AOC LM923 User manual

AOC LM923
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SERVICE MANUAL
19” LCD MONITOR
LM923
THESE DOCUMENTS ARE FOR REPAIR SERVICE INFORMATION ONLY. EVERY REASONABLE EFFORT HAS
BEEN MADE TO ENSURE THE ACCURACY OF THIS MANUAL; WE CANNOT GUARANTEE THE ACCURACY OF
THIS INFORMATION AFTER THE DATE OF PUBLICATION AND DISCLAIMS RELIABILITY FOR CHANGES,
ERRORS OR OMISSIONS.
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AOC LM923
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Table of Content
Revision List…………………………………………………………………………………………………………. 3
1. Monitor Specifications………………………………………………………………………………………….. 4
2. LCD Monitor Description……………………………………………………………………………………….. 5
3. Operating Instructions………………………………………………………………………………………….. 6
3.1 General Instructions…………………………………………………………………………………………... 6
3.2 Control Buttons………………………………………………………………………………………………... 6
3.3 Adjusting the Picture………………………………………………………………………………………….. 7
4. Input/Output Specification……………………………………………………………………………………... 9
4.1 Input Signal Connector……………………………………………………………………………………….. 9
4.2 Factory Preset Display Modes……………………………………………………………………………….. 10
4.3 Power Supply Requirements………………………………………………………………………………… 10
4.4 Panel Specification………………………………………………………………………………………….… 11
4.4.1Display Characteristics………………………………………………………………………………… 11
4.4.2Optical Characteristics…………………………………………………………………………………… 11
4.4.3 Parameter Guide Line For CCFL Inverter……………………………………………………………… 12
5. Block Diagram………………………………………………………………………………………………….… 13
5.1 Monitor Exploded View……………………………………………………………………………………….. 13
5.2 Software Flow Chart…………………………………………………………………………………………... 14
5.3 Electrical Block Diagram……………………………………………………………………………………… 16
5.3.1 Main Board………………………………………………………………………………………………... 16
5.3.2 Inverter/Power Board………………………………………………………….…………………………. 17
6. Schematic……………………………………………………………………………………………………….… 18
6.1 Main Board…………………………………………………………………………………………………….. 18
6.2 Audio Board……………………………………………………………………….………………………….. 24
6.3 Power Board……………………………………………………………………….………………………….. 25
7. PCB Layout………………………………………………………………………………………………………. 28
7.1 Main Board…………………………………………………………………………………………………….. 28
7.2 Audio Board…………………………………………………………….……………………………………… 29
7.3 Power Board………………………………………………………………………….……………………….. 30
7.4 Key Board……………………………………………………………………………………………………… 30
8. Maintainability……………………………………………………………………………………………………. 31
8.1 Equipments and Tools Requirement………………………………………………………………………… 31
8.2 Trouble Shooting…………………………………………………………………………………………….… 32
8.2.1 Main Board………………………………………………………………………………………………... 32
8.2.2 Power /Inverter/Board……………………………………………………………………………………. 35
8.2.3 Keypad Board…………………………………………………………………………………………….. 37
9. White-Balance, Luminance adjustment………………………………………………………………….… 38
10. EDID Content……………………………………………………………………………………………………. 39
11. BOM List………………………………………………………………………………………………………... 40
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REVISION LIST
Revision Date Revision History TPV Model
A00 Nov-28-05 First Version Release T980KAXHLFMRA
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1.MONITOR SPECIFICATIONS
ITEMS SPECIFICATIONS
Driving system TFT LCD
Size 48.0cm(19.0")
Type M190EN02
Pixel pitch 0.294mm( H )x 0.294mm( V )
Viewable angle 170˚(H) 170˚(V)
LCD Panel
Response time (type) 25 ms for AU panel
Sync. Type H/V TTL
H-Frequency 30kHz – 83kHz
Input
V-Frequency 55-75Hz
Dot Clock 135MHz
Contrast Ratio 700:1
White Luminance 250cd/m2
Max. Resolution 1280 x 1024
Plug & Play VESA DDC2BTM
ON Mode<55W
Power Consumption
OFF Mode<2W
Power Source 100~240VAC,47~63Hz
Display Color 16.7M colors (RGB 8-bits data)
Maximum Screen Size Horizontal : 376.32mm
Vertical: 301.056mm
Environmental
Considerations
Operating Temp: 0°C to 40°C
Storage Temp: -20°C to 60°C
Operating Humidity: 15% to 90%
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2. LCD MONITOR DESCRIPTION
The LCD MONITOR will contain a main board, a power board, a keypad board and an 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.
HOST Computer
AC-IN
100V-240V
PWPC board
(
Include: ada
p
ter
,
inverter
)
Flat Panel and
CCFL backlight
Main Board
RS232 Connector
For white balance
adjustment in factory
mode
CCFL Drive.
Video signal,
Monitor Block Diagram
Keyboard
Audio 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 buttons are located at front panel of the
monitor. By changing these settings, the picture can be adjusted to your personal preferences.
-The power cord should be connected.
-Connect the video cable from the monitor to the video card.
-Press the power button to turn on the monitor, the power indicator will light up.
3.2 CONTROL BUTTONS
-Power Button:
When pressed, the monitor enters the off mode, and the LED turns blank. Press again to restore normal status.
-Left / Right Button:
The Left/Right Button is used to control the monitor functions. Press to switch functions or adjust settings.
- Auto Adjust Key:
The Auto Adjust Key is used to automatically set the H Position, V Position, Clock and Phase.
-Power Indicator:
Green — Power On mode.
Orange — Power Saving mode.
Blank —Power Off Mode.
O. Name Within OSD Without OSD
1 Auto/Exit Exit OSD or back to previous menu Auto configuration
2 Volume down/
1.Move the cursor to down
2.Decrease the value of the selected item Activate the volume menu
3 Volume up / 1.Move the cursor to up
2.Increase the value of the selected item
Activate the volume menu
4 MENU/ENTER Select Function or select Sub menu Activate OSD main menu
5 POWER Power On / Off Power On / Off
6 LED Green—On Orange—Save Green—On Orange—Save
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3.3 ADJUSTING THE PICTURE
Adjustment steps:
1. Press the MENU-button to activate the OSD window.
2. Press < or > to select the desired function.
3. Press the MENU-button to select the function that you want to adjust.
4. Press < or > to change the settings of the current function.
5. To exit and save, select the exit function, or leave the monitor alone for 10 seconds. If you want to adjust any
other function, repeat steps 2-4.
OSD TABLE:
Main Menu
Item
Main Menu
Icon Sub Menu Item Sub Menu Icon Description
Contrast Contrast from Digital-register.
Luminance
Brightness
Backlight Adjustment
Focus
Adjust Picture Phase to reduce
Horizontal-Line noise
Image Setup
Clock
Adjust picture Clock to reduce
Vertical-Line noise.
H. Position
Adjust the horizontal position of
the picture.
Image
Position V. Position
Adjust the vertical position of the
picture.
Warm N/A
Recall Warm Color Temperature
from EEPROM.
Cool N/A
Recall Cool Color Temperature
from EEPROM.
User / Red
Red Gain from Digital-register.
Color Temp.
User / Green
Green Gain Digital-register.
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AOC LM923
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User / Blue
Blue Gain from Digital-register.
Yes
N/A Auto Adjust the H/V Position, Focus and Clock of picture.
Auto Config
(Analog-Only
Model) No N/A
Do not execute Auto Config,
return to main menu.
H. Position
Adjust the horizontal position of
the OSD.
OSD Setup
V. Position
Adjust the vertical position of the
OSD.
OSD Timeout
Adjust the OSD timeout.
English N/A
Set OSD display language to
English.
Deutsch N/A
Set OSD display language to
German.
Français N/A
Set OSD display language to
French.
Español N/A
Set OSD display language to
Spain.
Italiano N/A
Set OSD display language to
Italian.
Language
简体中文 N/A Set OSD display language to
Simplified Chinese.
Information
Information N/A
Show the resolution, H/V
frequency and input port of current
input timing.
Yes N/A
Clear each old status of
Auto-configuration and set the
color temperature to Cool.
Reset
No N/A
Do not execute reset, return to
main menu.
Exit
N/A N/A Exit OSD
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4. INPUT/OUTPUT SPECIFICATION
4.1 INPUT SIGNAL CONNECTOR
PIN NO. DESCRIPTION PIN NO. DESCRIPTION
1. Red Video 9. +5V
2. Green Video 10. Detect Cable
3. Blue Video 11. NC
4. Ground 12. DDC-Serial Data
5. Ground 13. H-Sync
6. Red Ground 14. V-Sync
7. Green Ground 15. DDC-Serial Clock
8. Blue Ground
VGA connector layout
15
610
11 15
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AOC LM923
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4.2 FACTORY PRESET DISPLAY MODES：
STANDARD RESOLUTION HORIZONTAL
FREQUENCY
VERTICAL
FREQUENCY
Dos-mode 720 x 400 31.47kHz 70.0Hz
640 × 480 31.47kHz 60.0Hz
VGA
640 × 480 37.50kHz 75.0Hz
800 × 600 37.879kHz 60.0Hz
SVGA
800 × 600 46.875kHz 75.0Hz
1024 × 768 48.363kHz 60.0Hz
1024 × 768 56.476kHz 70.0Hz
XGA
1024 × 768 60.021kHz 75.0Hz
1280 × 1024 64.000kHz 60.0Hz
SXGA
1280 × 1024 80.000kHz 75.0Hz
4.3 POWER SUPPLY REQUIREMENTS
A/C Line voltage range 100 V ~ 240 V
A/C Line frequency range 50 ±3Hz, 60 ±3Hz
Current 1.5A max at 100V; 0.8A max at 240 V
Peak surge current < 55A peak at 240 VAC and cold starting
Leakage current < 3.5mA
Power line surge No advance effects (no loss of information or defect)
with a maximum of 1 half-wave missing per second
DC output Voltage 5VDC ± 5％; 12VDC± 5％
CURRENT 1.5Amp (5V) ；2 Amp (12V)
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