AOC 212VA Schematic

22" LCD Color Monitor

AOC 212Va

Service

Service

Service

Horizontal Frequency

31.5 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………….………………….......6

3.Operation Instruction…………….................……...........7

3.1.General Instructions....................................…...........7

3.2.Control Button…………….…..............……...............7

3.3.OSD Menu…………….…...........................…............8

4.Input/Output Specification............……………............11

4.1.Input Signal Connector............……………...............11

4.2.Factory Preset Display Modes.................................12 4.3.Panel Specification.....………...…………..................13 5.Block Diagram…..…...................………..…................15 5.1.Software Flow Chart……………..…………....….......15 5.2.Electrical Block Diagram…………….………..….......17

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

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

6.2Power Board....……..............................................23

6.3Audio Board.............……....................................25 7.PCB Layout..………….......................................26 7.1.Main Board………..……........................................26 7.2.Power Board....……….........................................29

7.3Audio Board...............……....................................32 7.4.Key Board……………............................................32 8.Maintainability……….......................................33 8.1.Equipments and Tools Requirement......................33 8.2.Trouble Shooting………….....................................34 9.White-Balance, Luminance adjustment…….............40 10.Monitor Exploded View……….………….…............42 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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22" LCD Color Monitor

AOC 212Va

Revision List

Version	Release Date	Revision History	TPV Model Name
A00	May.10, 2007	Initial release	TC6MMADQWJAO8

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22" LCD Color Monitor

AOC 212Va

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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22" LCD Color Monitor				AOC 212Va
1. Monitor Specifications
		Model number		212Va
		Driving system		TFT Color LCD
		Size		559mm ( 22" 16:10)
	LCD Panel	Pixel pitch		0.282mm(H) x 0.282mm(V)
		Video		R, G, B Analog lnterface
		Separate Sync.		H/V TTL
		Display Color		16.7 million Colors
		Dot Clock		149MHz
		Horizontal scan range		31.5 kHz - 80 KHz
		Horizontal scan Size(Maximum)		473.76mm
		Vertical scan range		55 Hz - 75 Hz
		Vertical scan Size(Maximum)		296.1mm
		Optimal preset resolution		1680 x 1050 (60 Hz)
	Resolution	Highest preset resolution		1680 x 1050 (60 Hz)
		Plug & Play		VESA DDC2B
		Input Connector		D-Sub 15pin ,DVI 24 pin
		Input Video Signal		Analog / DVI-D
		Power Source		100~240VAC, 47~63Hz
		Power Consumption		Active < 49W
				Standby < 2W
		Connector Type		15-pin D-Sub,24 pin DVI
		Signal Cable Type		Detachable
		Dimensions & Weight:
	Physical	Height (with base)		428.32 mm
	Characteristics
		Width		505.20 mm
		Depth		210.82 mm
		Weight (monitor only)		6 kg
		Weight (with packaging)		8 kg
	Environmental	Temperature:
		Operating		0° to 40°
		Non-Operating		-20°to 60°
		Humidity:
				4

22" LCD Color Monitor				AOC 212Va
		Operating		10% to 85% (non-condensing)
		Non-Operating		5% to 80% (non-condensing)
		Altitude:
		Operating		0~ 3000m (0~ 10000 ft )
		Non-Operating		0~ 5000m (0~ 15000 ft )
	Regulations	CE/TCO03

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22" LCD Color Monitor

AOC 212Va

2. LCD Monitor Description

The LCD monitor will contain a main board, a power board, key board and 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.

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
AC-IN							Video signal, DDC
						HOST Computer
100V-240V

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22" LCD Color Monitor

AOC 212Va

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 the front of the panel of the monitor.

By changing these settings, the picture can be adjusted to your personal preferences.

-The power cord should be connected.

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

3.2Control Buttons

3.2.1 Key Control

3.2.2 Key Function

1. Auto Config		4. Menu
2.	- / Volume down	5. Source
3.	+ / Volume up	6. Power Button & Indicator

3.2.3 Attaching the Cables

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22" LCD Color Monitor

AOC 212Va

1.Power

2.Audio

3.DVI

4.Analog

Turn off your computer before performing the procedure below.

1.Connect the power cable to the AC port on the back of the monitor.

2.Connect one end of the 15-pin D-Sub cable to the back of the monitor and connect the other end to the computer's D-Sub port.

3.(Optional - Requires a video card with DVI port) - Connect one end of the 24-pin DVI cable to the back of the monitor and connect the other end to the computer's DVI port

4.Turn on your monitor and computer.

OSD Settings

•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-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.

•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.

•Press Auto key continually for 7 sec. to turn on or off DDC-CI.

3.3 OSD Menu

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22" LCD Color Monitor						AOC 212Va
Function Control Illustration
		Luminance	Adjust Range			Description
		Brightness	0-100			Backlight Adjustment
		Contrast	0-100			Contrast from Digital-register.
			Standard			Standard Mode
		Eco mode	Text			Text Mode
			Internet			Internet Mode
			Game			Game Mode
			Movie			Movie Mode
			Sports			Sports Mode
			Gamma1			Adjust to Gamma1
		Gamma
			Gamma2			Adjust to Gamma 2
			Gamma3			Adjust to Gamma 3
		DCR	Off			Disable dynamic contrast ratio
			On			Enable dynamic contrast ratio
		Image Setup
		Clock	0-100			Adjust picture Clock to reduce Vertical-Line
						noise.
		Focus	0-100			Adjust Picture Phase to reduce Horizontal-Line
						noise
		H.Position	0-100			Adjust the vertical position of the picture.
		V.Position	0-100			Adjust the horizontal position of the picture.
		Color Temp.
		Warm				Recall Warm Color Temperature from EEPROM.
		Normal				Recall Normal Color Temperature from
						EEPROM.
		Cool				Recall Cool Color Temperature from EEPROM.
		sRGB				Recall SRGB Color Temperature from EEPROM.
			User-B			Blue Gain from Digital-register
			User-G			Green Gain Digital-register.
		User	User-R			Red Gain from Digital-register
			User-Y			Yellow Gain from Digital-register
			User-C			Cyan Gain from Digital-register
			User-M			Magenta Gain from Digital-register
					9

22" LCD Color Monitor							AOC 212Va
		Color Boost
		Full Enhance		on or off		Disable or Enable Full Enhance Mode
		Nature Skin		on or off		Disable or Enable Nature Skin Mode
		Green Field		on or off		Disable or Enable Green Field Mode
		Sky-blue		on or off		Disable or Enable Sky-blue Mode
		AutoDetect		on or off		Disable or Enable AutoDetect Mode
		Demo		on or off		Disable or Enable Demo
		Picture Boost
		Frame Size	0-100			Adjust Frame Size
		Brightness	0-100			Adjust Frame Brightness
		Contrast	0-100			Adjust Frame Contrast
		Hue	0-100			Adjust Frame Hue
		Saturation	0-100			Adjust Frame Saturation
		Position		H. position		Adjust Frame horizontal Position
				V.position		Adjust Frame vertical Position
		Bright Frame		on or off		Disable or Enable Bright Frame
		OSD Setup
		H.Position	0-100			Adjust the vertical position of OSD
		V.Position	0-100			Adjust the horizontal position of OSD
		Timeout	0-100			Adjust the OSD Timeout
		Language				Select the OSD language
		Extra
		Input Select		Digital		Select Digital Signal Source as Input
				Analog		Select Analog Signal Source as Input
		Auto Config		yes or no		Auto adjust the picture to default
		Reset		yes or no		Reset the menu to default
		DDC-CI				Turn ON/OFF DDC-CI Support
		Information				Show the information of the main image and
						sub-image source
LED Indicators
	Status			LED Color
	Full Power Mode			Green
	Active-off Mode			Orange
					10

22" LCD Color Monitor														AOC 212Va
4. Input/Output Specification
4.1 Input Signal Connector
		Pin No.			Description					Pin No.		Description
		1.			Video-Red					9.				+5V
		2.			Video-Green					10.		Detect Cable
		3.			Video-Blue					11.				NC
		4.			NC					12.		DDC-Serial Data
		5.			GND					13.			H-Sync
		6.			GND-R					14.			V-Sync
		7.			GND-G					15.		DDC-Serial clock
		8.			GND-B
								VGA connector layout
		Pin No.		Signal Name				Pin No.		Signal Name		Pin No.		Signal Name
	1		TMDS Data 2-					9	TMDS Data 1-			17		TMDS Data 0-
	2		TMDS Data 2+					10	TMDS Data 1+			18		TMDS Data 0+
	3		TMDS Data 2/4 Shield					11	TMDS Data 1/3 Shield			19		TMDS Data 0/5 Shield
	4		TMDS Data 4-					12	TMDS Data 3-			20		TMDS Data 5-
	5		TMDS Data 4+					13	TMDS Data 3+			21		TMDS Data 5+
	6		DDC Clock					14	+5V Power			22		TMDS Clock Shield
	7		DDC Data					15	Ground(for+5V)			23		TMDS Clock +
	8		N.C.					16	Hot Plug Detect			24		TMDS Clock -
								DVI connector layout
									11

22" LCD Color Monitor					AOC 212Va
4.2 Factory Preset Display Modes
				Horizontal	Vertical
	Stand	Resolution
				Frequency(KHz)	Frequency(Hz)
	Dos-mode	720 x 400		31.47	70.0
	VGA	640 x 480		31.47	60.0
	VGA	640 x 480		37.50	75.0
	SVGA	800 x 600		37.879	60.0
	SVGA	800 x 600		46.875	75.0
	XGA	1024 x 768		48.363	60.0
	XGA	1024 x 768		56.476	70.0
	XGA	1024 x 768		60.02	75.0
	XGA	1024 x 768		48.780	60.0
	XGA	1024 x 768		60.241	75.0
	SXGA	1280 x 1024		64.00	60.0
	SXGA	1280 x 1024		80.00	75.0
	WSXGA	1680 x 1050		65.29	60.0
	UXGA	1600 x 1200		37.50	60.0

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22" LCD Color Monitor	AOC 212Va
4.3 Panel Specification
4.3.1 General Features

The M220Z1-L01 model is a 22 inch wide TFT-LCD module with a 4-CCFL Backlight Unit and a 30-pin 2ch-LVDS interface. This module supports 1680 x 1050 WSXGA+ (16:10 wide screen) mode and displays up to 16.7 millions colors. The inverter module for the Backlight Unit is not built in.

4.3.2 Features

4.3.3 Display Characteristics

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22" LCD Color Monitor

AOC 212Va

4.3.4 Optical Characteristics

4.3.5Electrical Characteristics

(1)TFTLCD

(2) Backlight

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22" LCD Color Monitor

AOC 212Va

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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22" LCD Color Monitor

AOC 212Va

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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22" LCD Color Monitor	AOC 212Va
5.2 Electrical Block Diagram
5.2.1 Main Board

Panel Interface

(CN101)

Flash Memory

PM25LV010-25 SCE (U402)

SDA

SCL

EEPROM 24LC16B/SNG (U403)

Scalar TSUMU58WHJ-LF		Key Control
(Include MCU, ADC, OSD)		Interface
(U401)		(CN403)

Crystal 14.318MHZ

(X401)

	H sync						Digital Video
	V sync
							Signal
	RGB
	D-Sub						DVI
	Connector					Connector
	(CN405)						(CN406)
	DDCA_SDA,						DDCD_SDA,
	DDCA_SCL						DDCD_SCL
	EEPROM						EEPROM
	M24C02						M24C02
	(U404)						(U405)

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22" LCD Color Monitor

AOC 212Va

5.2.2 Inverter/Power Board

AC input

Bridge

Rectifier

Transformer

EMI filter

Rectifier

diodes

and Filter

Start Circuit: R904, R932, R933

CN902

12V

Feedback

PWM

Circuit

Control IC

5V

ON/OFF

Output

MOSFET

Circuit

Transformer

Lamp

Feedback

Over

ON/OFF

PWM

Circuit

Voltage

Control

Control IC

DIM

DIM

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