LG FLATRON L2320A User manual

L2320A
COLOR MONITOR
SERVICE MANUAL
Website:http://biz.LGservice.com
CAUTION
BEFORE SERVICING THE UNIT,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
CHASSIS NO. : CL-46
MODEL: L2320A (L2320AL-AL**A)
( ) **Same model for SVC
Internal Use Only

CONTENTS
1. LCD CHARACTERISTICS
Type : TFT Color LCD Module
Active Display Area : 23inchs (58.4cm)diagonal
Pixel Pitch : 0.258(H) x 0.258(V)
Electrical Interface : TMDS
Color Depth : 8-bit, 16,777,216 colors
Size : 550.0(W)x360.5(H)x25.0(D)
Surface Treatment : Anti-Glare, Hard Coating(3H)
Operating Mode : Normally Black
Backlight Unit : Six-CCFL (Cold Cathode
Fluorescent Lamp)
2. OPTICAL CHARACTERISTICS
2-1. Viewing Angle by Contrast Ratio
≥ 10
Left : -85°(Typ) Right : +85°(Typ)
Top : +85°(Typ) Bottom : -85°(Typ)
2-2. Luminance : 150(min), 200(Typ)
2-3. Contrast Ratio : 300(min), 400(Typ)
3. SIGNAL (Refer to the Timing Chart)
3-1. Video Input
1)Signal Input : 15pin D-sub Connector/
DVI-D Connector, DVI-I Connector,
Composite video, S video, HDTV, DVD
2)Input Form : RGB Analog(0.7Vp-p/75 Ω), Digital,
S-VIDEO, CVBS, YPbPr(Y, Cb, Cc)
3-2. Sync Input
Horizontal : 30 ~ 96kHz
(DVI-I:~80kHz, DVI-D: ~71kHz)
Vertical : 56 ~ 85Hz
Input Form : Separate TTL,
Positive/Negative Composite TTL,
Positive/Negative SOG(Sync On Green)
DIGITAL
4. Max.Resolution
Analog -1920 x 1200@60Hz(1600 x 1200@75Hz)
Digital(DVI-I) -1600 x 1200@60Hz
Digital(DVI-D) -1280 x 1024@60Hz
5. POWER SUPPLY
5-1. Power Adaptor
DDC 2B Display
Input : DC 18.5V 4.5A, DC5V 0.5A
Media station
Input : AC 100~240V, 50/60Hz , 1.5A
Output : DC 18.5V 5.0A, DC 5V 0.8A
5-2. Power Consumption
6. ENVIRONMENT
6-1. Operating Temperature: 10°C~35°C (50°F~95°F)
(Ambient)
6-2. Relative Humidity : 10%~80%
(Non-condensing)
6-3. MTBF : 50,000 Hours(Typ.)
7. DIMENSIONS
Display(with TILT/SWIVEL)
Width : 587.5 mm (23.13'')
Depth : 260 mm (10.24')
Height : 446.5 mm (17.58'')
Media Station
Width : 129.6 mm (5.10'')
Depth : 205.6 mm (8.09')
Height : 191.6 mm (7.54'')
8. WEIGHT
Display(with Tilt/Swivel) : 11.56kg (25.49 lbs)
Media station : 2.7kg (5.95 lbs)
9. USB
USB standard :
Rev.1.0compliedSelf-poweredhub
Downstream power supply
: 500mA for each(MAX)
Communication speed : Full-12Mbps, Low-1.5Mbps
USB port : 1 Upstream port
2Downstream ports
SPECIFICATIONS
- 2 -
SPECIFICATIONS ................................................... 2
PRECAUTIONS ....................................................... 4
TIMING CHART ....................................................... 5
OPERATING INSTRUCTIONS ................................ 6
WIRING DIAGRAM ................................................. 8
BLOCK DIAGRAM ................................................... 9
DESCRIPTION OF BLOCK DIAGRAM...................10
ADJUSTMENT ....................................................... 11
TROUBLESHOOTING GUIDE .............................. 13
PRINTED CIRCUIT BOARD................................... 19
EXPLODED VIEW...................................................24
REPLACEMENT PARTS LIST ...............................28
PIN CONFIGURATION............................................41
SCHEMATIC DIAGRAM......................................... 46
MODE
POWER ON (NORMAL)
STAND-BY
SUSPEND
DPM OFF
POWER OFF
POWER CUT OFF S/W OFF
H/V SYNC
ON/ON
OFF/ON
ON/OFF
OFF/OFF
-
-
POWER CONSUMPTION
less than 98 W
less than 5 W
less than 5 W
less than 3 W
less than 3 W
less than 1 W
LED COLORVIDEO
ACTIVE
OFF
OFF
OFF
-
-
BLUE
AMBER
AMBER
AMBER
OFF
OFF
BLUE
BLUE
BLUE
BLUE
BLUE
OFF
Copyright 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only

- 3 -
Signal Connector Pin Assignment
Pin Signal (DVI-D)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
T. M. D. S. Data2-
T. M. D. S. Data2+
T. M. D. S. Data2/4 Shield
T. M. D. S. Data4-
T. M. D. S. Data4+
DDC Clock
DDC Data
Analog Vertical Sync.
T. M. D. S. Data1-
T. M. D. S. Data1+
T. M. D. S. Data1/3 Shield
T. M. D. S. Data3-
T. M. D. S. Data3+
+5V Power
Ground
(return for +5V,
H. Sync. and V. Sync.)
Pin Signal (DVI-D)
18
9
17 24
16
C1
C4
C3
C2
C5
16
17
18
19
20
21
22
23
24
C1
C2
C3
C4
C5
Hot Plug Detect
T. M. D. S. Data0-
T. M. D. S. Data0+
T. M. D. S. Data0/5 Shield
T. M. D. S. Data5-
T. M. D. S. Data5+
T. M. D. S. Clock Shield
T. M. D. S. Clock+
T. M. D. S. Clock-
Analog Red
Analog Green
Analog Blue
Analog H. Sync.
Analog Ground
T. M. D. S. (Transition Minimized Differential Signaling)
C1~C5 : DVI-I only
• DVI-D/ DVI-I Connector
Copyright 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only

- 4 -
Copyright 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
WARNING FOR THE SAFETY-RELATED COMPONENT.
•There are some special components used in LCD
monitor that are important for safety. These parts are
marked on the schematic diagram and the
replacement parts list. It is essential that these critical
parts should be replaced with the manufacturer’s
specified parts to prevent electric shock, fire or other
hazard.
•Do not modify original design without obtaining written
permission from manufacturer or you will void the
original parts and labor guarantee.
TAKE CARE DURING HANDLING THE LCD MODULE
WITH BACKLIGHT UNIT.
•Must mount the module using mounting holes arranged
in four corners.
•Do not press on the panel, edge of the frame strongly
or electric shock as this will result in damage to the
screen.
•Do not scratch or press on the panel with any sharp
objects, such as pencil or pen as this may result in
damage to the panel.
•Protect the module from the ESD as it may damage the
electronic circuit (C-MOS).
•Make certain that treatment person’s body are
grounded through wrist band.
•Do not leave the module in high temperature and in
areas of high humidity for a long time.
•The module not be exposed to the direct sunlight.
•Avoid contact with water as it may a short circuit within
the module.
•If the surface of panel become dirty, please wipe it off
with a softmaterial. (Cleaning with a dirty or rough cloth
may damage the panel.)
WARNING
BE CAREFUL ELECTRIC SHOCK !
•If you want to replace with the new backlight (CCFL) or
inverter circuit, must disconnect the AC adapter
because high voltage appears at inverter circuit about
650Vrms.
•Handle with care wires or connectors of the inverter
circuit. If the wires are pressed cause short and may
burn or take fire.
PRECAUTION
CAUTION
Please use only a plastic screwdriver to protect yourself
from shock hazard during service operation.

TIMING CHART
- 5 -
Copyright 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
VIDEO
SYNC
B
D
C
F
E
A
<< Dot Clock (MHz), Horizontal Frequency (kHz), Vertical Frequency (Hz), Horizontal etc... (µs), Vertical etc... (ms) >>
H + 31.47 800 640 16 96 48
V–70.09 449 350 38 2 60
H–43.27 832 640 56 56 80
V–85.01 509 480 1 3 25
H–37.5 840 640 16 64 120
V–75 500 480 1 3 16
H–31.47 900 720 18 108 54
V + 70.08 449 400 13 2 34
H + 37.879 1056 800 40 128 88
V + 60.317 628 600 1 4 23
H + 46.875 1056 800 16 80 160
V + 75.0 625 600 1 3 21
H + 53.674 1048 800 32 64 152
V + 85.061 631 600 1 3 27
H+/–49.725 1152 832 32 64 224
V+/–74.55 667 624 1 3 39
H–48.363 1344 1024 24 136 160
V–60.0 806 768 3 6 29
H–60.123 1312 1024 16 96 176
V–75.029 800 768 1 3 28
H + 68.677 1376 1024 48 96 208
V + 84.997 808 768 1 3 36
H+/–68.681 1456 1152 32 128 144
V+/–75.062 915 870 3 3 39
H+/–61.805 1504 1152 18 134 200
V+/–65.96 937 900 2 4 31
H + 63.981 1688 1280 48 112 248
V + 60.02 1066 1024 1 3 38
H + 79.976 1688 1280 16 144 248
V + 75.035 1066 1024 1 3 38
H + 75.000 2160 1600 64 192 304
V + 60.0 1250 1200 1 3 46
H + 93.750 2160 1600 64 192 304
V + 75.000 1250 1200 1 3 46
H + 74.556 2592 1920 136 200 336
V + 59.885 1245 1200 3 6 36
Mode H/V
Sort
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
25.175
25.175
31.5
36.0
28.324
40.0
49.5
56.25
57.283
65.0
78.75
94.5
100.0
92.978
108.0
135.0
162.0
202.5
193.25
640x350
70Hz
720x400
70Hz
640x480
75Hz
640x480
75Hz
640x480
60Hz
800x600
60Hz
800x600
75Hz
800x600
85Hz
832x624
75Hz
1024x768
60Hz
1024x768
75Hz
1024x768
85Hz
1152x870
75Hz
1152x900
65Hz
1280x1024
60Hz
1280x1024
75Hz
1600x1200
60Hz
1600x1200
75Hz
1920x1200
60Hz
H–31.47 800 640 16 96 48
V–59.94 525 480 10 2 33
Sync
Polarity Frequency
Dot
Clock
Total Period
(E)
Video Active Time
(A)
Sync Duration
(D)
Back Porch
(F)
Front Porch
(C)
Resolution
1~19 : D-SUB, 1~17 : DVI-I, DVI-D: 1~15

OPERATING INSTRUCTIONS
- 6 -
Copyright 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
FRONT VIEW
MEDIA STATION REAR VIEW
REAR VIEW
L2320A
Front Control Panel
Headphone/Earphone Input
Automatically mutes the speaker
volume when the headphones are
plugged in.
USB downstream ports
1. USB upstream port
2. Connect the P&D cable
3. Connect to the speaker including a built-in
amplifier(AMP)
4. PC signal inputs
5. Connect the audio cable to the *LINE OUT
jack of the PC sound card.
-PC1 : When connecting D-SUB/DVI-I
signal cable
-PC2 : When connecting DVI-D signal cable
6. AV Input ports
7. DVD(YPbPr) Input ports - 480i/576i
8. HDTV(YPbPr) Input ports - 720p/1080i
9. Connect the power cord
10. Power cut-off switch of the monitor
11. DVD(YPbPr), HDTV(YPbPr) Audio(L/R)
Input ports
1
2
4
5
10
6
89
3
7
11

- 7 -
Copyright 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
1. Remote Control Sensor
2. Power Button
Use this button to turn the display on or off.
<Power (DPMS) Indicator>
This Indicator lights up blue when the display
operates normally. If the display is in DPM (Energy
Saving) mode, this indicator color changes to
amber.
3. Source Button
Use this button to select an input signal
4. PIP Button
The sub-screen is changed in the
order shown below.
: SMALL -> LARGE -> OFF
The positions of SOURCE 1 and
SOURCE 2 can be transposed by
selecting SWAP on the remote control.
5. POP Button
The sub-screen is changed in the
order shown below.
: SMALL -> MEDIUM -> LARGE -> OFF
The positions of SOURCE 1 and
SOURCE 2 can be transposed by
selecting SWAP on the remote control.
6. MENU Button
Use this button to enter or exit On Screen Display.
7. CH. -+, VOL. -+
Use these buttons to choose or adjust items in the
On Screen Display.
8. AUTO Button
Front Control Panel
3 4 5 6 7 8 2 1
•DSUB ANALOG: 15-pin D-sub analog signal
•DVI-I ANALOG: DVI-I analog signal
•DVI-I DIGITAL: DVI-I digital signal
•HDTV YPbPr: HDTV
•DVI-D DIGITAL: DVI-D digital signal
•S-VIDEO: S video
•VIDEO: Composite video
•DVD YPbPr: DVD
CH.-+
•
Bring up Contrast and Brightness
adjustment. It is available to the PC
signal inputs only.
VOL.-+
Use these buttons to decrease or
increase the volume level.
When adjusting your display
settings, always press the
AUTO/SELECT button before entering the On Screen
Display(OSD). This will automatically adjust your
display image to the ideal settings for the current
screen resolution size (display mode). It is available to
the PC signal inputs only.
The best display mode is 1920x1200 @60Hz.
Use this to enter a selection in the On Screen Display.
CONTROLS LOCKED/UNLOCKED :
MENU and VOL.+
This function allows you to secure the
current control settings, so that they
cannot be inadvertently changed.
Press and hold the MENU button and VOL.+ button for 5
seconds: the message “CONTROLS LOCKED” appears.
You can unlock the OSD controls at any time by pushing
the MENU button and
VOL.+ button for 5 seconds:
the message “CONTROLS UNLOCKED” will appear.

- 8 -
Copyright 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
J04
J5
CN3
CN5
CN4
CN2
J905
J907
J906
J902 J903
J3
J2 J1
WIRING DIAGRAM(DISPLAY)
J18
J3
J4
J1
J2
J2
J8
J601
J704
J702
J6
WIRING DIAGRAM(Media Station)
Connector Ass’y P/N:
6631T20022E
Connector Ass’y P/N:
6850TAC006A
Connector Ass’y P/N:
6631T12004F
Connector Ass’y P/N:
6631T12004H
Connector Ass’y P/N:
6631T12004G
Connector Ass’y P/N:
6631T20010D
FAN P/N:
5900T02001A
Connector Ass’y P/N:
6631T20022E
Connector Ass’y P/N:
6631T20010D

BLOCK DIAGRAM
- 9 -
Copyright 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
Main Vi deo
In put
A
D
D
AC IN Power control
5VST
18. 5V
18VM
18VM(LCM/Inverter/USB Power)
Sub Video
In put
8MB 8MB
Frame Buffer
Memory(SDRAM)
5VC 2.5V
5VST
USB UP
LCM/Inverter/etc . Control signal & Audio L ine out
Scaler
(MX88L285U)
D-SUB DVI-I DVI-D Display
Output
ADC
(AD9888
205MHz)
ADC
(AD9883
140MHz)
Power control
Vid eoOut
CONNECTING
B/D
SCALER
B/D
POWER
B/D
8MB
Frame Buffer
Memory(SDRAM)
Composite
Video S-Video
Y PbPr
DVD(480i)
18VC
18VA
2.5V
5VC
5VST
DC/DC
(LM2676
5V)
DC/DC
(LM2596
5V)
DC/DC
(LM2596
Ad justable)
Vid eo
Out
Deinterlacer
(FLI2310)
Vid eo Decoder
(VPC3230D)
Tuner
AV B/D
Flash
ROM
(256KB)
Source
Flash
ROM
(512KB)
OSD
MCU
8bit
Latch
Audio Decoder
(MSP3410G-B11)
USB UP
USB UP
SIF
VIF
Y
C
18VA 5VA
TMDS RX
(SIL161B)
TMDS RX
(SIL161B) TMDS TX
(SIL160)
23inch
WUXGA
LCD Module
(1920 1200)
&
x
Inverter
18V-LCM
18VM
TMDS
USB UP
Control Signal
5VST Remote
Remote
5VST
AUDIO JACK
B/D
BRIDGE B/D
USB HUB
KEY CONTROL B/D POWERKEY B/D
18V-INVT
DTV(~1080i) YPbPr
DTV & DVD
Audio in
PC 1
Audio
in
PC 2
Audio
in
USB
UP
AV
Au dio
Speaker-Out
Head
Phone
Speaker-out
Line-out
Line-out
J10
J1 J2
U1
U12 U2
U14
U17 SPIN(23.0) U9
U27
U301
U302
J706
U601
J703 J705 J701
VPC- Y(7..0) VPC-C(7..0)
SPIN( 15..0)
AVSCALER
74ALVC162839
74ALVC162839
74ALVC162839 48BIT
AV PIN(15..0)
U7
U15
U18
MPINA (
MPINB(
23
..
0
)
23
..
0
)
AV PIN (15..0)
SPIN( 23..0)
MPINA (
15
..
0
)
15
..
0
)
SPIN(
HPTV IN(15..0)

- 10 -
Copyright 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
DESCRIPTION OF BLOCK DIAGRAM
1. Input Selection Circuit
This block is composed of 74VHCT126A(U10,U11)
and peripheral devices.
There are two inputs, Analog and Digital H/V Sync.
74VHCT126A(U10,U11) chooses one input and
outputs selected input through sync selection pin (Pin
1,4,13).
2. A/D Converter
This block is composed of AD9888 (U12) and
peripheral devices. AD9888(U12) includes A/D
converter, Pre-amp, and PLL.
The basic RGB signal (0.7Vp-p) is input to R,G,B pin
of AD9888(U12).
Input video signal is amplified, Phase locked , A/D
converted to 8bits digital signal by this IC(U12) And
send the Digital video signal to MX88L285(U62).
U12 makes clock for MX88L285(U201)
3. TMDS Receiver
This Block is composed of SiI161B (U2,U17) and
peripheral devices.
This ICs decodes TMDS Input signal from DVI-I(J1)
and DVI-D Pin (J2) and make 8bit digital signal to
send Digital signal to MX88L285(U201).
4. DDC controller
This block is composed of P89C662F(U43) and
peripheral devices. P89C662F(U43) controls
peripheral devices through IIC line.
Major functions are (1) to control Flash memory
through DDC-SCLA, DDC-SDAA of D-sub And (2) to
store EDID data in the EEPROM (U34,U49,U50)
5. Video Decoder
This block is composed of VPC3230D(U601) and
peripheral devices.
P89C662F(U43) controls this IC through IIC Line.
This IC analyzes input signal of CVBS, Y/C, Y/Pb/Pr
and output analyzed signal (8bit interlace signal) to
De-interlace block.
Analyzed signal has video control signals like
Contrast, Brightness, Sharpness, Color, tint signals
Including Adaptive Comb Filter.
6. DTV Circuit
This block is composed of AD9883(U14) and
peripheral devices. AD9883(U14) includes A/D
converter, Pre-amp, and PLL.
Input video signal is amplified, Phase locked , A/D
converted to 8bits digital signal by this IC(U14) And
send the Digital video signal to MX88L285(U201).
U14 makes clock for MX88L285(U201)
7. Audio Decoder
This block is composed of MSP3420G (U3) and
peripheral devices.
P89C662F(U43) controls this IC through IIC Line.
This IC analyzes Audio input signal through A/V Jack
and PC1/2 audio, DVD/DTV audio.
8. De-interlacer
This block is composed of FLI2310(U302) and
peripheral devices.
P89C662F(U43) controls this IC through IIC Line.
And this IC convert 8 Bit Interlace Y/UV signal to De-
interlace signal.
It output converted signal to Format Converter
(MX88L285)U201.
9. Format Converter
This block is composed of MX88L285(U201),
MX29LV004B(U28), EM638325(U26,U27) and
peripheral devices.
P89C662F controls this IC through parallel line.
MX88L285(U201) processes outputs of A/D
Converter and TMDS Receiver, DTV circuit,
De-interlace output and output processed 48 Bit
Digital signal to TMDS Transmitter.
MX88L285(U201) is Format Converter IC that receive
Digital signal and output proper frame signal to LCD
Module(1920 x1200).
10. Panel-Link Circuit
TMDS Transmitter (SIL160, U9) is the IC that
receives output digital signal of MX88L285(U201) and
output to LCD Module.
The signal format is Panel-link.
LCD Module has Panel-link receiver that is same
output of MX88L285(U201).
This is the best for reduction EMI problem and the
number of pin connector.
11. DC/DC Converter block
DC/DC Converters convert the input 18V to proper
1.8V, 2.5V, 3.3V, 5V, 8V for main board.
For shooting heat trouble, we use the DC/DC
converting IC.

- 11 -
ADJUSTMENT
Windows EDID V1.0 User Manual
Operating System: MS Windows 98, 2000, XP
Port Setup: Windows 98 => Don’t need setup
Windows 2000, XP => Need to Port Setup.
This program is available to LCD Monitor only.
1. Port Setup
a) Copy “UserPort.sys”file to
“c:\WINNT\system32\drivers”folder
b) Run Userport.exe
c) Remove all default number
d) Add 300-3FF
e) Click Start button.
f) Click Exit button.
2. EDID Read & Write
1) Run WinEDID.exe
2) Edit Week of Manufacture, Year of Manufacture,
Serial Number
a) Input User Info Data
b) Click “Update”button
c) Click “Write”button

- 12 -
Copyright 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
DVI-D Connector
220
IBM
Compatible PC
Parallel Port
Power inlet (required)
Power LED
ST Switch
Power Select Switch
(110V/220V)
Control Line
Not used
RS232C
PARALLEL
V-SYNC POWER
ST
VGSMONITOR
E
V-Sync On/Off Switch
(Switch must be ON.)
F
A
B
C
5V
E
F
A
B
C
15
10
5
5
69
1
1
1
14
13
25
6
5V
5V
4.7K
4.7K
4.7K
74LS06
74LS06
OFF ON
OFF
ON
11
Figure 1. Cable Connection
SVC OSD
1) Turn off the power switch at the front side of the display.
2) Wait for about 5 seconds and press MENU, PR+ and VOL+ with in 1 second interval.
3) The SVC OSD menu contains additional menus that the User OSD menu as described below.
a) ELAP. TIME CLEAR: Displays or clears the used time.
b) AUTO GAIN/OFFSET: Automatically sets the gain and offset value. (Pattern is used for D-Sub
window pattern.)
c) AUSTRALIA TV: The default value is off. When watching the Australian TV, turn it on.
d) R/G/B-GAIN: Allows you to set the R/G/B gain value manually.
e) R/G/B-OFFSET: Allows you to set the R/G/B-OFFSET value manually.
f) FAN: The default value is set to Auto. If set to Auto, the fan runs according to the surrounding
temperature. If set to On, the fan will run indefinitely as long as the power is on. (You can use this
option to check fan operation status. Make sure to set to Auto after inspection.)
g) TXT LANG: Set the proper text language (0~16).
h) RESET: The default value is set to Off. You can change the setting only after setting on after SVC
OSD menu change.

- 13 -
Copyright 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
TROUBLESHOOTING GUIDE
1. OUT OF ORDER ON POWER
Check Ctrl signal
‘PCB-PWR’
NO POWER
(POWER INDICATOR OFF)
Replace
the Power B’d
Check Stand-by
5V on Power B’d
Check
Connector or
5V Output
On Power B’d
Check
18.5V Output
On Power B’d
Fail
Fail
Fail
Replace
the Power B’d
Fail
Check
Reset signal for U43
(AV B’d :
U801 Pin#8)
Check
DC/DC Converter
Output
Check Device
AV B’d
:U803,U804,U805
Bridge B’d : U905
Fail
Check I2C Line
NCTL & PCTL
Level : >4V
Check Device
Main B’d :
U3,U4,U43,U44,U12
AV B’d : U702
Bridge B’d : U904
Key-control B’d : U1,U2
Check Device
Main B’d :
U3,U4,U43,U44,U12
AV B’d : U601,U302
Audio B’d : U3
*Check the PND
Cable connection
*Check the B’d to B’d
connection
Fail
Pass Pass
Pass
Pass
Pass
Pass
Pass
Check Point
(U43 Pin2, 3, 4, 5 )
Trouble
on NCTL
Trouble
on PCTL

- 14 -
Copyright 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
2. NO RASTER STATE
Check
U12(AD9888)
.MHS
.MVS
.MCLK
.DATA
NO RASTER ON ANALOG
SIGNAL
Replace Device
Main B’d : U9
AV B’d : U702
Check
Power Line
(U13)
Check LED
Status on
Display Head
Check
Ctrl signal
U9(Sil160) Pin#26
(TMDSTX-PDN)
Blue 3.3V LOW
Replace Device
Main B’d
: U201,U9
Replace the
U201(Scaler)
Find a
Soldering Error
or check the
oscillator(X6)
*Check the DTV Jack
Connection
- Y/Pb/Pr Jack check
*Check the other Device
- U26,U27(SDRAM)
- U2,U17(TMDS Receiver)
Check
Scaler(U201)
Output
. LHSYNC
. LVSYNC
. LCKA
. DATA
Fail
Fail
High
*Check Connector
*Check Ctrl Signal
(INVT-CTL/LCM-CTL
/LCM-PWR)
Check
Inverter or
LCD Module
Fail
Fail
Fail
Replace Device
Main B’d :U12
Amber
Pass
Pass
Pass
‘A’ Process

- 15 -
Copyright 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
NO RASTER ON DIGITAL
SIGNAL
Repeat
‘A’Process
Fail
Pass
Pass
Check
The EDID Data
Check U2,U17(Sil161B)
- H/V Sync
- Output Clock
- Output Data
- Power Down Ctrl Signal
(TMDSRX*-PDN)
Rewrite EDID
Data

- 16 -
Copyright 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
NO RASTER ON DTV SIGNAL
Repeat
‘A’Process
Fail
Pass
Pass
Pass
Pass
Check
Digital Switch for DTV
(Main B’d : U7,U15)
Check
Input Signal Connection
(Y/Pb/Pr?)
Not support 480i
Power S/W off and on after
remove the Input signal
cable
Resoldering
Or Replace
Device
Fail
Check
U14(AD9883)
*In/Out H/V Sync
*Output Data
*Check the Power
(3.3V-DTV)
*Replace Device

- 17 -
Copyright 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
NO RASTER ON AV SIGNAL
(CVBS, S-VIDEO, DVD Y/Pb/Pr)
Repeat
‘A’Process
Fail
Pass
Pass
Pass
Pass
Check
Digital Switch for AV
(Main B’d : U16)
Check
U601(VPC3230D)
*In/Out H/V Sync
*Output Data
*Input Signal
Resoldering
Or Replace
Device
Fail *
Check the Power
(5VA, 3.3VDD)
* Replace Device
NO RASTER ON TV SIGNAL
Check
The connection
Between AV B’d
And Tuner B’d
Fail
High
Pass
Pass
Check
Power(AV B’d)
*L702(5V)
*D802(33V)
Check
Tuner Output
*L701(TV-VIF)
Replace Device
. Main B’d:
U201, U9
Low Replace Device
. Main B’d: U9
. AV B’d: U702
Fail
* Check Connector
* Check Ctrl Signal
(INVT-CTL/LCM-CTL
/LCM-PWR
)
Fail
Check
U302(FLI2310)
*S2310-RESET
*In/Out H/V Sync
*Output Data
* Check the Power
:U303, U304
* Replace Device
Check the Input Jack and Cable

- 18 -
Copyright 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
3. SOUND TROBLE SHOOTING
NO SOUND OUTPUT
Check the
Line out Jack
or Speaker
Check the output of U3
.U3 Pin#24, 25, 27, 28
Replace the U3
(MSP3420G)
Check Connector
*AV B’d: J704
*Soun B’d: J2
Pass
Check Power Line
*U7 output(8V)
*5VA
Check
the sound output when
any sound source input
.C3(-), C4(-),
C12(-), C13(-)
Pass
Check Reset signal
for U3(Pin#21)
Pass
Check the
Oscillator(X3)
Pass
Pass
Replace the
Component of
Buffer circuit
Pass
Fail
Fail

PRINTED CIRCUIT BOARD
- 19 -
Copyright 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
1. MAIN BOARD (Component Side)
GUIDE LINE
U44 C29
C300 C42
U46
C320
U54
J26
R244
R242
R184
R41
U41
Q1
C260
R48
Q2
U4
R187
R185
C145
R81
R73
U5
L30 C71
L29
C413
C317
C72
R487
R486 R485
R484
C264
15
10
R271 R267
R225
5
R188
R230
R284
R282
R273
R232
R189
R40R39
R283 RA46
R186
RA70
C30
R35
R96
R95
ZD4
ZD10
ZD11
L5
C302
U40
D53
Q13
R236
R28
C316
C319
X3
25
20
C265
U43 RA43
C267
R31
R281
R280
R234
R36
RA45RA44
U8
C6
R233
ZD19
ZD8
ZD9
32
C299
C227
C58
J3
C322
C328
1
30
35
C266
40
R33
R140
R149
R148
D34
D2
ZD18
D14
29
31
30
C298
L13 L39
C57
C73
C34
U13
C48
C49
R248 R247 R246 R245
R243
R286
R179 R447
R37
RA55
R38
R32
U3
R143 R141
R157
R156
R153
R150
D38
D7
D35
28
27
26
C55 L6
L9
L12
C51
L7
R134 R114 R112 R110
C37
C262
25
R272
RA57 RA56
R285
RA58
L15
R481
C79
C84
R479
R480 R477 R478 R44
R142
R155
R154
D37
D36
ZD30
24
23
25
L8
L94
C40
C44
50
40
R111
30
R135 R133 R113
R5
R58
R57
R62
R60
30
R61
R59
20
L17L16
C110
C78
U49
Q3
D32
C371
R104R255
D48
J5
R270
R269
R268
21
C533
22
20
60
20
10
R4
R47
R63
U42
C614
R97
510
15
RA24RA23
60
C109
R79 R422
50
R80
Q4
D29
40
R266
ZD17 ZD20
C2
C1
19
18
17
L97
L99
70
1
U9
R130
R46
R249 R231 R224
U53
R29
C280
RA22RA21
70
30
ZD14
L34 L33
R106
R495
R70
14
C550
16
15
C569
R49
90 80
R52
100
RA29
RA33
RA31
RA83
RA71
R78
C108
C106
C104
C111
R421
R420
R77
RA20RA19
90
80
20
10
L35
R74 R497
R496
R72 R71
11
13
12
C98
L28
C534
L95
RA36 RA48
C32
R100
R51
R50
RA50
C99
C107
C105
C103
C102
C101
C100
RA18RA17
100
U12
120 110
1
R90
R76
R75
ZD15 ZD16
9
8
10
C138
C535
L96
C522
L93
C525
C521 C520
RA32
RA30
C551
L98
RA34
20 R145 15 R82 R136
RA13
R258
R261
R259 U10
J10
R498
R499 L14
7
6
5
30
20
RA35 RA47 RA49
R430 R429 R428
25
10
RA16 RA15 RA14
L10
C53
D1 D5 D9
4
3
2
5040
10
C361R69
AA
AB
AC
AD
AE
AF
5
L40
C595
C38
C41
R83
R265
R263
R262
R14
R12
U11
ZD13
L3
R89
R2
R1
R6
ZD12 R500
1
A
B
C
J6
U16
R98
1
C77
C76
X6
C358
R
T
U
V
W
Y
30
U28
RA10 RA12
RA11
20 10
R17 R23 R25 R15R13
R18 R132 R26
100
1
C16
C126
R11
D3
D6
L26
C70
J
K
L
M
N
P
RA8
RA9RA7
4030
R22
R21
90
R404
R402
C14
R16
R405
R403
R401
U201
C
D
E
F
G
H
RA1
50
R19
R20
D4
80
R400
R398
D42 D8
R399
RA76
RA80
RA74
21 22 23 24
25
2615 16 17 18 19 2091011121314345 678
A
B
12
R94
R92
C74
RA4
RA3
RA2
U2
60
RA5
70
C10
C11
RA6
D15
ZD3
ZD24
R10
J1
RA82 RA78
RA79
RA59 RA75RA60
20
R440
R144
10
C75
20 1 10
1
L4
L2
L1 C234
R42
R43
ZD2
C17
C4
C5
C405 R103
R102
R45
R312
ZD1 R198R318
ZD25 C96
C134
1
RA77RA81
80
RA68
U26
RA67
RA64 RA66
RA62
C54
C45
4030
U15
20
50
110
30 5040
U7
R121 R120 R122 R117
U34
R116
R200
R199
U50
R34 R311
D50 D27
2010
70
1
RA69 RA63
RA65
RA61 L23
R88
U14
80
RA38
RA37
RA40
R129
R119
R118
RA42 L18
R127
ZD7
ZD5
C162 C168
R109
C150 R105
LG MNT L2320AL(VSC) P/N : 6870T635A14
DATE :2003.06.09
30
60 50
10
U27
80 70
L66
L67 L24
C391
30
40
C113
C117
C123
R85
70
U17
R24
C124
R93
R99
R56
RA39
RA41
10
1
100
ZD6
C135
C166
C149L20
R107
D31
40 20 30
60
L83
C394
C492
L65
R91
50
C120 C119
60
C118
C121
C122
C401
R304
4030
R126
90
R30
R412
R410
D28
R115
R413
R411
R409
J2
L41
40
C596
50
C489
C388
C400
R324
R53 R54
1
J18
R55
C399
R175
R333
50
C167
R125
R124
R123
60 70
80
C161
R408
D23
R407
R406
D21
C169 L21 C163
L19
D30
D26
GUIDE LINE

- 20 -
Copyright 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
2. MAIN BOARD (Solder Side)
C414
C488
C329
C323
R483
32
L11
C47
C46
R482
31
30
29
L22
C257
28
27
26
25
24
23
C3C50C31
C263
D49
22
21
20
C33
C36
C28
C90
C87
C91
C94
19
18
17
C12
C43
C35
C13
C97
C93C88
C85
D16
D17
16
15
14
C39
C7
C95
C92
C182
C82
C80
C183
D18
13
12
11
C86
C89
C83
C81
C181
C180
9
8
10
R68
C52
R7
7
6
C67
5
R491
R490
R492
R67
R441
R8
L38
L37
L36
4
2
C66
3
C69
C538
C555
C571
C549
AF
AE
AD
AC
AB
AA
R9
A
CB
1
C68
C558
C537
C552
C548 C575
C545
C554
Y
W
V
U
T
R
C27
C22
C559
C561
C539
C565
C563
C542
P
N
M
L
K
J
C20
C26
C8
C21
C23
D12
D10
C553
C536
C556
C540
C560
C541
C557
H
G
F
E
D
C
C25
C24C18
C9
C19
D11
D13
C562
R424
2625
24232221
R427
201918171615
R66
14131211109876543
B
A
21
R426
R425
C519
C63
C61
C64
C15
C591
C587
C573
C65
C59
C56
C60
C62
C593
C589
C590
C582
C116
C115
C114
C583
C585
C579
C594
C592
C580
C127
C125
C128
R87
R86
C133
C112
C178
C179
C170
C581
C576
C588
R444
C577
C129
C130
D39 D33
C131
D40
C132
C172
C175
C171
C173
D22D24
C586
C584
C574
C177
C176C174
C160
GND
Y
PB
GND
GND
PR