LG L1811SG, Flatron L1811S, Flatron L1811SG-VL Service Manual

L1811S

COLOR MONIT OR

SER VICE MANUAL

CHASSIS NO. : CL-43
F ACT OR Y MODEL: L1811SG

MODEL: L1811S (L181 1SG-VL)

CAUTION

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

1. LCD CHARACTERISTICS

Type : TFT SXGA LCD
Size : 18 inch
Pixel Pitch : 0.2805 (H) x 0.2805 (V)
Color Depth : 8-bit, 16.777,216 colors
Electrical Interface : LVDS
Surface Treatment : Anti-Glare, Hard Coating(3H)
Operating Mode : Normally Black
Backlight Unit : 6-CCFL (Cold Cathode

Fluorescent Lamp)

2. OPTICAL CHARACTERISTICS

2-1. Viewing Angle by Contrast Ratio

≥

10
Left : -60° min., -80°(Typ) Right : +60° min., +80°(Typ)
Top :+60° min., +80°(Typ) Bottom : -60°min., -80°(Typ)

2-2. Luminance : 200(min), 250(Typ)
2-3. Contrast Ratio : 200(min), 350(Typ)

3. SIGNAL (Refer to the Timing Chart)

3-1. Sync Signal

• Type : Separate Sync,
SOG (Sync On Green)
Composite Sync

3-2. Video Input Signal

1) Type : R, G, B Analog

2) Voltage Level : 0~0.7 V

a) Color 0, 0 : 0 Vp-p
b) Color 7, 0 : 0.35 Vp-p
c) Color 15, 0 : 0.7 Vp-p

3) Input Impedance : 75 Ω

3-3. Operating Frequency

Horizontal : 30 ~ 83kHz
Vertical : 56 ~ 75Hz

4

. Max. Resolution

Analog : 1280 x 1024 / 75Hz

5. POWER SUPPLY

5-1. Power

: AC 100~240V, 50/60Hz , 1.0A

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(Min)

Lamp life : 40,000 Hours(Min)

7. DIMENSIONS (with TILT/SWIVEL)

Width : 370 mm (14.57'')
Depth : 222.5 mm (8.76'')
Height : 421 mm (16.57'')

8. WEIGHT (with TILT/SWIVEL)

Net. Weight : 6.0 kg (13.23 lbs)
Gross Weight : 7.6 kg (16.76 lbs)

CONTENTS

SPECIFICATIONS

- 2 -

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

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

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

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

WIRING DIAGRAM ................................................. 6

BLOCK DIAGRAM ................................................... 7

DESCRIPTION OF BLOCK DIAGRAM.....................8

ADJUSTMENT ...................................................... 10

TROUBLESHOOTING GUIDE .............................. 11

PRINTED CIRCUIT BOARD................................... 14

EXPLODED VIEW...................................................17

REPLACEMENT PARTS LIST ...............................19

PIN CONFIGURATION ...........................................22

SCHEMATIC DIAGRAM......................................... 24

MODE

POWER ON (NORMAL)

STAND-BY

SUSPEND

DPMS OFF

POWER S/W OFF

H/V SYNC

ON/ON
OFF/ON
ON/OFF

OFF/OFF

-

POWER CONSUMPTION

less than 53 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

-

less than 1 W

(@120V AC)

- 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

<< Dot Clock (MHz), Horizontal Frequency (kHz), Vertical Frequency (Hz), Horizontal etc... (µs), Vertical etc... (ms) >>

H + 31.469 800 640 16 96 48
V – 70.8Hz 449 350 37 2 60

H – 31.469 840 640 16 96 48
V – 59.94 525 480 10 2 33
H – 37.5 840 640 16 64 120
V – 75 500 480 1 3 16

H – 31.468 900 720 18 108 54
V + 70.09 449 400 12 2 35

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+/– 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+/– 68.681 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

Mode

H/V

Sort

1

2

3

4

5

6

7

8

9

10

11

12

13

25.175

28.321

25.175

31.5

40.0

49.5

57.283

65.0

78.75

100.0

92.978

108.0

135.0

640x350

70Hz

640x480

60Hz

640x480

75Hz

720x400

70Hz

800x600

60Hz

800x600

75Hz

832x624

75Hz

1024x768

60Hz

1024x768

75Hz

1152x870

75Hz

1152x900

65Hz

1280x1024

60Hz

1280x1024

75Hz

Sync

Polarity

Frequency

Dot

Clock

Total Period

(E)

Video Active Time

(A)

Sync Duration

(D)

Back Porch

(F)

Front Porch

(C)

Resolution

OPERATING INSTRUCTIONS

L1811S

PROCESSING

AUTO CONFIGURATION

FRONT VIEW

See Front Control Panel

REAR VIEW

Power Connect

D-Sub Signal
Connect

Front Control Panel

1. Power ON/OFF Button

Use this button to turn the monitor on or off.

2. Power Indicator

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

213 46 5

5. SELECT Button

Use this button to enter a selection in the On Screen Display.
Use this button to scanning auto adjust.

6.

AUTO Button

Use this button to enter a selection in the on screen
display.

3. MENU Button

Use these buttons to enter or exit the On Screen Display.

4.

▼▲◀▶

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

Button

* AUTO adjustment function

TO the AUTO button before
using OSD menu. This button is
for the automatic adjustment of the screen position, clock
and phase.
Note: Some signal from some graphics boards may not
function properly. If the results are unsatisfactory, adjust
your monitor’s Position, Clock and Phase manually.

MODULE

MATAL
FRAME

P902

CN1

CN2

CN3

CN4

CN7

CN6

CN5

J710

J705

J702

J703

Connector Ass’y P/N:

6631T11012P

Connector Ass’y P/N:

6631T25008R

Connector Ass’y P/N:

6631T12002L

Connector Ass’y P/N:

6631T20015R

B

)

R,G,B
differential

LVDS
(Low Voltage
Differential Signaling)

Data 8 Bit

Address

AVDD 3.3V
DVDD 3.3V

5V

AVDD 2.5V
DVDD 2.5V

AVDD3.3V
DVDD3.3V

AVDD2.5V
DVDD2.5V

5V

5V

12V

12V

5V

R,G,B, H/V Sync

..

Power Board

INVERTER

- 8 -

DESCRIPTION OF BLOCK DIAGRAM

1. Video Controller Part & Display Data Transmitter 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 135MHz.
This part consists of the Scaler, Flash-ROM IC which stores program data, Reset IC.
The Scaler gets the video signal converted analog to digital, interpolates input to 1280 x 1024 resolution signal and
outputs 8-bit R, G, B signal to transmitter.
Especially pre-amp / ADC / Video controller/ Transmitter are merged to one chip ‘Gm2121’ by Genesis.
This part transmit digital signal from the Scaler to the receiver of module.

2. Power Part

This part consists of the one 3.3V and one 2.5 regulators to convert power which is provided 5V in LIPS Board.
5V is provided for LCD Panel.
Also, 5V is converted 3.3V and 2.5V by regulator. Converted power is provided for IC in the main board.

- 9 -

Power Board Block Diagram

EMI

COMPONENTS

LINE

100 ~ 240V

INPUT RECTIFIER

AND FILTER

ENERGY

TRANSFER

OUTPUT RECTIFIER

AND FILTER

12V

5V

GND

SIGNAL

COLLECT-

ION

PHOTO-COUPLER

ISOLATION

PWM CONTROL

CIRCUIT

HVDC

100KHz

PRIMARY SECONDARY

50 ~ 60Hz

Operation description_Power

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
achieve the stabilized 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