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
6.1 Main Board…….....................................................19
6.2 Power Board....……..............................................23
6.3 Audio Board.............……....................................25
7.PCB Layout..………….......................................26
7.1.Main Board………..……........................................26
7.2.Power Board....……….........................................29
7.3 Audio 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)
Pixel pitch 0.282mm(H) x 0.282mm(V)
LCD Panel
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
Resolution
Physical
Characteristics
Vertical scan Size(Maximum) 296.1mm
Optimal preset resolution 1680 x 1050 (60 Hz)
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
Connector Type 15-pin D-Sub,24 pin DVI
Signal Cable Type Detachable
Dimensions & Weight:
Height (with base)
Width
Active < 49W
Standby < 2W
428.32 mm
505.20 mm
Environmental
Depth
Weight (monitor only)
Weight (with packaging)
Temperature:
Operating 0° to 40°
Non-Operating -20°to 60°
Humidity:
210.82 mm
6 kg
8 kg
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22" LCD Color Monitor AOC 212Va
Operating 10% to 85% (non-condensing)
Non-Operating 5% to 80% (non-condensing)
Regulations
Altitude:
Operating 0~ 3000m (0~ 10000 ft )
Non-Operating 0~ 5000m (0~ 15000 ft )
CE/TCO03
5
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.
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
Video signal, DDC
HOST Computer
RS232 Connector
For white balance
adjustment in factory
mode
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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.
-
3.2 Control 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
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.
4. Analog
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
Gamma
DCR
Image Setup
Clock 0-100
Focus 0-100
Text Text Mode
Internet Internet Mode
Game Game Mode
Movie Movie Mode
Sports Sports Mode
Gamma1 Adjust to Gamma1
Gamma2 Adjust to Gamma 2
Gamma3 Adjust to Gamma 3
Off Disable dynamic contrast ratio
On Enable dynamic contrast ratio
Adjust picture Clock to reduce Vertical-Line
noise.
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
Normal
Cool
sRGB
User
User-B Blue Gain from Digital-register
User-G Green Gain Digital-register.
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
Recall Warm Color Temperature from EEPROM.
Recall Normal Color Temperature from
EEPROM.
Recall Cool Color Temperature from EEPROM.
Recall SRGB Color Temperature from EEPROM.
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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
Extra
Input Select
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
Digital Select Digital Signal Source as Input
Analog Select Analog Signal Source as Input
Select the OSD language
Show the information of the main image and
sub-image source
LED Indicators
Status LED Color
Full Power Mode Green
Active-off Mode Orange
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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
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22" LCD Color Monitor AOC 212Va
4.2 Factory Preset Display Modes
Horizontal
Stand Resolution
Frequency(KHz)
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
Vertical
Frequency(Hz)
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
4.3.5 Electrical Characteristics
(1) TFT- LCD
(2) Backlight
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22" LCD Color Monitor AOC 212Va
5. Block Diagram
5.1 Software Flow Chat
1
2
N
4
5
Y
6
7
Y
Y
N
N
3
18
9
10
Y
N
N
12
Y
14
19
N
13
15
11
17
N
Y
N
Y
16
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
A_
5.2 Electrical Block Diagram
5.2.1 Main Board
Flash Memory
PM25LV010-25 SCE
(U402)
Panel Interface
(CN101)
Scalar TSUMU58WHJ-LF
(Include MCU, ADC, OSD)
(U401)
Key Control
Interface
(CN403)
EEPROM
24LC16B/SNG
(U403)
SDA
SCL
Crystal
14.318MHZ
(X401)
H sync
V sync
D-Sub
Connector
(CN405)
DDCA_SDA,
DDC
EEPROM
M24C02
(U404)
RGB
SCL
Digital Video
DVI
Connector
(CN406)
DDCD_SDA,
DDCD_SCL
EEPROM
M24C02
(U405)
Signal
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22" LCD Color Monitor AOC 212Va
5.2.2 Inverter/Power Board
AC input
EMI filter
Bridge
Rectifier
and Filter
Transformer
Rectifier
diodes
Start Circuit: R904, R932, R933
CN902
Lamp
Output
Circuit
Feedback
Circuit
PWM
Control IC
Over
Voltage
Transformer
Feedback
Circuit
MOSFET
PWM
Control IC
ON/OFF
Control
DIM
DIM
12V
5V
ON/OFF
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