LG FPD1800 Service Manual

COLOR MONIT OR

SER VICE MANUAL

CHASSIS NO. : CL-1 1

MODEL: FPD1800, LG881Y

CAUTION

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

1. LCD CHARACTERISTICS

Type : Color Active Matrix TFT LCD Size : 18.1inch (45.97cm) Pixel Pitch : 0.2805mm(H) x 0.2805mm(V) Pixel Format : 1280 x 1024 pixels

RGB Stripe Arrangement Color Depth : 8-bit, color (24 bits) Active Video Area : 359mm x 287mm Surface Treatment : Anti-Glare, Hard Coating (3H) Backlight Unit : CCFL (Cold Cathode

Fluorescent Lamp) Electrical Interface : DVI-D

2. OPTICAL CHARACTERISTICS

2-1. Viewing Angle by Contrast Ratio

≥

10 Left : 80° Right : 80° Top : 80° Bottom : 80°

2-2. Luminance : 200 min.(Center of screen) 2-3. Contrast Ratio : 200 min : 1

3. SIGNAL (Refer to the Timing Chart)

3-1. Type : TMDS Digital 3-2. Voltage Level : 3.3V

3-3. Input Impedance : 50Ω

3-4. Operating Frequency

Horizontal : 64 kHz Vertical : 60 Hz

4. POWER SUPPLY

4-1. Power Adaptor

Input : AC 90~264V, 50/60Hz 1.4~0.7A Output : DC 12V 5.8A

4-2. Power Consumption

5. ENVIRONMENT

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

(Ambient)

5-2. Relative Humidity : 5% ~ 90%

(Non-condensing)

5-3. Altitude : 0~10,000 feet

6. DIMENSIONS (with TILT/SWIVEL)

Width : 434.0mm (17.09'') Depth : 235.0mm (9.25'') Height : 443.1mm (17.44'')

7. WEIGHT (with TILT/SWIVEL)

Net Weight : 9.0kg (19.84 lbs) Gross Weight : 12.3kg (27.12 lbs)

CONTENTS

- 2 -

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

PRECAUTION ......................................................... 3

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

OPERATING INSTRUCTIONS ................................ 4

WIRING DIAGRAM ................................................. 5

DISASSEMBLY ....................................................... 6

BLOCK DIAGRAM ................................................... 8

DESCRIPTION OF BLOCK DIAGRAM.....................9

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

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

PRINTED CIRCUIT BOARD................................... 13

EXPLODED VIEW...................................................14

REPLACEMENT PARTS LIST ............................... 16

PIN CONFIGURATION........................................... 20

SCHEMATIC DIAGRAM......................................... 28

PACKING AND ACCESSORIES ............................ 34

SPECIFICATIONS

MODE

POWER ON (NORMAL)

DPM

POWER OFF

SIGNAL

OFF

POWER CONSUMPTION

less than 50W less than 5 W

less than 5 W

LED COLOR

GREEN

ORANGE

OFF

VIDEO

ACTIVE

OFF

PRECAUTION

- 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 Gateway 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 turn off the power button or 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.

CAUTION

Please use only a plastic screwdriver to protect yourself from shock hazard during service operation.

CAUTION

• There is two backlight, and be careful of treatment it.

• MTBF (Mean Time Between Failure) of a backlight

is about 30,000 hours(mininum 20,000 hours).

Backlight Ass’y

(P/N: 6913TZZ002A)

IF BRIGHTNESS OF THE LCD MODULE DARKEN, REPLACE THE BACKLIGHT ONE OR ALL.

TIMING CHART

- 4 -

MODE

(Pixels)

(Lines)

Sync

Polarity

+ +

Dot Clock

108.0MHz

1280

1024

63.981KHz

60.02Hz

1688

1066

1280 48

1024 1

112408

42 3

248

Frequency

Total

Period

(A)

Video

Active

Time

(B)

Blanking

Time

(C)

Sync

Duration

(E)

Back

Porch

(F)

Front

Porch

(D)

Resolution

OPERATING INSTRUCTIONS

Power ON/OFF Button

This button is used to turn the monitor on and off.

Power Indicator

This indicator lights up green when the monitor operates normally; in DPMS (Energy Saving) mode, power off mode-its color changes to orange.

Brightness Control Buttons

Use these buttons for adjusting the brightness.

Front View

Rear View

DVI-D Signal Connectors

VIDEO

SYNC

WIRING DIAGRAM

- 5 -

CN2CN3

CN5

CN4

CN2

CN1

DISASSEMBLY

- 6 -

(a)

1. TILT/SWIVEL REMOVAL

1) Remove Hinge Cover. (Push the tilt cover both side).

2) Remove two screws (a).

3) Remove the Tilt/swivel.

2. FRONT CABINET REMOVAL

1) Remove two screws (a).

2) Release ten latches (b).

3) Remove the Front Cabinet.

3. INVERTER WIRE SHIELD & BACK COVER REMOVAL

1) Remove four screws (a).

2) Remove two Inverter Wire Shield.

3) Remove three screws (b).

4) Remove the Back Cover.

(a)

(b)

(a)

(b)

(a)

Front Cabinet

Back Cover

Inverter Wire Shield

- 7 -

4. INVERTER FRAME & REAR SHIELD REMOVAL

1) Remove sponge (a).

2) Remove two screws (b).

3) Remove the Inverter Frame.

4) Remove six screws (c).

5) Remove the Rear Frame.

(a)

(b)

(c)

5. MAIN TOTAL ASS’Y REMOVAL

1) Disconnect J1, J2, J3 and J4.

2) Remove five screws (a).

3) Remove two fixers (b).

4) Remove Aluminium Tape (c).

5) Disconnect FPC Cable, Module Connector and Control PCB Connector.

6) Remove Main Total Ass’y and Inverter PCB Ass’y.

6. MAIN PCB SHIELD REMOVAL

1) Disconnect J04.

2) Remove Inverter Ass’y from the Main PCB.

3) Release two latches (a).

4) Divide Top Shield, Main PCB, and Bottom Shield.

(b)

Rear Frame

Inverter Frame

FPC Cable

Control PCB Connector

Module Connector

PCB Shield

(Top)

Inverter Ass’y

Main PCB

J04

PCB Shield (Bottom)

(c)

(a)

BLOCK DIAGRAM

- 8 -

SiI161

Display

Data

Transmitter

LCD

Module

Form PSU

12V

DC/DC

Converter

Inverter

Data

Clock

Micro-Controller

12V

LVDS83

LG LCD PANEL

( LM181E3 )

. Brightness

3.3 V 3.3 V

5 V

MC68HC08

12V

5 V

3.3 V

LVDS Even

LVDS Odd

TMDS

Input Port

DVI-D

EEPROM

For

EDID

SDL-H

SDA-H

EEPROM

SDL SDA

DESCRIPTION OF BLOCK DIAGRAM

- 9 -

1. DC/DC Converter

This circuit supplies stand-by 5V(+5Vst) and regular 5V(+5V) for using LM2674 and LM2596S from AC/DC adapter (+12V). The +5V voltage supply to 3.3V voltage regulator.

2. Micro-Controller

This circuit consists of one EEPROM IC(24C02) which stores the control data for system and communicates DDC(Display Data Channel) and oscillator(X2). The operating procedures of Micro-Controller and its associated circuit are as follows;

1) The system controller detects frequency of vertical sync from Sil161A(U1) 47pin through AHC86(U10). The controller controls the power switching IC (SI4925) by the detection of vertical sync(H/V Sync).

2) The Micro-Controller controls the brightness of inverter by using the key control button and store the data to

EEPROM (24C02).

3. LVDS Circuit

LVDS transmitter (U2, U3) delivers digital signal to the receiver of module by the voltage swing of 1V. The peripheral circuitry of transmitter gets the DHS, DVS, DEN, DISPCLK signal, output LVDS signal. At the power down mode, MICOM lets the power down signal be low and shutdown pin be active low.

4. T.M.D.S Receiver

The Sil161A gets the T.M.D.S. video signal converted T.M.D.S. to 2 channel TTL level. The output 8-bit R, G, B, DHS, DVS and DE signal to the transmitter(U2, U3).

ADJUSTMENT

- 10 -

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

VGS

MONITOR

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

4.7K

74LS06

OFF ON

OFF

DVI-D Connector

Figure 1. Cable Connection

All adjustment are thoroughly checked and corrected when the monitor leaves the factory, but sometimes several minor adjustment may be required.

• Alignment appliances and tools.

- IBM compatible PC.

- Alignment Adapter and Software.

- DVI-D Connector.

- Install the cable for adjustment such as Figure 1and run the alignment program on the DOS for IBM compatible PC.

1. DDC Data Write Procedure

1) Use this procedure only when there is some problem on 24LC02(DDC support IC).

2) Select EEPROM -> Write EDID command and Enter.

3) This will write the EDID data to 24LC02.

TROUBLESHOOTING GUIDE

- 11 -

TROUBLE IN

U8, U5

CHECK

5VST VOLTAGE

(5V) ?

1. NO POWER

NO POWER

(POWER INDICATOR OFF

)

TROUBLE

SOMEWHERE ELSE

TROUBLE IN

ADAPTOR

CHECK J7

INPUT VOLTAGE

(12V) ?

TROUBLE IN

U4, U6

CHECK

+3.3V VOLTAGE ?

YES

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