LG 26LH2000 Service Manual

Normal
 voltage?
Check various
voltages of Power
Board ( 5V,12V,20V
or 24V…)
No Video/
No audio
Check and
replace
MAIN B/D Y
Replace Power
Board and repair
parts
N
End
Standard Repair Process
A. Video error No video/ No audio 
Established
date 
Revised date 2008. 3 .05
2/13
LCD  TV
Error
symptom
2
 

A. Picture ProblemPicture broken/ Freezing
Y
N N
Check RF Signal level
Normal 
Signal?
Check RF Cable
Connection
1. Reconnection
2. Install Booster
Check
S/W Version
Booster menu
On
Off: Check
OffOn: Check
S/W Upgrade
 Check whether other equipments have problem or not.
 (By connecting RF Cable at other equipment)
  
 DVD Player ,Set-Top-Box, Different maker TV etc`
SVC 
Bulletin?
Replace
Main B/DCheck
Tuner soldering
Normal 
Picture?Y
N
Y
Close
Normal 
Picture?Y
Close
 Menu
Setup 
Booster . By using...

Color
error?Y
N
 Check
and replace
Link Cable
(LVDS) and
contact
conditionY
N
Replace Main B/D
Color
error?
Check error
color input
mode
Check color by input
-External Input
-COMPONENT
-RGB
-HDMI/DVI
Y
External device
/Cable
normal
External Input/
Component
error
Check
external
device and
cable
Y
External device
/Cable
normal
RGB/
HDMI/DVI
error
Check external
device and
cable
Replace Main B/DReplace Main B/D N
N
A. Video error
Color error 
NY
End
Replace module
Request repair
for external
device/cable...

Screen
normal?
NY
Check external
device
connection
conditionY
N
Check and
replace Link
Cable
Normal?
YN
Screen
normal?
Replace Main B/D
Replace
module
Check color condition by input
-External Input
-Component
-RGB
-HDMI/DVI
End
 Vertical/Horizontal bar, residual image, light spot
Request repair
for external
device
A. Video error
Vertical / Horizontal bar, residual image, 
light spot, external device color error 
 External device screen error-Color error
External 
Input
error
Connect other external
device...

B. Power error
No power
Power  LED
On?Y
N
DC Power on
by pressing Power Key
On Remote control
YN
Normal 
operation?
Check Power
On ‘”High”
Check Power cord
was inserted properly
Check
Power LED
Replace
Power
B/D
Measure voltage of each output of Power B/D
NY
Normal
voltage?
Replace Main B/D
N
Y
OK?
Replace Main B/D
N
Y
Normal?
Check ST-BY 5V
Replace Power B/D
N Y
Normal
voltage?
Replace Power
B/D
Y
Standard Repair Process
Established
date 
Revised date 2008. 3 .05
6/13
LCD  TV
Error
symptom
 ’09 years...

B. Power error
Off when on, off while viewing, power auto on/off
Error?N
Y
Check Power Off
Mode
Fix A/C code & Outlet
and describe 3 wave
length
Check A/C codeCheck for 3 wave lengthCheck outlet
Replace Main B/D
CPU
Abnormal 
(If Power Off mode
is not displayed)
Check Power B/D
voltageY
N
Replace Main B/D
Normal
voltage?
Replace Power B/D
Replace Power B/DNY
Normal?
End
 Caution
     Check and fix exterior
     of Power B/D Part
Established
date 
Revised date 2008. 3 .05
7/13
LCD  TV
Error
symptom...

No audio
Screen normal
Check user
menu  >
Speaker off
OffN
Y
Cancel OFF and describe
Check audio B+
20V or 24V of
Power Board
Normal
voltageY
N
Replace Power Board and repair parts
Check
Speaker
disconnectionN
Y
Replace Speaker 
Replace MAIN Board
End
C. Audio error
No audio/ Normal video  
Disconnection
Established
date 
Revised date 2008. 3 .05
8/13
LCD  TV
Error
symptom
Standard Repair Process
8
 

 Wrecked audio/discontinuation/noise is same after “Check input signal” compared to No audio
C. Audio error
Wrecked audio/ discontinuation/noise 
Wrecked audio/
Discontinuation/
Noise for 
all audio
Check and replace
speaker and
connector
Wrecked audio/
Discontinuation/
Noise only 
for D-TVWrecked audio/
Discontinuation/
Noise only 
for AnalogWrecked audio/
Discontinuation/
Noise only 
for External Input
Connect and check
other external
deviceN
Y
Normal
audio?
Check and fix external device
Replace Power...

D. General Function ProblemRemote control & Local switch checking
Y
N
1. Remote control (R/C) operating error
Move 
Power problem
Section
2. Local(Mechanical) switch operating errorCheck R/C itself
Operation
Normal
operating?
Normal
operating?Y
Close
Replace R/C
If R/C operate,
Explain the customer
cause is interference
from light in room.
Check R/C Operating
When turn off light
 in room
Check & Replace
Baterry of R/C
Check & Repair
Cable connection
Connector solder
Normal
operating?
Check B+ 5V
On Main...

Check technical
information
- Fix information
- S/W Version
N
Y
Technical 
information?
Check
input
signal
Signal
input?Y
N
External Input and
Component
Recognition error
Check and fix 
external device/cable
RGB,HDMI/
DVI, Optical
Recognition error
Replace Main B/DReplace Main B/D
Fix in
accordance
with technical
information
D. Function error
External device recognition error 
Established
date 
Revised date 2008. 3 .05
11/13
LCD  TV
Error
symptom
Standard Repair Process
11