LG 782LS User Manual

COLOR MONIT OR

SER VICE MANUAL

Website:http://biz.LGservice.com

E-mail:http://www.LGEservice.com/techsup.html

CAUTION

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

CHASSIS NO. : CL-29 F ACTORY MODEL: LB782G

MODEL: LCD 782LS (LB782G-GD)

*( ) ID LABEL MODEL No.

CONTENTS

- 2 -

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

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

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

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

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

DISASSEMBLY ....................................................... 7

BLOCK DIAGRAM AND DESCRIPTION ................ 8

ADJUSTMENT ....................................................... 11

TROUBLESHOOTING GUIDE .............................. 12

PRINTED CIRCUIT BOARD................................... 17

EXPLODED VIEW...................................................19

REPLACEMENT PARTS LIST ...............................21

PIN CONFIGURATION............................................25

SCHEMATIC DIAGRAM......................................... 26

SPECIFICATIONS

1. LCD CHARACTERISTICS

Type : TFT Color LCD Module Size : 17.0 inch (43.2 cm diagonal) Pixel Pitch : 0.264(H) x 0.264(V) Elecctrical Interface : LVDS Color Depth : 6-bits+FRC, 16,194,277 colors Size (mm) : 383.5(H) x 306(V) x 21.0(D) Typ Surface Treatment : Anti-Glare, Hard Coating (3H) Operating Mode : Normally white Backlight Unit : Four-CCFL (Cold Cathode

Fluorescent Lamp)

2. OPTICAL CHARACTERISTICS

2-1. Viewing Angle by Contrast Ratio

≥

Left : 70° Typ. , Right : -70° Typ. Top : 45° Typ. , Bottom : -65° Typ.

2-2. Luminance : 200 (min.) 250 (typ.)

2-3. Contrast Ratio : 250 (min) 400 (typ.)

3. SIGNAL (Refer to the Timing Chart)

3-1. Sync Signal

• Type : Separate TTL (Positive/Negative)

3-2. Video Input Signal

1) Type : R, G, B Analog

2) Voltage Level : 0~0.714 V a) Color 0, 0 : 0 Vp-p b) Color 7, 0 : 0.467 Vp-p c) Color 15, 0 : 0.714 Vp-p

3) Input Impedance : 75 Ω

3-3. Operating Frequency

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

4. POWER SUPPLY

4-1. Power

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

4-2. Power Consumption

5. ENVIRONMENT

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

(Ambient)

5-2. Relative Humidity : 5% ~ 95%

(Non-condensing)

6. DIMENSIONS (with TILT/SWIVEL)

Width : 419 mm (16.49'') Depth : 205 mm (8.07'') Height : 410 mm (16.14'')

7. WEIGHT (with TILT/SWIVEL)

Net. Weight : 6.8 kg (14.99 lbs) Gross Weight : 8.4 kg (18.52 lbs)

MODE

POWER ON (NORMAL)

STAND-BY

SUSPEND

OFF

POWER OFF

H/V SYNC

ON/ON OFF/ON ON/OFF

OFF/OFF

POWER CONSUMPTION

less than 45 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

H + 31.469 800 640 16 96 48 V – 70.09 449 350 37 2 60

H – 31.469 800 640 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 + 70.08 449 400 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 1125 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

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

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

Sync

Polarity

Frequency

DOT

Clock

Total Period

(E)

Video Active

Time (A)

Sync Duration

(D)

Back Porch

(F)

Front Porch

(C)

Resolution

- 5 -

1. MENU Button

Use this button to enter or exit the on screen display.

Use these buttons to choose or adjust items in the on screen display

AUTO Button

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

OPERATING INSTRUCTIONS

Front Control Panel

FRONT VIEW REAR VIEW

AUDIO DC OUT

D-Sub Signal Port

Power Connector

AUDIO DC OUT

Power (DPMS) Indicator

Power ON/OFF Button

Button

AUTO Button

Power Button

MENU Button

Power Indicator

SET Button

Button

• Brightness and Contrast can be adjusted directly without entering the On Screen Display (OSD) system. Touch the buttons to adjust the settings and then the OSD button to save all changes. The Brightness and Contrast functions are also available in the On Screen Display (OSD) menu.

100

* 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.

PROCESSING

AUTO CONFIGURATION

MENU, 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.

- 6 -

WIRING DIAGRAM

J801

PG4

J702

CN1

CN3

CN2

Connector Ass’y P/No.: 6631T11012W

Connector Ass’y P/No.:

6631T25008R

Connector Ass’y P/No.:

6631T20015A

Connector Ass’y P/No.:

6631T20008P

J706

J710

- 7 -

DISASSEMBLY

(a)

1) Set the Monitor face downward.

2) Remove four screws (a).

BACK COVER REMOVAL

3) Set the Monitor as picture.

4) Release the bottom & side latch.

7) Release the center positon latch.

5) Set the Monitor face upward.

6) Release the up side latch.

8) Set the Monitor face downward.

9) Remove the Back cover.

※ Caution: When you open the Back cover, Be careful! Dont stress the Control Board Connector.

(b) Latch Point

(b)

BLOCK DIAGRAM

- 8 -

Inverter

12V

BRT-CTL

Tx+/-,Hs,Vs,CLK,DEN

INV-CTL

EEPROM

(SYSTEM)

Analog

Signal

ADC

+ PLL

OSD

Scaling

GM5020

DC/DC Block

Regulator

2.5V

3.3V

MCU

L VDS Tx

POWER BOARD

DDC

(EDID)

12V(Inverter)

5.0V

90-264V

12V

Module Power (5V)

DSUB

(H/V Sync)

(R,G,B)

SDA, SCL

H SYNC

AC INPUT

DESCRIPTION OF BLOCK DIAGRAM

- 9 -

1. Input signal part.

There is one input which is analog. It comes from 15 pin D-Sub connector.

2. Pre-amp/ ADC / PLL / Video Controller.

This part amplifies the level of video signal 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 135.0MHz. 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 LCD module. Especially pre-amp / ADC / Video controller are merged to one chip ‘gm5020’ by Genesis.

3. Power Part.

This circuit is working of 90~260VAC(50/60Hz). The operation procedure is as follows:

1) AC Input voltage is rectified and smoothed by the bridge diodes(BD901) and the capacitor(C905).

2) The Rectified voltage(DC) is applied to the primary coil of the transformer(T901).

3) The control IC(IC901) generates switching pulse to turn on and turn off the primary coil of the transformer(T901).

4) Depending on turn ratio of the transformer, the secondary voltages appear at the secondary coils of the transformer(T901).

5) These secondary voltages(12V,5V) are rectified by each diodes(D903,D906) and operates other circuit.(Inverter,Scaler…etc)

4. 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.

5. Inverter

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

BLOCK DIAGRAM

- 10 -

EMI

COMPONENTS

LINE

100 ~ 240V

INPUT RECTIFIE R

AND FILTER

ENERGY

TRANSFER

OUTPUT RECTIFIE R

AND FILTER

12V

GND

SIGNAL

COLLENTION

PHOTO-COUPLER

ISOLATION

PWM CONTROL

CIRCUIT

HVDC

100KHz

PRIMARY

SECONDARY

50 ~ 60Hz

POWER BOARD

DESCRIPTION OF BLOCK DIAGRAM

1. EMI components.

This part contains of EMI components to comply with global marketing EMI standards like FCC 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

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