AOC n941S/plus User manual

ServiceManual AOCn941Splus
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LCD 显示器维修手册
English version
Brand：AOC
Model：n941S/plus
编制editor TPV-BJ-朱雨生 2011-11-24
审核 review TPV-BJ-常焕华 2011-11-24

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REVISION LIST
Version Release Date Revision History Model TPV Model No
A00 Nov-24-2011 Initial Release AOCn941S/plus T99ANSNYWVA1NNJ T9BENSNYWVA1NNJ
T9BANSNDWVA1NNE

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CONTENTS
1. LCD Specifications ................................................................................................................................ 4
1.1 Product Features....................................................................................................4
1.2 Factory preset modes ............................................................................................5
1.3 Introduction of new feature.....................................................................................5
1.4 VGA 15pin Connector ............................................................................................6
2. Operation instruction............................................................................................................................. 7
2.1 Connection.............................................................................................................7
2.2 Control Buttons ......................................................................................................7
2.3 OSD User mode adjustment ..................................................................................8
3. Panel Feature....................................................................................................................................... 10
3.1 General Specifications .........................................................................................10
3.2 Electrical Absolute Ratings...................................................................................10
3.3 Electrical Characteristics......................................................................................10
3.4 TFT LCD Module Block Diagram..........................................................................11
3.5 LCD module input terminal pin assignment..........................................................12
3.6 Optical Specifications...........................................................................................12
4. Disassembly SOP................................................................................................................................ 13
4.1 appropriate tools ..................................................................................................13
4.2 Disassembly SOP................................................................................................14
5.Block Diagram....................................................................................................................................... 18
5.1 LCD Block Diagram..............................................................................................18
5.2 MainBoard Block Diagram ...................................................................................18
5.3 Power Board Block Diagram................................................................................19
5.4 Software Flow Chart.............................................................................................20
6. Circuit Schematic................................................................................................................................. 21
6.1 Main Board 1-715G3225-1...................................................................................21
6.2 Power Board 715G2892-7 ...................................................................................26
6.3 Inverter part----.....................................................................................................27
6.4 Key Board 715G4007-K01...................................................................................28
7.Explore Views........................................................................................................................................ 29
8. PCB Layout........................................................................................................................................... 30
8.1 MainBoard -- 715G3225-1 ...................................................................................30
8.2 PowerBoard 715G2892-7 ....................................................................................32
8.3 KeyBoard ---715G4007........................................................................................33
9. Maintenance Trouble treatment......................................................................................................... 34
9.1 Maintainability Requirement.................................................................................34
9.2 Trouble Shooting..................................................................................................34
9.3 Software programming step.................................................................................38
9.4 Writing DDC program step...................................................................................43
9.5 Factory mode adjustment.....................................................................................45
10.BOM List .............................................................................................................................................. 47
10.1 Model：T99ANSNYWVA1NNJ ..........................................................................47

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1. LCD Specifications
1.1 Product Features
Monitor Model AOC n941S/plus
LCD Panel
Driving system TFT Color LCD
Active Display Area 481mm（19inch）diagpnal
408.24mm (W)×255.15mm(H)
Pixel Pitch 0.2835 mm×0.2835mm
Display Colors 16.7M Colors
Max. Resolution 1440 x 900@75Hz
Input
Video R,G,B Analog Interface，75ohm,0.7V
Separate Sync. H/V TTL
H-Frequency 30kHz—80kHz
V-Frequency 55Hz--75Hz
Dot Clock 136.75MHz
Plug & Play VESA DDC2B /CI
Connector D-Sub 15pin
USB HUB No
OSD 14 language OSD menu
Power Consumption ON Mode <25W
Power Saving Mode <0.5W
Switch OFF <0.5W
Power Source 90~264VAC,47~63Hz, 1.5A Max supply current
Dimensions(including stand) 456.75mm×375.5mm×149.85mm
Weight (N. W.): 3.5kg
Environmental
Considerations
Operating Temp: 0° to 40°C
Storage Temp.: -25° to 55°C
Operating Humidity : 10% to 85%
Altitude:
Operating ：0~ 3658m (0~ 12000 ft )
Non-Operating：0~ 12192m (0~ 40000 ft )
Safety FCC B CCC IEC950CB etc.

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1.2 Factory preset modes
STANDARD RESOLUTION HORIZONTAL
FREQUENCY VERTICAL FREQUENCY
VGA
640×480 31.469kHz 59.94Hz
640×480 35.00kHz 66.66Hz
640×350 37.861kHz 72.80Hz
640 × 480 37.50kHz 75.00Hz
DOS-mode 640 × 480 31.469kHz 70.087Hz
720 × 400 31.469kHz 70.087Hz
Mac-mode 832 ×624 49.725kHz 74.50Hz
SVGA
800 × 600 35.16kHz 56.25Hz
800 × 600 37.879kHz 60.317Hz
800 × 600 48.07kHz 72.188Hz
800 × 600 46.875kHz 75Hz
XGA
1024 × 768 48.363kHz 60Hz
1024 × 768 56.476kHz 70.069Hz
1024 × 768 57.50kHz 72.074Hz
1024 × 768 60.023kHz 75.029Hz
1024 × 768 60.241kHz 74.927Hz
WXGA 1440 × 900 55.93kHz 60Hz
1440 × 900 70.635kHz 75Hz
1.3 Introduction of new feature
This product is no USB interface. Only VGA Interface.
White Luminance 200cd/m2(typ)

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1.4 VGA 15pin Connector
Pin No. Description Pin No. Description
1. Red Input 9. +5VDC
2. Green Input 10. Logic GND
3. Blue Input 11. N/A
4. N/A 12. SDA- DDC-Serial Data
5. Connection detect 13. H Sync
6. Red GND 14. V Sync
7. Green GND 15. SCL- DDC-Serial Clock
8. Blue GND
VGA Connector layout 15
610
11 15

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2. Operation instruction
2.1 Connection
Connect the video cable from the video card of PC to the monitor.
The power cord should be connected.
Press the power button to turn on the monitor, the power indicator will light up.
2.2 Control Buttons
Control Description
1 Power Button To turn ON/OFF the moniteor, and power indicator (Green/Blue
and Amber/Orange).
2 Menu / Enter
Active main menu while no OSD display,enter next level on main
menu or sub menu status, or enter last level on adjustment bar..
Hotkey ,exit
34:3 or wide/ +
Hotkey,Audio volume adjust for VA,or chang 4:3 or wide image ratio
for SA .
OSD, increase current value of bar, or move to next item of menu
4 ECO mode(DCR)/ - If there is no OSD,select the ECO mode of brightness and DCR.
OSD, it will decrease current value of bar, or it will move to last
item of menu.
5 Auto / Exit
If there is no any OSD, select video source(DVI/RGB).
Press hold to 2s , it is auto configuration.
Exit current OSD and return to last level.

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2.3 OSD User mode adjustment
Hot key
┼─
AUTO Menu+Power
OSD Lock Function
Press “menu” and hold,with turn on “Power”, the OSD menu is locked. Again, the OSD menu is non-locked.
For the OSD menu function ,Please refer to “user manual” .
OSD Menu adjustment steps:
1.Press MENU button to display OSD main menu of as below, Press Left button or Right button may select other
main Menu.
2. Press MENU button to adjust items of each main menu.
3. Press Left button or Right button may select item you wish to enter.
4. Press MENU button to enter, and press Left button or Right button to adjust item you select.
5. Press EXIT button may back previous menu.
6. Repeat steps 2-5 to adjust an additional item, or select the EXIT button to return to previous menu.

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3. Panel Feature
This specification applies to the 19 inch-wide Color TFT-LCD Module M190PW01.
The display supports the WXGA+ (1440(H) x 900(V)) screen format and 16.7M colors(RGB
6-bits+HiFRC). All input signals are 2-Channel LVDS interface compatible. This module does
not contain an inverter board for backlight.
3.1 General Specifications
3.2 Electrical Absolute Ratings
Item Symbol Min Typ Max Unit
Power Supply Voltage Vcc -0.3 5 +6 V
Lamp voltage Vblh 666 700 814 Vrms
Lamp Current IL 3.0 6.5 8.0 mArms
Lamp Frequency FL 40 50 80 kHz
3.3 Electrical Characteristics
a) TFT LCD module

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b
) for backlight lamp (2CCFL)
3.4 TFT LCD Module Block Diagram

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3.5 LCD module input terminal pin assignment
3.6 Optical Specifications

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4. Disassembly SOP
4.1 appropriate tools
Phillips screwdriver
spacer screwdriver
C/D Disassembly
Tool
Gloves or soft cloth
Prepare soft cloth
and sponge as
working platform

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4.2 Disassembly SOP
Remove
screw×1

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Remove
bezel
Bezel for
n941s/plus
Remove buttons
Remove
screw×4
connector×3

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5.Block Diagram
5.1 LCD Block Diagram
5.2 MainBoard Block Diagram
n941S---715G3225
DC-AC inverter
AC-DC(5V/12V)
Power Board
Main Board
Key board
PC- VGA
/DDC
2CCFL backlight
Panel
LVDS
AC supply
90V-264V
Monitor Block Diagram
Input signal
Crystal 12MHz
(X401) Panel Interface
(CN403/405)
Scalar NT68168FG
(Include ADC, OSD, MCU)
(U401)
D-Sub Connector
(CN101)
EEPROM
PM25LD020C
(U402)
H sync
V sync
Key Board
Control
(CN401/402)
Voltage converter
5V
5V 3.3V 1.8V

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5.3 Power Board Block Diagram
-G2892-1-V0C
Fuse EMI Rectifier
BD901 Smoothing
Capacitor
C905
Transformer
T901
MOS
Q901
IC-PWM
IC901
16V
Rectifie
r
5V
Rectifie
r
16V
5V
Sense
resistor
Vcc
Rectifie
r
regulating
Sampling
PhotoCoupler
Vcc
Open Lamp Protection
16V DC
DIM control
DC-AC
Transformer
T801
High Voltage
Output
Resonance NET
Switching MOS
AO4620*2
AC input
100-240V
2- CCFL
PWM Control IC
IC801-TA9687
Current Sampling
Power part
Inverter part

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5.4 Software Flow Chart
Start
Initial_MCU
Check if DataBuffer Is blank
Check if Sum is chan
g
ed ? To Write default values
Read parameter_from Buffer
PowerHandler
Init_GlobalVariables
Initial_MCU Device
while
InputTiming
ModeHandler
MenuHandler
DebugHandler
if standby mode?
Brightness
Contrast
Language
InputType InputTimingStableCounter
OsdCounter
PowerDownCounter
LED turn-on
Show power on logo
if factory mode?
No signal message
UnsupportModeFlag
END
OSD Menu
Software Flow Chart
InputTiming
Phaes/Frequency
Image setup
Color
Oi
Enter factory mode OSD
Y
N
Y