AOC e2040Va User manual

20" LCD Color Monitor AOC e2040Va
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Service
Service
Service
HorizontalFrequency
30-83 kHz
TABLEOFCONTENTS
Description Page Description Page
Description Page
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
Table Of Contents.......…….................……...........…........1
Revision List.…........................………................……......2
1. Monitor Specification.................................………........3
2.LCD Monitor Description…………………………….......4
3. Operation Instruction…………...................…...........5
3.1 General Instructions.....................................…...........5
3.2 Control Button……………………………..……...........5
3.3 Adjusting the Picture...........................…............5
4. Input/Output Specification............……………............8
4.1 Input Signal Connector............…..……................8
4.2 Factory Preset Display Modes.........................9
5 Panel Specification.....…………………........................10
5.1 Display Characteristics………………………………10
5.2 Optical Characteristics………………………………..10
5.3 Parameter guide line for CCFL Inverter……………..10
6
Block
Diagram
1
1
Table Of Contents.......…….................……...........…........1
Revision List.…........................………................……......2
1. Monitor Specification.................................………........4
2. LCD Monitor Description…………………………….......6
3. Operation Instruction…………...................…...........9
3.1 General Instructions.....................................….........9
3.2 Control Button……………………………..…….........9
3.3 Adjusting the Picture...........................…...........9
4. Input/Output Specification............……………............13
4.1 Input Signal Connector............…..……................13
4.2 Factory Preset Display Modes...........................14
5 Panel Specification.....…………………........................15
5.1 Display Characteristics………………………………15
5.2 Optical Characteristics……………………………….16
5.3 Electrical Characteristics……………….…………..17
6. Block Diagram…….…................………….........18
6.1 Software Flow Chart…….…..........………….........18
6.2 Electrical Block Diagram………...………...…......20
7. Schematic……………………………………………. 22
7.1 Main Board…………..............................................22
7.2 Power Board....……………....................................27
7.3 Light Sensor Board…………………………………29
8. PCB Layout..…………............................................30
8.1 Main Board……………......................................30
8.2 Power Board….....................................................31
8.3 Key Board……………….....................................32
8.4 Light Sensor Board………………………………….32
9. Maintainability………...............................................33
9.1. Equipments and Tools Requirement.....................33
9.2. Trouble Shooting…………....................................34
10. Firmware and DDC Instruction……………….….41
11. White-Balance, Luminance adjustment.................42
12. Monitor Exploded View……..……………............44
13. BOM List....……....................................................45

20" LCD Color Monitor AOC e2040Va
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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 might 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 radiations 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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Revision List
Version Date Revision History Remark
A00 May.-20-2010 Initial release
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A01 Nov.-30-2010 Add new model TAAGNRNQWWA45NE
A02 Feb.-22-2011 Add new models
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20"LCDColorMonitor AOCe2040Va
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1. Monitor Specification

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20" LCD Color Monitor AOC e2040Va
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2. LCD Monitor Description
The LCD monitor will contain a main board, an adapter board, a converter board, a light sensor board, an audio
board and a key board which house the flat panel control logic, brightness control logic and DDC.
The power part will provide AC to DC Inverter voltage to drive the backlight of panel and the main board chips each
voltage.
AC-IN
100V-240V
Monitor Block Diagram
Converter board
Flat Panel and
LED backlight
Main Board RS232 Connector
For white balance
adjustment in factory
mode
LED Drive.
Video signal, DDC
HOST Computer
Key Board
Adapter
Light Sensor Board

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View and Dimension

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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 knobs are located at front panel of the
monitor.By changing these settings, the picture can be adjusted to your personal preferences.
3.2 Control Buttons
e-Sensor hot key.
When there is no OSD,Press ◄continuously to select the e-Sensor mode(e-Sensor mode hot key may not be
available in all models). e-Sensor:The infrared sensor can detect if user is in front of monitor and adjust monitor
brightness automatically to save power. When it is on, we can select the detect range [Near,Average,Far] by using
hot-key,.
Auto configure hot key
When there is no OSD, press Auto/Source button continuously about 2 second to do auto configure (Only for the
models with dual or more inputs).
Volume adjustment hot key
When there is no OSD,press Volume(►) to active volume djustment bar,press ◄or ►to adjust volume(Only for the
models with speakers)
3.3 Adjusting the Picture
OSD Setting
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 sub-menu . Once the desired function is highlighted, press MENU-button to activate it.
3) Press ◄or ►to change the settings of the selected function. Press ◄or ►to select another function in
sub-menu . Press AUTO to exit . If you want to adjust any other function, repeat steps 2-3.
4) 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.
5）e-Sensor hot key: When there is no OSD,Press ◄continuously to select the e-Sensor mode(e-Sensor mode hot
key may not be available in all models).
6) Volume adjustment hot key: When there is no OSD,press Volume(►) to active volume djustment bar,press ◄or
►to adjust volume(Only for the models with speakers)

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Notes:
1) If the product has only one signal input, the item of "Input Select" is disable to adjust.
2) If the product screen size is 4:3 or input signal resolution is wide format, the item of "Image Ratio" is disable to
adjust.
3) One of DCR, Color Boost, and Picture Boost functions is active, the other two function is turned off accordingly.
Luminance
Image Setup
Color Temperature

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Color Boost
Picture Boost
OSD Setup
Extra
Reset
Exit

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LED Indicator

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4. Input/Output Specification
4.1 Input Signal Connector
4.1.1 D-SUB connector
4.1.2 DVI connector

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4.2 Factory Preset Display Modes

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5 Panel Specification
5.1 Display Characteristics
LM200WD3-TLA1 is a Color Active Matrix Liquid Crystal Display with an integral Light Emitting Diode(LED)
backlight system. The matrix employs a-Si Thin Film Transistor as the active element. It is a transmissive type
display operating in the normally white mode. It has a 20.0 inch diagonally measured active display area with HD+
resolution (900 vertical by 1600 horizontal pixel array) Each pixel is divided into Red, Green and Blue sub-pixels or
dots which are arranged in vertical stripes.

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5.2 Optical Characteristics

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5.3 Electrical Characteristics
1.TFT LCD Module:
Ta = 25 ± 2 ºC
Note :
1. The specified current and power consumption are under the VLCD=5.0V, 25 ± 2°C,fV=60Hz condition whereas
mosaic pattern(8 x 6) is displayed and fV is the frame frequency.
2. The current is specified at the maximum current pattern.
3. Permissive power ripple should be measured under VCC=5.0V, 25°C, fV (frame frequency)=75Hz condition and
At that time, we recommend the bandwidth configuration of oscilloscope is to be under 20MHz.
4. The duration of rush current is about 5ms and rising time of power Input is 500us ± 20%.
2.Back Light Unit:
Ta = 25 ± 2 ºC

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6. Block Diagram
6.1 Software Flow Chart
1
2
N
Y
5
Y
N
10
Y
N
12
Y
N
7
Y
N
6
4
3
8
9
14
11
13
Y
N
15
Y
N
16
17
19
Y
N
18

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REMARK:
1) MCU initialize.
2) Is the EEprom blank?
3) Program the EEprom by default values.
4) Get the PWM value of brightness from EEprom.
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 EEprom.Turn on the LED and set it to green color. Scalar initialize.
10) In standby mode?
11) Update the lifetime of back light.
12) Check the analog port, are they’re 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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6.2 Electrical Block Diagram
6.2.1 Scalar Board
FLASH MEMORY
Pm25LD020C-SCE
(U402)
Scalar NT68668AFG
(Include :MCU,ADC,OSD etc)
(U401)
LCD Interface
(CN301)
D-Sub
Connector
(CN101)
H sync
V sync
RGB
EEPROM
AT24C02BN
(U101)
DDC1_SCL
DDC1_SDA
Crystal 12MHZ
(X401)
DVI
Connector
(CN102)
EEPROM
AT24C02BN
(U102)
DDC2_SCL
DDC2_SDA
Key Control
Interface
(CN401)
DVI
Input
signal