AOC LM927U User manual
AOC LM927U
1
SERVICE MANUAL
19” LCD Monitor
LM927U
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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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……………………………………………………………………………… 11
4.4 Panel Specification…………………………………………………………………………………….… 11
4.4.1 Panel Feature…………………………………………………………………………………………. 11
4.4.2 Display Characteristics……………………………………………………………………………….. 11
4.4.3 Optical Characteristics……………………………………………………………………………… 12
4.4.4 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………………………………………………………………………………………………….… 19
6.1 Main Board………………………………………………………………………………………………….. 19
6.2 Power Board…………………………………………………………………….………………………… 25
6.3 Audio Board…………………………………………………………………….………………………… 28
7. PCB Layout……………………………………………………………………………………………………. 29
7.1 Main Board………………………………………………………………………………………………….. 29
7.2 Power Board…………………………………………………………………….………………………… 30
7.3 Audio Board…………………………………………………………….………………………………… 31
7.4 Key Board………………………………………………………………………….……………………… 31
7.5 USB Board…………………………………………………………………………………………………. 31
7.6 CNPC Board…………………………………………………………………….………………………… 31
8. Maintainability…………………………………………………………………………………………………. 32
8.1 Equipments and Tools Requirement…………………………………………………………………… 32
8.2 Trouble Shooting……………………………………………………………………………………….… 33
8.2.1 Main Board…………………………………………………………………………………………... 33
8.2.2 Power /Inverter/Board……………………………………………………………………………….. 36
8.2.3 Keypad Board……………………………………………………………………………………….. 38
9. White-Balance,Luminance adjustment……………………………………………………………….… 39
10. EDID Content………………………………………………………………………………………………. 40
11. BOM LIST……………………………………………………………………………………………………... 41
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4
MONITOR SPECIFICATIONS
Driving system TFT Color LCD
Size 48.0cm(19.0")
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
Display Color 16.7M colors (RGB 8-bit data)
Dot Clock 135MHz
Contrast Ratio 700:1
White Luminance 250cd/m2
Max. Resolution 1280 x 1024
Plug & Play VESA DDC2BTM
ON Mode<50W
Power Consumption
OFF Mode<2W
Power Source 100~240VAC,47~63Hz
Maximum Screen Size Horizontal : 376.32mm
Vertical: 301.06mm
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 control buttons are located in the side 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.
-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.
LED = GREEN, BLINKING (0.5s period) —Out of Range
NO. Name Within OSD Without OSD
1 Auto 1. Exit Sub menu
2. Exit the menu item
Run the Auto Adjust when this
button keep to push for 2 second
2 VOL - / 1.Move the cursor to left
2.Adjust down when menu item selected
Hot key to decrease the volume
3 VOL+ / 1.Move the cursor to right
2.Adjust up when menu item selected
Hot key to increase the volume
4 MENU 1.Enter the OSD sub menu
2.Select the OSD menu
Open OSD menu
5 POWER Power On / Off Power On / Off
Auto/Exit
VOL- /
VOL+ /
MENU
POWER
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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
A
djust Picture Phase to reduce
Horizontal-Line noise
Image Setup
Clock
A
djust picture Clock to reduce
Vertical-Line noise.
H. Position
A
djust 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.
User / Green
Green Gain Digital-register.
Color Temp.
User / Blue
Blue Gain from Digital-register.
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Yes
N/A
A
uto 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
A
djust 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 PI N NO. DESCRIPTION
1. Red Video 9. No Pin!
2. Green Video 10. Logic Ground
3. Blue Video 11. Monitor Ground
4. Monitor Ground 12. DDC-Serial Data
5. DDC-Return 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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4.2 Factory Preset Display Modes：
VESA MODES
Horizontal Vertical
Mode Resolution Total
Nominal
Frequency
+/- 0.5kHz
Sync
Polarity
Nominal
Freq.
+/- 1 Hz
Sync
Polarity
Nominal
Pixel
Clock
(MHz)
640x480@60Hz 800 x 525 31.469 N 59.940 N 25.175
640x480@72Hz 832 x 520 37.861 N 72.809 N 31.500
VGA
640x480@75Hz 840 x 500 37.500 N 75.00 N 31.500
800x600@56Hz 1024 x 625 35.156 N/P 56.250 N/P 36.000
800x600@60Hz 1056 x 628 37.879 P 60.317 P 40.000
800x600@72Hz 1040 x 666 48.077 P 72.188 P 50.000
SVGA
800x600@75Hz 1056x625 46.875 P 75.000 P 49.500
1024x768@60Hz 1344x806 48.363 N 60.004 N 65.000
1024x768@70Hz 1328x806 56.476 N 70.069 N 75.000
XGA
1024x768@75Hz 1312x800 60.023 P 75.029 P 78.750
1280x1024@60Hz 1688x1066 63.981 P 60.020 P 108.000
SXGA
1280x1024@75Hz 1688x1066 79.976 P 75.025 P 135.000
IBM MODES
Horizontal Vertical
DOS 720x400@70Hz 900 x 449 31.469 N 70.087 P 28.322
DOS 640x400@70Hz 800 x 449 31.469 N 70.087 P 25.175
XGA 1024x768@72Hz 1304 x 798 57.515 P 72.1 P 75.000
MAC MODES
VGA
640x480@67Hz 864x525 35.000 N 66.667 N 30.240
SVGA
832x624@75Hz 1152x667 49.725 N 74.551 N 57.2832
1024x768@60Hz 1312x813 48.780 N 60.001 N 64.000XGA
1024x768@75Hz 1328x804 60.241 N 74.927 N 80.000
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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)
4.4 PANEL SPECIFICATION
4.4.1 Panel Feature
This specification applies to the 19.0 inch Color TFT-LCD Module M190EN02.
The display supports the SXGA (1280(H) x 1024(V)) screen format and 16.7M colors (RGB 8-bits data).
All input signals are 2 Channel LVDS interface compatible.
This module does not contain an inverter card for backlight.
4.4.2 Display Characteristics
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5. Block Diagram
5.1 Monitor Exploded View
HOLDER LIFT
BEZEL 34G1239
PANEL
KEY BOARD
15G5960
MAIN FRAME
SHIELD 85G651-3 34G1240
REAR COVER
HINGE ASSY
37G 478-1
W33G4673
COVER VESA
15G6050-1
HOLDER SPRING
BRACKET
33G4650
BASE 34G1245
STAND 34G1243
W33G4649 GM
34G1242
15G5962-1
34G1241
SPK BOX COVER -F
SPK BOX COVER -R
BASE PLATE
33G4647
BUTTON FUNC
33G4642
STAND LIFT
34G1244
COVER TILT
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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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6. Schematic
6.1 Main Board
715L1150-B
VCC2.5
VLCD
VCPU
VAA1
PA[0..9]
VAA3VAA2
VLCD
VAA4
B2
4.SCALER
RIN
GIN
SOG
BIN
GNDR
GNDG
GNDB
HSYNC
VSYNC
R+
R-
G-
G+
B+
B-
CLK+
CLK-
CSZ
SCL
SDA
HWRESET
INT
Volume
AdjBACKLITE
PA[0..9]
PB[0..9]
VCC2.5
VCC3.3
VAA1
VAA2
VAA3
VAA4
DDC_CLK
DDC_DAT
B1
3.INPUT
RIN
GIN
BIN
VSYNC
GNDR
GNDG
GNDB
ST_DET1 HSYNC
SOGDDC_CLK
DDC_DAT
ST_DET2
R+
R-
G-
G+
B+
B-
CLK+
CLK-
B5
5.PANEL INTERFACE
VLCD
PB[0..9]
PA[0..9]
MST8131A SCHEMATIC
VCC3.3
VAA1
TOP
A
MST8131A for AOC
B
16Friday, March 26, 2004
Title
Size Document Number Rev
Date: Sheet of
VCC5V
VCC12V
B4
2.POWER
onPanel_5V/3.3V
onBACKLITE
AdjBACKLITE
VCC3.3
VCC2.5
VAA1
VAA2
VAA3
VAA4
VCC5V
VCC12V
VLCD
VCPU
VAA2
VCPU PB[0..9]
B3
6.MCU
onBACKLITE
ST_DET2
onPANEL_5V/3.3V
SDA
INT
CSZ
DDC_DAT
ST_DET1
SCL
HWRESET
DDC_CLK
Volume
VCC5V
VCC12V
VCPU
VAA3
VCC12V VCC5V
VAA4VCC3.3
VCC2.5
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R211
10K 1/16W
VCC2.5 4
VCC12V
VLCD
Q203
AO3401
onBACKLITE 6
VCPU 6
VAA1
DIM
VCC5V 3,6
VCC5V
VAA3 4
R208
10K 1/16W
R206
10K 1/16W
GND
C216
0.1uF
R209
0 1/16W
VCC12V 6
D202
DIODE
C212
0.1uF
C
BE
VCPU
Brightness
VCC5V
VCC5V+
FB201
600 OHM
R210
NC
VAA1 4
VCC5V+
C203
0.1uF
SOT-223
R204
10K 1/16W
Q202
PMBS3904
32
1
R201 4.7K 1/16W
VCC12V
U202
AIC1084-33M
3
1
2
VIN
ADJ
VOUT
VAA2
R205 4.7K 1/16W
R207 4.7K 1/16W
VAA4
VCC3.3
VAA4 4
+
C202
220uF/25V
C205
0.1uF
VCC5V
ON_OFF
D201SCHOTTEYDIODE
VAA2 4
C201
0.1uF
VCC12V
VAA3
GND
AdjBACKLITE4
POWER
A
MST8131A for AOC
B
26Friday, March 26, 2004
Title
Size Document Number Rev
Date: Sheet of
VCC3.3 4
onPanel_5V/3.3V6
U201
RT9164-25CG
3 2
1
VI VO
GND
VCC5V
C207
0.1uF
GND
R212 4.7K 1/16W
+
C215
47uF/16V
GND
VLCD 5
R202
10K 1/16W
VCC2.5
GND
C
BE
+
C211
47uF/16V
+
C206
10uF/16V
VCC3.3
VCC5V+
C214
0.1uF
GND
C210
0.1uF
CN201
CON402(PITCH 2.54)
1
3
5
7
9
11
2
4
6
8
10
12
VCC5V
R203
1K 1/16W
VCC5V
VCC5V
+
C208
10uF/16V
+
C204
220uF/25V
Q201
PMBS3904
32
1
TO-263
Q204
PMBS3904
32
1
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