AOC e940Swa User manual

18.5" LCD Color Monitor AOC e940Swa
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Service
Service
Service
HorizontalFrequency
30-80 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…………...................…...........6
3.1 General Instructions.....................................…...........7
3.2 Control Button……………………………..……...........7
3.3 Adjusting the Picture...........................…............7
4. Input/Output Specification............……………............11
4.1 Input Signal Connector............…..……................11
4.2 Factory Preset Display Modes...........................12
5 Panel Specification.....…………………........................13
5.1 Display Characteristics………………………………13
5.2 Optical Characteristics……………………………….14
5.3 Electrical Characteristics……………….…………..15
6. Block Diagram…….…................………….........17
6.1 Software Flow Chart…….…..........………….........17
6.2 Electrical Block Diagram………...………...…......19
7. Schematic……………………………………………. 22
7.1 Main Board…………..............................................22
7.2 Power Board....……………....................................26
8. PCB Layout..…………............................................31
8.1 Main Board……………......................................30
8.2 Power Board….....................................................32
8.3 Key Board……………….....................................36
9. Maintainability………...............................................37
9.1. Equipments and Tools Requirement.....................37
9.2. Trouble Shooting…………....................................38
10.Firmware and DDC Instruction………………….….44
11. White-Balance, Luminance adjustment.................45
12. Monitor Exploded View……..……………............47
13. BOM List....……....................................................48

18.5" LCD Color Monitor AOC e940Swa
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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.)

18.5" LCD Color Monitor AOC e940Swa
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Revision List
Version Date Revision History Remark
A00 May.-20-2010 Initial release T89ANRNQWWA26NE
A01 Aug.-25-2010 Add new Models
T89ANRNQWWA16NE
T8AANT2QWWA56NE
T8AANT2QWWA66NE
A02 Sep.-25-2010 Add new Models
T89ANT2CWWA38NE
T8AANT2CWWA38NE
T8AANT2QWWA36NE
T8AANT2QWWA46NE
A03 Oct.-15-2010 Add new Models
T8AANRNQWWA86NE
T8AANT2CWWA48NE
T8AANT2QWWK66NE
T8AANT2QWWK86NE
A04 Nov.-23-2011
Add Converter board PCB
（715G4128P03000004C）
T8AANT2QWWR56NE
T8AANT2QWWR46NE
T8AANT2QWWR36NE
T8AANT2QWWR66NE
Add Converter board PCB
（715G4119P02001004C）
T8AANT2QWWA76NE
T8AANT2QWWA86NE
T8AGNT2QWWA16NE
T8AGNT2QWWA26NE
T8BANT2QWWA16NE
T8BANT2QWWA26NE
T8BGNT2CWWA18NE

18.5"LCDColorMonitor AOCe940Swa
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1. Monitor Specification

18.5"LCDColorMonitor AOCe940Swa
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18.5" LCD Color Monitor AOC e940Swa
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2. LCD Monitor Description
The LCD monitor will contain a main board, an adapter board, a converter 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.
Monitor Block Diagram
AC-IN
100V-240V
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 Board

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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
4:3 or wide image ratio hot key：
When there is no OSD, press ►continuously to change 4:3 or wide image ratio. (If the product screen size is 4:3 or
input signal resolution is wide format, the hot key is disable to adjust)
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.
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.

18.5" LCD Color Monitor AOC e940Swa
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Luminance
Image Setup

18.5" LCD Color Monitor AOC e940Swa
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Color Temperature
Color Boost
Picture Boost
OSD Setup

18.5" LCD Color Monitor AOC e940Swa
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Extra
Reset
Exit
LED Indicator

18.5" LCD Color Monitor AOC e940Swa
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4. Input/Output Specification
4.1 Input Signal Connector
D-SUB connector

18.5" LCD Color Monitor AOC e940Swa
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4.2 Factory Preset Display Modes

18.5" LCD Color Monitor AOC e940Swa
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5 Panel Specification
5.1 Display Characteristics

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5.2 Optical Characteristics

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5.3 Electrical Characteristics
1.TFT LCD Module:

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2.Back Light Unit:

18.5" LCD Color Monitor AOC e940Swa
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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)
Key Control
Interface
(CN401)

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6.2.2 Inverter / Power Board
Adapter
715G3980P02000003S
Converter
715G3823P04000004S
715G4128P03000004C
EMI filter
Start Resistor
(R934, R906)
PWM Contro
LD7750GSl
(IC901)
Transformer
AC input 12V/3A
Bridge
Rectifier
and Filter
Rectifier
diodes
Power Switch
(Q901)
Photo coupler
(IC902) Regulator
(IC903)
ZD801
12V
MOSFET
(Q801)
DIM
ENA
L801
LED
(CN802)
LED
(CN803)
PWM Control
TA9690GN
(IC801,IC802)
D801
14.5V
MOSFET
(Q806)
DIM
ENA
L801
LED
(CN801)
LED
(CN804)
PWM Control
MP3389EF
(U801)