LG LB504N-XL Service Manual

MENU

/AUTO

SOURCE/SELECT

COLOR MONIT OR

SER VICE MANUAL

CHASSIS NO. : CL-35
F ACT OR Y MODEL: LB504N

MODEL: L1510P (LB504N-XL)

CAUTION

BEFORE SERVICING THE UNIT,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.

CONTENTS

SPECIFICATIONS

- 2 -

1. LCD CHARACTERISTICS

Type : TFT XGA LCD Module
Size : 352.0(H) x 263.5(V) x 14.0(T)
Pixel Pitch : 0.297mm x 0.297mm
Color Depth : 6Bits + FRC/ 16,194,277 colors
Active Video Area : 15.0 inch

(304.128 x 228.096)
Surface Treatment : Anti-Glare, Hard Coating (3H)
Backlight Unit : Top/Bottom edge side 2CCFL
Electrical Interface : LVDS

Interface

2. OPTICAL CHARACTERISTICS

2-1. Viewing Angle by Contrast Ratio

≥

10
Left : 55° min., 60° typ
Right : 55° min., 60° typ
Top : 40° min., 45°typ
Bottom : 40° min., 45° typ

2-2. Luminance : 200(min.), 250(typ.)
2-3. Contrast Ratio : 200(min.), 300(typ.)

3. SIGNAL (Refer to the Timing Chart)

3-1. Analog Video Input

1) Video Input Range : 0~0.7V ± 5%

2) Video Termination Impedance : 75Ω ±5%

3) Sync Type : Separate TTL, Composite TTL
SOG(Sync On Green)

4) Sync Level : TTL Low ≤ 0.8V, High ≥ 2.0V

3-2. Digital Video Input

DDWG DVI Standard 1.0

3-3. Operating Frequency

Horizontal : 31 ~ 63kHz
Vertical : 56 ~ 75Hz

4. POWER SUPPLY

4-1. Power

100~240V, 50/60Hz 0.6A

4-2. Power Consumption

5. ENVIRONMENT

5-1. Operating Temperature: 10°C~35°C (50°F~95°F)

(Ambient)

5-2. Relative Humidity : 10%~80%

(Non-condensing)

5-3. MTBF : 40,000 Hours (Min.)

Lamp Life : 40,000 Hours (min.)

6. DIMENSIONS (with TILT/SWIVEL)

Width : 356mm (14.01'')
Depth : 229mm (9.01'')
Height : 380mm (14.96'')

Width : 356mm (14.01'')
Depth : 291.4mm (11.47'')
Height : 103.3mm (4.06'')

7. WEIGHT (with TILT/SWIVEL)

Net. Weight : 5.0kg (11.02 lbs)
Gross Weight : 6.6kg (14.55 lbs)

SPECIFICATIONS ................................................... 2

PRECAUTIONS ....................................................... 3

TIMING CHART ....................................................... 4

OPERATING INSTRUCTIONS ................................ 5

WIRING DIAGRAM ................................................. 8

BLOCK DIAGRAM ................................................... 9

DESCRIPTION OF BLOCK DIAGRAM................... 11

ADJUSTMENT ...................................................... 13

TROUBLESHOOTING GUIDE .............................. 14

PRINTED CIRCUIT BOARD................................... 18

EXPLODED VIEW...................................................21

REPLACEMENT PARTS LIST ...............................23

PIN CONFIGURATION............................................28

SCHEMATIC DIAGRAM......................................... 32

MODE

POWER ON (NORMAL)

STAND-BY

SUSPEND

DPMS OFF

POWER OFF

H/V SYNC

ON/ON
OFF/ON
ON/OFF

OFF/OFF

POWER CONSUMPTION

less than 30 W

less than 3 W

less than 3 W
less than 3 W
less than 3 W

LED COLOR

GREEN
AMBER
AMBER
AMBER

OFF

VIDEO

ACTIVE

OFF
OFF
OFF

- 3 -

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

- 4 -

VIDEO

SYNC

B

D

C

F

E

A

H / V

H (Pixels)
V (Lines)
H (Pixels)
V (Lines)
H (Pixels)
V (Lines)
H (Pixels)
V (Lines)
H (Pixels)
V (Lines)
H (Pixels)
V (Lines)
H (Pixels)
V (Lines)
H (Pixels)
V (Lines)
H (Pixels)
V (Lines)
H (Pixels)
V (Lines)
H (Pixels)
V (Lines)
H (Pixels)
V (Lines)
H (Pixels)
V (Lines)
H (Pixels)
V (Lines)

Sync

Polarity

+

–
–

+

–
–
–
–
–
–
–
–

+
+
+
+
+
+
+
+

–
–
–
–
–
–

+
+

Dot

Clock

25.175

28.322

25.175

30.24

31.5

31.5

36.0

40.0

50.0

49.5

57.2832

65

75

78.75

Frequency

31.468 KHz

70.0 Hz

31.468 KHz

70.0 Hz

31.469 KHz

60.0 Hz

35.0 KHz

66.67 Hz

37.861 KHz

72.8 Hz

37.50 KHz
75 Hz

35.156KHz

56.25 Hz

37.879 KHz

60.3 Hz

48.077 KHz

72.188 Hz

46.875 KHz

75.0 Hz

49.725 KHz

74.55 Hz

48.363 KHz

60.0 Hz

56.476 KHz

70.0 Hz

60.023 KHz

75.0 Hz

Resolution

640 x 350

720 x 400

640 x 480

640 x 480

640 x 480

640 x 480

800 x 600

800 x 600

800 x 600

800 x 600

832 x 624

1024 x 768

1024 x 768

1024 x 768

Total

Period

( E )

800
449
900
449
800
525
864
525
832
520
840
500

1024

625

1056

628

1040

666

1056

625

1152

667

1344

806

1328

806

1312

800

Video

Active

Time ( A )

640
350
720
400
640
480
640
480
640
480
640
480
800
600
800
600
800
600
800
600
832
624

1024

768

1024

768

1024

768

Blanking

Time

( B )

160

99

180

49

160

45

224

45

192

40

200

20

224

25

256

28

240

66

256

25

320

43

320

38

304

38

288

32

Sync

Duration

( D )

96

2

108

2

96

2

64

3

40

3

64

3

72

2

128

4

120

6

80

3

64

3

136

6

136

6

96

3

Back

Porch

( F )

48
60
55
34
48
33
96
39

128

28

120

16

128

22
88
23
64
23

160

21

224

39

160

29

144

29

176

28

Front

Porch

( C )

16
37
17
13
16
10
64

3

24

9

16

1

24

1

40

1
56
37
16

1
32

1
24

3
24

3
16

1

MODE

1

2

3

4

5

6

7

8

9

10

11

12

13

14

(MAC)

(TEXT)

OPERATING INSTRUCTIONS

MENU

/AUTO

SOURCE/SELECT

100

100

PROCESSING

AUTO CONFIGURATION

FRONT VIEW

See front control panel

REAR VIEW

Power Connector

D-Sub Signal Connector

DVI-l Connector

Front Control Panel

1. Power Button

Use this button to turn the display on or off.

<Power (DPMS) Indicator>

This Indicator lights up green when the display
operates normally. If the display is in DPM (Energy
Saving) mode, this indicator color changes to
amber.

2. Menu Button

Use this button to enter or exit the On Screen
Display.

3. Button

Use these buttons to choose or adjust items in the
On Screen Display.

Bring up Contrast and
Brightness adjustment.

1142 3

4. Button

Use these buttons to choose or adjust items in the
On Screen Display.

When adjusting your display
settings, always press the

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). The best display mode is 1024x768.

SOURCE/SELECT Button

5.

Use this button to enter a selection in the On
Screen Display.
When selecting input signal, press Source/Select
button before entering the OSD. This will change
input(DVI-I/D-SUB select button). The Default
setting is D-SUB.

6. Control Lock(Menu button, button)

CONTROLS LOCKED

CONTROLS UNLOCKED

Press the hold the MENU button and button for
3 seconds: the message “CONTROLS LOCKED”
appears.

You can unlock the OSD controls at any time by
pushing the MENU, button for 3 seconds:
the message “CONTROLS UNLOCKED” will
appear.

Positioning your display

※ Adjust the position of the panel in various ways for maximum comfort.

Tilt Range : -24˚~145˚

145˚ -24˚

Height Range : maximun 3.39inch (86.1mm)

Landscape & Portrait : You can rotate the panel 90

o

clockwise.

(* For detailed information, please refer to the Pivot Sofeware CD provided.)

* Make sure not to

touch the floor
when the head
rotates to use the
Pivot function.

Ergonomic

It is recommended that in order to maintain an ergonomic and comfortable viewing position, the forward tilt angle of the monitor should
not exceed 5 degrees.

Making use of USB (Universal Serial Bus)*

USB (Universal Serial Bus) is an innovation in connecting your different desktop peripherals conveniently to your computer.
By using the USB, you will be able to connect your mouse, keyboard, and other to your monitor instead of having to
connect them to your computer. This will give you greater flexibility in setting up your system. USB allows you to connect
chain up to 120 devices on a single USB port, and you can “hot” plug (attach them while the computer is running) or unplug
them while maintaining Plug and Plug auto detection and configuration. This monitor has an integrated BUS-powered USB
hub, allowing up to 2 other USB devices to be attached it.

USB connection

1. Connect the upstream port of the Display to the downstream port of the USB compliant PC or another hub using the
USB cable. (Computer must have a USB port)

2. Connect the USB compliant peripherals to the downstream ports of the monitor.

This is a simplified representation

of rear view.

To USB downstream port
of the USB compliant PC or
another hub cable

USB downstream Port

connect the cables from USB
compliant peripherals-such as
keyboard, mouse, etc

NOTE

To activate the USB hub function, the monitor must be connected to a USB compliant PC(OS) or another hub with the USB
cable(enclosed).

When connecting the USB cable, check that the shape of the connector at the cable side matches the shape at the connecting
side.

Even if the monitor is in a power saving mode, USB compliant devices will function when they are connected the USB ports(both
the upstream and downstream) of the monitor.

IMPORTANT: These USB connectors are not designed for use with high-power USB devices such as a video camera, scanner, etc.
LGE recommends connecting high-power USB devices directly to the computer.

P902

J1

CN1

CN3

CN2

J702

J704

J705

J501

P902

CN1

CN2

J1

J702

J501

Connector the Main PCB Ass’y and Inverter.

Connector Ass’y :
P/N: 6631T20008G

Connector Ass’y :
P/N: 6631T11012R

Connector Ass’y :
P/N: 6631T12002H

Connector Ass’y :
P/N: 6631T20015P

Connector the Control PCB Ass’y and Main PCB Ass’y.

Filter

BD

SMPS

Control

IC

TOP247

12V

5V

CON 5P

To main

D-Sub

DVI-I

R2/G2/B2

R1/G1/B1

R/G/B

Selection

(BA7657)

R/G/B

ADC IC

(AD9884)

Scaler IC

(MX88L250EC-X)

TMDS Receiver IC

(SIL141B)

Digital
Signal

LVDS IC

(THC63LVDM83R)

MICOM

( MTV312)

3.3 V

Regulator

2.5 V

Regulator

5 V

Regulator

12V 5VR

5V

3.3V

2.5V

3.3V 2.5V

RGB Data

3.3V

12V

Inverter

8Pin

MODULE

5VR

H/V Selection

Gate

H1

V1

H2

V2

H1/V1

H2/V2

H/V

3.3V

5VR

AC Inlet

SMPS Trans

Power 5Pin

Regulator

44mm

135mm

Power PCB

Main PCB

Control IC

Heat

sink

Heat

sink

64mm

120mm

150

mm

101mm

Power 5Pin

Inverter 8Pin

Control

6 pin

LCD Module

20 pin

D-Sub DVI-I

MICOM

Scaler

ADC

R/G/B

Selection

ADC

TMDS

Receiver

DESCRIPTION OF BLOCK DIAGRAM

- 11 -

1. Input signal switching part(BA7657).

There are two analog inputs which are analog and digital input.
They come from each 15 pin D-Sub and 24 pin DVI-I connector.

2. Video Controller Part.

This part amplifies the level of video signal for the digital conversion and converts from the analog video signal
to the digital video signal using a pixel clock.
The pixel clock for each mode is generated by the PLL.
The range of the pixel clock is from 25MHz to 80MHz.
This part consists of the Scaler, ADC and TMDS receiver .
The Scaler gets the video signal converted analog to digital, interpolates input to 1024 X 768 resolution signal
and outputs 8-bit R, G, B signal to transmitter.

3. Display Data Transmitter Part(LVDS).

This part transmit digital signal from the Scaler to the receiver of module.

4. Power Part.

This part consists of the one 5V, two 3.3V, and one 2.5V regulators to convert power which is provided 12V,
5V in Power board.

3.3V is provided for LCD panel and inverter, 5V is provided for micom and analog selection(BA7657).
Also, 5V is converted 3.3V and 2.5V by regulator. Converted power is provided for IC in the main board.

5. MICOM Part.

This part consists of EEPROM IC which stores control data, Reset IC and the Micom.
The Micom distinguishes polarity and frequency of the H/V sync are supplied from signal cable.
The controlled data of each modes is stored in EEPROM.

6. Inverter

The inverter converts from DC12V to AC 700Vrms and operate back-light lamp of module.

- 12 -

POWER BLOCK DIAGRAM

EMI

COMPONENTS

LINE

100 ~ 240V

INPUT RECTIFIER

AND FILTER

ENERGY

TRANSFER

OUTPUT RECTIFIER

AND FILTER

12V

5V

GND

SIGNAL

COLLENTION

PHOTO-COUPLER

ISOLATION

PWM CONTRO

L

CIRCUIT

HVDC

100KHz

PRIMARY

SECONDARY

50 ~ 60Hz

1. EMI components.

This part contains of EMI components to comply with global marketing EMI standards like FCC, VCCI CISPR,
the circuit included a line-filter, across line capacitor and of course the primary protection fuse.

2. Input rectifier and filter.

This part function is for transfer the input AC voltage to a DC voltage through a bridge rectifier and a bulk
capacitor.

3. Energy Transfer.

This part function is transfer the primary energy to secondary through a power transformer.

4. Output rectifier and filter.

This part function is to make a pulse width modulation control and to provide the driver signal to power switch,
to adjust the duty cycle during different AC input and output loading condition to achive the dc output stablize,
and also the over power protection is also monitor by this part.

5. Photo-Coupler isolation.

This part function is to feed back the dc output changing status through a photo transistor to primary controller
to achive the stablized dc output voltage.

6. Signal collection.

This part function is to collect the any change from the dc output and feed back to the primary through photo
transistor

DESCRIPTION OF BLOCK DIAGRAM

- 13 -

ADJUSTMENT

All adjustment are thoroughly checked and corrected
when the monitor leaves the factory, but sometimes
several minor adjustment may be required.
Adjustment should be following procedure and after
warming up for a minimum of 10 minutes.
Alignment appliances and tools.

- IBM Compatible PC

- Programmable Signal Generator.
(eg. VG-819 made by Astrodesign Co.)

- E(E)PROM with each mode data saved.

- Alignment Adapter and Software.

1. Adjustment for Factory Preset Mode

1) Run alignment program for LB504N on the IBM
compatible PC.

2) Select EEPROM All Init. command and Enter.

3) Display cross hatch pattern at Mode 1.

4) Select EDID WRITE command and Enter.

2. Adjustment for White Balance

1) Display color 0,0 pattern at Mode 13.

2) Set External Bright to MAX position and Contrast to
MAX Position.

3) Select PRESET START → BIAS CAL command
and Enter.

4) No attempt to manually adjust, BIAS data is auto­matically adjusted and saved to the EEPROM.

5) Display color 15,0 pattern at Mode 13.

6) Select DRIVE CAL command and Enter.

7) Color 1 (9300K) and Color 2 (6500K) are
automatically adjusted and saved to the EEPROM.

8) Select PRESET EXIT command and Enter.

Figure 1. Cable Connection

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

VGS

MONITOR

E

E

V-Sync On/Off Switch
(Switch must be ON.)

F

F

A

A

B

B

C

C

15

10

5

5

69

1

1

1

14

13

25

6

5V

5V

5V

4.7K

4.7K

4.7K

74LS06

74LS06

OFF ON

OFF

ON

11

Video Signal
Generator