AOC 203Vwa Schematic

20” LCD Color Monitor AOC 203Vwa

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Table Of Contents.......……...................…............…........1

Revision Li st.…........................................……......2

Important Safety Notice.……..………...............……......3

1. Monitor Specification......….......................………........4

2. LCD Monitor Description……………...…………….......5

3. Operation Instruction……………...............……...........6

3.1 General Instructions……….........................…...........6

3.2 Control Button…….………….…..............……............6

3.3 Adjusting the Picture.................……..........…............7

4. Input/Output Specification..........……………...........10

4.1 Input Signal Connector..........……………................10

4.2 Factory Preset Display Modes....……......................11

4.3 Panel Specification.....…………….…..............……..12

5. Block Diagram……..…................…………................14

5.1 Software Flow Chart………….……………....……....14

5.2 Electrical Block Diagram…………………..….......16

6.Schematic…………….............................................…18

6.1 Main Board.…..…...……..........................................18

6.2 Power Board....………..……....................................22

6.3 Audio Board……………………………………………24

7.PCB Layout..………….......................................25

7.1 Main Board………………........................................25

7.2 Power Board…………...….......................................28

7.3 Key Board……………..…….....................................29

7.4 Audio Board…………..…….....................................30

8. Maintainability……........................….........……......33

8.1 Equipments and Tools Requirement.....………........33

8.2 Trouble Shooting…………..……..............................33

9. White-Balance, Luminance adjustment..……............37

10. Monitor Exploded View………………………............39

11. BOM list………….....................................................41

CAUTION: USE A SEPARATE ISOLATION TRANSFOMER FOR THIS UNIT WHEN SERVICING

Service

Horizontal Frequency

31kHz – 82kHz

TABLE OF CONTENTS

Description Page Description Page

N

SAFETY NOTICE

ANY PERSON ATTEMPTING TO SERVICE THIS CHASSIS MUST FAMILIARIZE HIMSELF WITH THE CHASSIS AND BE AWARE OF THE NECESSARY SAFETY PRECAUTIONS TO BE USED WHEN SERVICING ELECTRONIC EQUIPMENT CONTAINING HIGH VOLTAGES.

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Revision

Date

Revision History

TPV Model

A00

Oct.-15-07

Initial Release

TA7CNADQW3AC6N

Revision List

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Important Safety Notice

Proper service and repair is important to the safe, reliable operation of all AOC Company Equipment. The service procedures recommended by AOC and described in this service manual are effective methods of performing service operations. Some of these service operations require the use of tools specially designed for the purpose. The special tools should be used when and as recommended.

It is important to note that this manual contains various CAUTIONS and NOTICES which should be carefully read in order to minimize the risk of personal injury to service personnel. The possibility exists that improper service methods may damage the equipment. It is also important to understand that these CAUTIONS and NOTICES ARE NOT EXHAUSTIVE. AOC could not possibly know, evaluate and advise the service trade of all conceivable ways in which service might be done or of the possible hazardous consequences of each way. Consequently, AOC has not undertaken any such broad evaluation. Accordingly, a servicer who uses a service procedure or tool which is not recommended by AOC must first satisfy himself thoroughly that neither his safety nor the safe operation of the equipment will be jeopardized by the service method selected. Hereafter throughout this manual, AOC Company will be referred to as AOC.

WARNING

Use of substitute replacement parts, which do not have the same, specified safety characteristics may create shock, fire, or other hazards.

Under no circumstances should the original design be modified or altered without written permission from AOC. AOC assumes no liability, express or implied, arising out of any unauthorized modification of design. Servicer assumes all liability.

FOR PRODUCTS CONTAINING LASER: DANGER-Invisible laser radiation when open AVOID DIRECT EXPOSURE TO BEAM. CAUTION-Use of controls or adjustments or performance of procedures other than those specified herein may result in hazardous radiation exposure. CAUTION -The use of optical instruments with this product will increase eye hazard.

TO ENSURE THE CONTINUED RELIABILITY OF THIS PRODUCT, USE ONLY ORIGINAL MANUFACTURER'S REPLACEMENT PARTS, WHICH ARE LISTED WITH THEIR PART NUMBERS IN THE PARTS LIST SECTION OF THIS SERVICE MANUAL. 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 is grounded through wristband.

-Do not leave the module in high temperature and in areas of high humidity for a long time.

-Avoid contact with water as it may a short circuit within the module.

-If the surface of panel becomes dirty, please wipe it off with a soft material. (Cleaning with a dirty or rough cloth may damage the panel.)

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1. Monitor Specifications

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Monitor Block Diagram

HOST Computer

AC-IN 100V-240V

Power board (Include: adapter, inverter)

Flat Panel and CCFL backlight

Main Board

RS232 Connector For white balance adjustment in factory mode

CCFL Drive.

Video signal,

Key board

Audio board

2. LCD Monitor Description

The LCD MONITOR will contain a main board, a power board, a key board and an audio board which house the flat panel control logic, brightness control logic and DDC. The power board will provide AC to DC Inverter voltage to drive the backlight of panel and the main board chips each voltage.

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3. Operating Instructions

3.1 General Instructions

Press the power button to turn the monitor on or off. The other control buttons are located at front panel of the monitor. By changing these settings, the picture can be adjusted to your personal preferences.

The power cord should be connected.

-

Connect the video cable from the monitor to the video card.

-

Press the power button to turn on the monitor, the power indicator will light up.

-

3.2 Control Button

External Controls

1. Auto Config

2. Volume / +

3. Volume / -

4. Menu / Enter

5. Power Button & Indicator

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3.3 Adjusting The Picture

 Press the MENU-button to activate the OSD window.  Press >/+ or </- to navigate through the functions. Once the desired function is highlighted, press the MENU-buttonto

activate it.If the function selected has a sub-menu, press or again to navigate through the sub-menu functions. Once the desired function is highlighted, press MENU-button to activate it.

 Press>/+ or </- to change the settings of the selected function. To exit and save, select the exit function. If you want to

adjust any other function, repeat steps 2-3.

 OSD Lock Function: To lock the OSD, press and hold the MENU button while the monitor is off and then press power

button to turn the monitor on. To un-lock the OSD - press and hold the MENU button while the monitor is off and then press power button to turn the monitor on.

 Eco Mode hot key : Press the Eco key continuously to select the Eco mode of brightness when there is no OSD ( Eco

mode hot key may not be available in all models).

 Volume adjustment hot key : Press Volume / - or Volume /+ to adjust volume when there is no OSD ( Only for the

models with speakers)

 Press Exit key continually for 7 sec. to turn on or off DDC-CI.

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4. Input/Output Specification

4.1 Input Signal Connector

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4.2 Factory Preset Display Modes

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4.3 Panel Specification

4.3.1 Features

CLAA201WA04 is 20.1”(51.11cm) color TFT-LCD (Thin Film Transistor Liquid Crystal Display)module composed of LCD panel, LVDS driver ICs, control circuit and backlight(CCFL, 4 tubes). By applying 8 bit digital data(6bits+Hi-FRC), 1680×1050, drived by 5 voltages,16.7M-color images are is played on the 20.1” diagonal screen. The module structure is fixed by iron frame, without the inverter or the backlight. Interface of data and control signals is typ.

4.3.2 Display Characteristics

The following items are characteristics summary on the table under 25 ℃ condition:

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4.3.3 Optical Characteristics

The optical characteristics are measured under stable conditions at Ta=25℃，VCC=5.0V

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1

2

N

Y

5

Y

N

10

Y

N

12

Y

N 7 Y

N 6 4

3

9

14

11

13

Y

N

15

Y

N

16

17

19

Y

N

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5. Block Diagram

5.1 Software Flow Chart

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1) MCU initializes.

2) Is the EPROM blank?

3) Program the EPROM by default values.

4) Get the PWM value of brightness from EPROM.

5) Is the power key pressed?

6) Clear all global flags.

7) Are the AUTO and SELECT keys pressed?

8) Enter factory mode.

9) Save the power key status into EPROM. Turn on the LED and set it to green color. Scalar initializes.

10) In standby mode?

11) Update the lifetime of back light.

12) Check the analog port, are there any signals coming?

13) Does the scalar send out an interrupt request?

14) Wake up the scalar.

15) Are there any signals coming from analog port?

16) Display "No connection Check Signal Cable" message. And go into standby mode after the message

disappears.

17) Program the scalar to be able to show the coming mode.

18) Process the OSD display.

19) Read the keyboard. Is the power key pressed?

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Scalar IC TSUMU58WHJ

(Include MCU, ADC, OSD)

(U203)

EEPROM

24LC16B/SNG

(U204)

H sync V sync

RGB

LCD Interface

(CN402)

Crystal

14.318MHZ (X201)

D-Sub

Connector

(CN101)

DVI

Connector

(CN102)

Digital

Video

Signal

5.2 Electrical Block Diagram

5.2.1 Main Board