AOC 912VWA, 1912VWA Schematic

19" Wide LCD Color Monitor

AOC 1912VWA

Service

Service

Service

							Horizontal Frequency
		TABLE OF CONTENTS					30 kHz-80 kHz
Description		Page			Description		Page
	Table Of Contents.......…….................……...........…........1				6.	Schematic……………..............................….....19
	Revision List.…........................………................……......2				6.1 Main Board…………..............................................19
	Important Safety Notice.………….…..................……......3				6.2 Power Board....……………....................................24
	1. Monitor Specification.................................………........4				6.3 Key Board ……………………………..…………….26
	2. LCD Monitor Description…………………………….......5				6.4 Audio Board....……................................................27
	3. Operation	Instruction…………...................…...........6			7. PCB Layout..………….......................................28
	3.1 General Instructions.....................................…...........6				7.1	Main Board……………......................................28
	3.2 Control Button……………………………..……...........6				7.2 Power Board…......................................................31
	3.3 Adjusting the Picture...........................…............8				7.3 Audio Board....…….......................................33
	4. Input/Output Specification............……………............10				7.4	Keypad	Board……….....................................33
	4.1 Input Signal Connector............…..……................10				8.	Maintainability……….......................................34
	4.2 Factory Preset Display Modes.........................11				8.1. Equipments and Tools Requirement.....................34
	4.3 Panel Specification.....………………........................12				8.2. Trouble Shooting…………....................................35
	5.Block Diagram…….…................……………...............15				9. White-Balance, Luminance adjustment...................41
	5.1 Software Flow Chart…………………………….........15				10.Monitor Exploded View……..……………............42
	5.2 Electrical	Block Diagram…………………...…......17			11.BOM List....…….....................................................43

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

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19" Wide LCD Color Monitor							AOC 1912VWA
				Revision List
	Revision	Date		Revision History			TPV Model
	A00	Dec-27-2006		Initial release			T96HNNNQWCAO8P

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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.)

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19" Wide LCD Color Monitor				AOC 1912VWA
1. Monitor Specifications
		Driving system		TFT Color LCD
	LCD Panel
		Size		48cm(19.0")
		Pixel pitch		0.2835mm( H ) × 0.2835mm( V )
		Video		R,G,B Analog Interface
	Input	Separate Sync.		H/V TTL
		H-Frequency		30kHz – 80kHz
		V-Frequency		55-75Hz
	Display Colors			16.2M Colors
	Dot Clock			135MHz
	Max. Resolution			1440 × 900 @60Hz
	Plug & Play			VESA DDC2BTM
	EPA ENERGY STAR®	ON Mode		≤36W
		OFF Mode		≤1W
	Input Connector			15-pin D-Sub
	Input Video Signal			Analog:0.7Vp-p(standard),
				75 OHM, Positive
	Maximum Screen Size			Horizontal : 408.24mm
				Vertical : 255.15mm
	Power Source			100~240VAC,50~60Hz
	Environmental			Operating Temp: 5° to 50°C
				Storage Temp.: -20° to 60°C
	Considerations
				Operating Humidity: 10% to 85%
	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

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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.

Monitor Block Diagram

CCFL Drive.

Flat Panel and

CCFL backlight

RS232 Connector

Power board

Main board

For white balance

(Include: adapter, inverter)

adjustment in factory

mode

Audio board

Key board

Video signal, DDC

AC-IN

100V-240V

HOST Computer

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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.

3.2Control Buttons

EXTERNAL CONTROLS

1.	Auto Adjust Key/Exit	4.	> / Volume
2.	< / Volume	5.	MENU/ENTER
3.	Power Key/ LED

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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.

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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.

							The OSD Message
Main		Main		Sub	Sub Menu
Menu		Menu		Menu					Description
					Icon
Item		Icon		Item
Luminance				Contrast					Contrast from Digital-register.
				Brightness					Backlight Adjustment
Image Setup				Focus					Adjust Picture Phase to reduce Horizontal-Line noise
				Clock					Adjust picture Clock to reduce Vertical-Line noise.
Image				H. Position					Adjust the horizontal position of the picture.
Position				V. Position					Adjust the vertical position of the picture.
				Warm		N/A			Recall Warm Color Temperature from EEPROM.
				Cool		N/A			Recall Cool Color Temperature from EEPROM.
Color Temp.				sRGB		N/A			Recall sRGB Temperature from EEPROM.
				User / Red					Red Gain from Digital-register.
				User / Green					Green Gain Digital-register.
				User / Blue					Blue Gain from Digital-register.

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19" Wide LCD Color Monitor

AOC 1912VWA

	Main	Main Menu			Sub
	Menu				Menu	Sub Menu Icon
			Icon
	Item				Item
	Input Select				Analog		N/A
					Digital		N/A
					H. Position
	OSD Setup
					V. Position
					OSD Timeout
	Language				Language		N/A
	Information				Information		N/A
	Reset				Yes		N/A
					No		N/A
	Exit				N/A		N/A

Description

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

Select input signal from digital source (DVI).

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.

Clear each old status of Auto-configuration. Do not execute reset, return to main menu. Exit OSD

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19" Wide LCD Color Monitor						AOC 1912VWA
4. Input/Output Specification
4.1 Input Signal Connector
	Pin No.	Description	Pin No.			Description
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

15 - Pin Color Display Signal Cable

1	5
6	10
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

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19" Wide LCD Color Monitor							AOC 1912VWA
4.2 Factory Preset Display Modes
	Standard	Resolution				Horizontal	Vertical
						Frequency	Frequency
	Dos-mode	720 x 400				31.47kHz	70.0Hz
	VGA	640 × 480				31.47kHz	60.0Hz
		640 × 480				37.50kHz	75.0Hz
	SVGA	800	× 600			37.879kHz	60.0Hz
		800	× 600			46.875kHz	75.0Hz
		1024 × 768				48.363kHz	60.0Hz
	XGA
		1024 × 768				56.476kHz	70.0Hz
		1024 × 768				60.021kHz	75.0Hz
	SXGA	1280	× 1024			64.000kHz	60.0Hz
		1280	× 1024			80.000kHz	75.0Hz
	WXGA+	1440×900				55.935 kHz	60.0 Hz

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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

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19" Wide LCD Color Monitor

AOC 1912VWA

4.3.2 Optical Characteristics

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19" Wide LCD Color Monitor

AOC 1912VWA

4.3.3 Parameter guide line for CCFL Inverter

TFT LCD Module:

Back Light Unit:

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19" Wide LCD Color Monitor

AOC 1912VWA

5. Block Diagram

5.1 Software Flow Chat

1

2	Y	3

N

4

5 N

Y

6

7	N	8

Y

9

	10	N	11
	Y
N	12		13	N
	Y		Y
	14		15	N	16
			Y
			17

18	N	19

Y

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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?

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19" Wide LCD Color Monitor

AOC 1912VWA

5.2 Electric Block Diagram

5.2.1 Main Board

Panel Interface

(CN406)

Keypad Interface		NT68663MEFG
(CN403)
		(Include MCU, ADC, OSD)
		(U401)

SDA

SCL RXD RGB H-SYNC

TXD V-SYNC

EEPROM
		Crystal 12MHz
					D-Sub Connector
AT24C16AN-10SU-2.7
		(X401)
(U403)					(CN405)
					DB15_SDA
					DB15_SCL
					EEPROM M24C02
					(U405)

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