
External device
/C bl
External Input/
C
t
Check
external
external
R l
M i /FRC B/D
Ch k T t
tt
☞
A8
/Cable
normal
Component
error
external
device and
cable
device and
cable
Replace Main/FRC B/D
N
Request repair
Check Test pattern
Y
External device
Check external
N
for external
device/cable
External device
/Cable
normal
HDMI
error
device and
cable
cable
Replace Main/FRC B/D
4
A. Video error
Vertical / Horizontal bar, residual image,
Established
date
Revised date
5/16
LCD TV
Error
symptom
Standard Repair Process
2013.01.31
Vertical/Horizontal bar, residual image, light spot
light spot, external device color error
Replace
Module
Module
Revised date
5/16
Screen
normal?
Y
Check external
device
connection
device
connection
Y
Check and
replace Link
Cable
replace Link
Cable
Normal?
N
Screen
normal?
Replace Main/FRC B/D
(adjust VCOM)
(adjust VCOM)
Check color condition by input
-External Input
-Component
-External Input
-Component
HDMI
N
Module
Screen
normal?
☞
A6
☞
A7
N
condition
N
Cable
Y
(adjust VCOM)
Replace
module
module
-HDMI
End
Request repair
for external
for external
☞
A8
Y
Replace Main B/D
For LGD panel
End
device
A8
External device screen error-Color error
Check Test pattern
For other panel
External
Input
error
Connect other external
device and cable
device and cable
N
Replace
Screen
Check screen
condition by input
-External Input
-Component
-HDMI/DVI
condition by input
-External Input
-Component
-HDMI/DVI
Check S/W Version
N
Check
version
(Check normal operation of
External Input, Component,
RGB and HDMI/DVI by
connecting Jig, pattern
Generator ,Set-top Box etc.
External Input, Component,
RGB and HDMI/DVI by
connecting Jig, pattern
Generator ,Set-top Box etc.
Y
Replace
Main/FRC
B/D
Main/FRC
B/D
normal?
Request repair for
Component
error
Y
S/W Upgrade
external device
HDMI/
DVI
Connect other external
device and cable
device and cable
(Check normal operation of
E t
E t
l I
t C
t
Replace
Main /FRC
Main /FRC
Screen
normal?
N
Y
N
Normal
screen?
External Input, Component,
RGB and HDMI/DVI by
connecting Jig, pattern
Generator ,Set-top Box etc.
RGB and HDMI/DVI by
connecting Jig, pattern
Generator ,Set-top Box etc.
Main /FRC
B/D
B/D
normal?
Y
End
5
B. Power error
No power
Standard Repair Process
Established
date
Revised date
6/16
LCD TV
Error
symptom
2013.01.31
No power
DC Power on
N
R l
☞
A17
☞
A18
Revised date
6/16
Power LED
On?
Y
N
DC Power on
by pressing Power Key
On Remote control
by pressing Power Key
On Remote control
Y
N
Normal
operation?
Check Power
On ‘”High”
On ‘”High”
Check Power cord
Check
Logo LED
Logo LED
Replace
Power
B/D
Power
B/D
Y
OK?
Replace Main B/D
. Stand-By: Red or Turn Off
. Operating: Turn Off
. Operating: Turn Off
Check Power cord
was inserted properly
was inserted properly
Measure voltage of each output of Power B/D
Replace Main B/D
N
Normal?
☞
A18
Y
Normal
voltage?
Replace Main B/D
Y
Y
※
N
g
Check ST-BY 3.5V
Replace Power B/D
N
Y
Normal
voltage?
☞
A18
Close
Replace Power
B/D
B/D
6
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