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 Digital signal level meter
. By using Diagnostics menu on OSD
   ( Menu
Setup
Diagnostic)
  - Signal strength (Normal : over 50%)
  - Signal Quality  (Normal: over 50%)
Normal 
Picture?Y
Contact with signal distributor
 or broadcaster (Cable or Air)N
N
Normal 
Picture?
YClose
N
Standard Repair Process
Established
date 
Revised date 2008. 3 .05
3/13
LCD  TV
Error
symptom
3
 
						

							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
Replace 
T-Con 
Board
And Adjust
VCOM
NY
Color
error?
LGD Module
OnlyOther Module
Color
error?
Check Test pattern
Standard Repair Process
Established
date 
Revised date 2008. 3 .05
4/13
LCD  TV
Error
symptom
4
 
						

							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 and cable(Check normal operation of
External Input, Component,
RGB and HDMI/DVI by
connecting Jig, pattern
Generator ,Set-top Box etc.N
Y
Replace
Main B/D
Screen
normal?
Check screen
condition by
input
-External Input
-Component
-RGB
-HDMI/DVI
Request repair for
external device
Component
error
RGB
errorHDMI/
DVI
Connect other external
device and cable(Check normal operation of
External Input, Component,
RGB and HDMI/DVI by
connecting Jig, pattern
Generator ,Set-top Box etc.
Replace 
Main B/D
Screen
normal?N
Y
Check S/W Version
YN
Check
 version
S/W Upgrade
YN
Normal
screen?End
Y N
Replace T-Con Board
And Adjust VCOMLGD Module Only
Replace
Module
Other Module
Replace module
in abnormal displaying
after exchanging T-Con B'd  
Screen
normal?End
Established
date 
Revised date 2008. 3 .05
5/13
LCD  TV
Error
symptom
Standard Repair Process
Check Test pattern
5
 
						

							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 new model apply mechanical power switch
      to reduce power consumption in stand-by status.
      If mechanical power switch off
      
 Doesn’t turn on by remote control
       Doesn’t appear LED light
           Please refer to the A21 Page
6
. Stand-By: Red
. Operating: Green
Check & Repair
Mechanical Power switch
on Local control of TV
Close
 
						

							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
Standard Repair Process
7
Status
Power off List
Explanation
Normal"POWEROFF_REMOTEKEY" Power off by REMOTE CONTROL
"POWEROFF_OFFTIMER"         Power off by OFF TIMER
"POWEROFF_SLEEPTIMER" Power off by SLEEP TIMER
"POWEROFF_INSTOP" Power off by INSTOP KEY
"POWEROFF_AUTOOFF" Power off  by AUTO OFF
"POWEROFF_ONTIMER" Power off by ON TIMER
"POWEROFF_RS232C" Power off by RS232C
"POWEROFF_RESREC" Power off by Reservated Record
"POWEROFF_RECEND" Power off by End of Recording
"POWEROFF_SWDOWN" Power off by S/W Download
"POWEROFF_UNKNOWN" Power off by unknown status except listed case
Abnormal"POWEROFF_ABNORMAL1"Power off by abnormal status except CPU trouble
"POWEROFF_CPUABNORMAL"Power off by CPU Abnormal
*  Please refer to the all cases which
    can be displayed on power off mode.
Abnormal 
1
 
						

							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 B/DNY
Normal
voltage?
Check input
signal
-RF
-External Input
signal
Signal 
normal?
(When RF signal is not
received)
Request repair to external
cable/ANT providerY
Check audio 
B+ Voltage (20V or 24V)Replace Main B/D
(In case of
External Input
signal error)
Check and fix
external device
Replace Main B/D
N
End
Established
date 
Revised date 2008. 3 .05
9/13
LCD  TV
Error
symptom
Standard Repair Process
9
 
						

							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 B/D
Normal
Voltage?
Close
NN
Check 5v on Power B/D
Replace Power B/D or
Replace Main B/D
(Power B/D don’t have problem)
Check IR
Output signal
Normal
Signal?
NY
Repair/Replace
IR B/D
N
Replace
Main B/D
Y
Y
N
Check R/C
Operation
Normal
operating?
Y
Check & Repair
Cable connection
Connector solder
Normal
operating?Close
N
Check & Replace
Assembly status
(Key PCB + tool )
Check Key
Output signal
Y
Normal
operating?Close
N
Normal
Signal?
Repair/Replace
Local switch B/D
NReplace
Main B/D
Y
Standard Repair Process
Established
date 
Revised date 2008. 3 .05
10/13
LCD  TV
Error
symptom
10
 
						

							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