AOC 912VWA, 1912VWA Schematic

19" Wide LCD Color Monitor AOC 1912VWA

Service

Horizontal Frequency

30 kHz-80 kHz

TABLE OF CONTENTS

Description Page Description Page

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

Revision List.…........................………................……......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...........................…............8

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…….…................……………...............15

5.1 Software Flow Chart…………………………….........15

5.2 Electrical Block Diagram…………………...…......17

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.

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

6. Schematic……………..............................….....19

6.1 Main Board…………..............................................19

6.2 Power Board....……………....................................24

6.3 Key Board ……………………………..…………….26

6.4 Audio Board....……................................................27

7. PCB Layout..………….......................................28

7.1 Main Board……………......................................28

7.2 Power Board…......................................................31

7.3 Audio Board....…….......................................33

7.4 Keypad Board……….....................................33

8. Maintainability……….......................................34

8.1. Equipments and Tools Requirement.....................34

8.2. Trouble Shooting…………....................................35

9. White-Balance, Luminance adjustment...................41

10.Monitor Exploded View……..……………............42

11.BOM List....…….....................................................43

19" Wide LCD Color Monitor AOC 1912VWA

Revision List

Revision Date Revision History TPV Model

A00 Dec-27-2006 Initial release T96HNNNQWCAO8P

19" Wide LCD Color Monitor AOC 1912VWA

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.)

19" Wide LCD Color Monitor AOC 1912VWA

1. Monitor Specifications

Driving system TFT Color LCD

LCD Panel

Input

Display Colors 16.2M Colors

Dot Clock 135MHz

Max. Resolution 1440 × 900 @60Hz

Plug & Play VESA DDC2B

EPA ENERGY STAR®

Input Connector 15-pin D-Sub

Input Video Signal

Maximum Screen Size

Size 48cm(19.0")

Pixel pitch 0.2835mm( H ) × 0.2835mm( V )

Video R,G,B Analog Interface

Separate Sync. H/V TTL

H-Frequency 30kHz – 80kHz

V-Frequency 55-75Hz

ON Mode ≤36W

OFF Mode ≤1W

Analog:0.7Vp-p(standard), 75 OHM, Positive

Horizontal : 408.24mm Vertical : 255.15mm

Power Source 100~240VAC,50~60Hz

Environmental Considerations

Dimension 425 (W)×418 (H)×207 (D)mm

Weight (N. W.) 5.9kg Unit (net)

Power Consumption( Maximum ) 36 Watts

Audio Output Rated Power 1.5 W rms (Per channel)

Regulatory Compliance FCC，UL，CUL, TUV-S

Operating Temp: 5° to 50°C Storage Temp.: -20° to 60°C Operating Humidity: 10% to 85%

19" Wide LCD Color Monitor AOC 1912VWA

2. LCD Monitor Description

The LCD MONITOR will contain a main board, a power board, an audio board and a key 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.

Power board

(Include: adapter, inverter)

AC-IN 100V-240V

CCFL Drive.

Monitor Block Diagram

Flat Panel and CCFL backlight

Main board

Audio board

Key board

HOST Computer

RS232 Connector

For white balance

adjustment in factory

mode

Video signal, DDC

19" Wide LCD Color Monitor AOC 1912VWA

3. Operating Instructions

3.1 General Instructions

Press the power button to turn the monitor on or off. The control buttons are located in the front 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 Buttons

EXTERNAL CONTROLS

Auto Adjust Key/Exit 4. > / Volume

< / Volume 5. MENU/ENTER

Power Key/ LED

19" Wide LCD Color Monitor AOC 1912VWA

FRONT PANEL CONTROL

• Power Button / Power Indicator:

Press this button to turn the monitor ON or OFF.

Green — Power On mode.

Orange — Off mode.

• MENU / ENTER:

Activate OSD menu when OSD is OFF or activate/de-activate adjustment function when OSD is ON or Exit OSD

menu when in Volume Adjust OSD status.

• > /Volume:

Activates the volume control when the OSD is OFF or navigate through adjustment icons when OSD is ON or

adjust a function when function is activated.

• < /Volume:

Activates the volume control when the OSD is OFF or navigate through adjustment icons when OSD is ON or

adjust a function when function is activated.

• Auto Adjust button / Exit:

1. When OSD menu is in active status, this button will act as EXIT-KEY (EXIT OSD menu).

2. When OSD menu is in off status, press this button for 2 seconds to activate the Auto Adjustment function.

The Auto Adjustment function is used to set the HPos, VPos, Clock and Focus.

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.

NOTES

• Do not install the monitor in a location near heat sources such as radiators or air ducts, or in a place subject to

direct sunlight, or excessive dust or mechanical vibration or shock.

• Save the original shipping carton and packing materials, as they will come in handy if you ever have to ship your

monitor.

• For maximum protection, repackage your monitor as it was originally packed at the factory.

• To maintain the cleanness of your LCD display, wipe it periodically with clean and soft cloth. The screen may be

damaged by any liquid splash.

• To keep the monitor looking new, periodically clean it with a soft cloth. Stubborn stains may be removed with a

cloth lightly dampened with a mild detergent solution. Never use strong solvents such as thinner, benzene, or

abrasive cleaners, since these will damage the cabinet. As a safety precaution, always unplug the monitor before

cleaning it.

19" Wide LCD Color Monitor AOC 1912VWA

3.3 Adjusting the Picture

Adjustment steps:

1. Press the MENU-button to activate the OSD window.

2. Press < or > to navigate through the functions. Once the desired function is highlighted, press the MENU-button

to 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.

3. Press < or > to change the settings of the selected function.

4. To exit and save, select the exit function. If you want to adjust any other function, repeat steps 2-3.

Main

Item

Luminance

Image Setup

Image

Position

Main

Icon

The OSD Message

Sub

Item

Contrast

Brightness

Focus

Clock

H. Position

V. Position

Warm N/A Recall Warm Color Temperature from EEPROM.

Cool N/A Recall Cool Color Temperature from EEPROM.

Sub Menu Icon

Description

Contrast from Digital-register.

Backlight Adjustment

Adjust Picture Phase to reduce Horizontal-Line noise

Adjust picture Clock to reduce Vertical-Line noise.

Adjust the horizontal position of the picture.

Adjust the vertical position of the picture.

sRGB N/A Recall sRGB Temperature from EEPROM.

Color Temp.

User / Red

User / Green

User / Blue

Red Gain from Digital-register.

Green Gain Digital-register.

Blue Gain from Digital-register.

19" Wide LCD Color Monitor AOC 1912VWA

Main

Item

Main Menu

Icon

Sub

Item

Sub Menu Icon Description

Input Select

OSD Setup

Language

Information

Reset

Analog N/A

Digital N/A Select input signal from digital source (DVI).

H. Position

V. Position

OSD Timeout

Language

Information N/A

Yes N/A Clear each old status of Auto-configuration.

No N/A Do not execute reset, return to main menu.

N/A

Select input signal from analog source (D-Sub).

Adjust the horizontal position of the OSD.

Adjust the vertical position of the OSD.

Adjust the OSD timeout.

Set OSD language

Show the resolution, H/V frequency and input port of current input timing.

Exit

N/A N/A Exit OSD

19" Wide LCD Color Monitor AOC 1912VWA

4. Input/Output Specification

4.1 Input Signal Connector

Pin No.

1. Red 9. +5V

2. Green 10. Detect Cable

3. Blue 11. Ground

4. Ground 12. DDC-Serial Data

5. Ground 13. H-Sync

6. R-Ground 14. V-Sync

7. G-Ground 15. DDC-Serial Clock

8. B-Ground

Description Pin No. Description

15 - Pin Color Display Signal Cable

11 15

Pin No. Description Pin No. Description

1. TMDS Data 2- 13. TMDS Data 3+

2. TMDS Data 2+ 14. +5V Power

3. TMDS Data 2/4 Shield 15. Ground(for+5V)

4. TMDS Data 4- 16. Hot Plug Detect

5. TMDS Data 4+ 17. TMDS Data 0-

6. DDC Clock 18. TMDS Data 0+

7. DDC Data 19. TMDS Data 0/5 Shield

8. N.C. 20. TMDS Data 5-

9. TMDS Data 1- 21. TMDS Data 5+

10. TMDS Data 1+ 22. TMDS Clock Shield

11. TMDS Data 1/3 Shield 23. TMDS Clock +

12. TMDS Data 3- 24. TMDS Clock -

24 - Pin Color Display Signal Cable

19" Wide LCD Color Monitor AOC 1912VWA

4.2 Factory Preset Display Modes

Standard

Dos-mode 720 x 400

VGA

SVGA

XGA

SXGA

WXGA+ 1440×900 55.935 kHz 60.0 Hz

Resolution

640 × 480 31.47kHz 60.0Hz

640 × 480 37.50kHz 75.0Hz

800 × 600 37.879kHz 60.0Hz

800 × 600 46.875kHz 75.0Hz

1024 × 768 48.363kHz 60.0Hz

1024 × 768 56.476kHz 70.0Hz

1024 × 768 60.021kHz 75.0Hz

1280 × 1024 64.000kHz 60.0Hz

1280 × 1024 80.000kHz 75.0Hz

Horizontal Frequency

31.47kHz 70.0Hz

Vertical

Frequency

19" Wide LCD Color Monitor AOC 1912VWA

4.3 Panel Specification

HannStar Display model HSD190MGW1-A00 is a color active matrix thin film transistor (TFT) liquid crystal display

(LCD) that uses amorphous silicon TFT as a switching device. This model is composed of a TFT LCD panel, the

voltage reference, common voltage, DC-DC converter, column, and row driver circuit. This TFT LCD has a 19-inch

diagonally measured active display area with WXGA+ resolution (900 vertical by 1440 horizontal pixel array).

4.3.1 Display Characteristics

19" Wide LCD Color Monitor AOC 1912VWA

4.3.2 Optical Characteristics

19" Wide LCD Color Monitor AOC 1912VWA

4.3.3 Parameter guide line for CCFL Inverter

TFT LCD Module:

Back Light Unit:

19" Wide LCD Color Monitor AOC 1912VWA

5. Block Diagram

5.1 Software Flow Chat

19" Wide LCD Color Monitor AOC 1912VWA

1) MCU initialize.

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

disappear.

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?

19" Wide LCD Color Monitor AOC 1912VWA

(

5.2 Electric Block Diagram

5.2.1 Main Board

Keypad Interface

(CN403)

SDA SCL

EEPROM

AT24C16AN-10SU-2.7

U403)

Crystal 12MHz

Panel Interface

NT68663MEFG

(Include MCU, ADC, OSD)

RXD

RGB

TXD

D-Sub Connector

(CN405)

DB15_SDA DB15_SCL

EEPROM M24C02

U405)

H-SYNC V-SYNC

+ 38 hidden pages