AOC LM925 User manual

AOC LM925
1
19” LCD MONITOR
LM925
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 RE LIABILITY FOR
CHANGES, ERRORS OR OMISSIONS.
SERVICE MANUAL
http://www.wjel.net

AOC LM925
2
Table of Content
Revision List…………………………………………………………………………………………………………. 4
1. Monitor Specifications………………………………………………………………………………………….. 4
2. LCD Monitor Description……………………………………………………………………………………….. 5
3. Operating Instructions………………………………………………………………………………………….. 6
3.1 General Instructions…………………………………………………………………………………………... 6
3.2 Front Panel Control……………………………………………………………………………….………….. 6
3.3 Adjusting the Picture………………………………………………………………………………………….. 7
4. Input/Output Specification……………………………………………………………………………………... 9
4.1 Input Signal Connector……………………………………………………………………………………….. 9
4.2 Power Supply Requirements………………………………………………………………………………… 9
4.3 Factory Preset Display Modes……………………………………………………………………………….. 10
4.4 Panel Specification………………………………………………………………………………………….… 11
4.4.1 Panel Features…………………………………………………………………………………………… 11
4.4.2 Display Characteristics………………………………………………………………………………….. 11
4.4.3 Optical Characteristics…………………………………………………………………………………… 12
4.4.4 Electrical Characteristics………………………………………………………………………………… 13
5. Block Diagram………………………………………………………………………………………………….… 14
5.1 Monitor Exploded View……………………………………………………………………………………….. 14
5.2 Software Flowing Chart……………………………………………………………………………….……… 15
5.3 Electrical Block Diagram……………………………………………………………………………………… 17
5.3.1 Main Board………………………………………………………………………………………………... 17
5.3.2 Inverter/Power Board………………………………………………………….…………………………. 18
6. Schematic……………………………………………………………………………………………………….… 19
6.1 Main Board…………………………………………………………………………………………………….. 19
6.2 Audio Board……………………………………………………………………….………………………….. 25
6.3 Power Board……………………………………………………………………….………………………….. 26
7. PCB Layout………………………………………………………………………………………………………. 29
7.1 Main Board…………………………………………………………………………………………………….. 29
7.2 Audio Board…………………………………………………………….……………………………………… 30
7.3 Power Board………………………………………………………………………….……………………….. 31
7.4 Key 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……………………………………………………………………………………………………. 41
11. BOM LIST………………………………………………………………………………………………………... 42
http://www.wjel.net

AOC LM925
3
Revision List
Version Date Revision History TPV Model Name
A00 Feb-08-06 Initial Release T980KH4HBAA1AP
A01 Oct-14-2006 Add TPV Model in item11 T980KA2HLAMGAP
http://www.wjel.net

AOC LM925
4
1. Monitor Specifications
Items Description
Driving system TFT Color LCD
Type HSD190ME13
Size 48.0cm(19.0")
Pixel pitch 0.294mm (H) x 0.294mm (V)
Viewable angle 150(H) 135(V)
LCD Panel
Response time 8 ms
Sync. Type H/V TTL
Input Signal 15Pin Analog
H-Frequency 30kHz – 83kHz
Input
V-Frequency 50-75Hz
ON Mode ≤37W
Power Consumption
OFF Mode ≤2W
Display Color 16.1M (6-bits+FRC)
Contrast Ratio 600:1
Dot Clock 135MHz
White Luminance 250cd/m2
Max. Resolution 1280 x1024
Plug & Play VESA DDC2BTM
Power Source 100~240VAC,47~63Hz
Maximum Screen Size Horizontal : 376.32mm
Vertical: 301.056mm
Environmental
Conditions
Operating Temp: 0°C to 40°C
Storage Temp: -20°C to 60°C
Operating Humidity: 15% to 90%
http://www.wjel.net

AOC LM925
5
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.
Video signal, DDC
CCFT Drive.
PWPC Board
(
Include Ada
p
ter and Inverter
)
Flat Panel and
CCFL backlight
Main Board
RS232 Connector
For white balance
adjustment in factory
mode
HOST Computer
AC-IN
100V-240V
Monitor Block Diagram
Audio board Keyboard
http://www.wjel.net

AOC LM925
6
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 position. The power indicator will light up.
3.2 Front Panel Control
-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.
NO. Name Within OSD Without OSD
1 Auto Exit OSD or back to previous menu Auto configuration
2 VOL-/ 1.Move the cursor to left
2.Decrease the value of the selected item Activate the audio menu
3 POWER Power On / Off Power On / Off
4 VOL+ / 1.Move the cursor to right
2.Increase the value of the selected item Activate the audio menu
5 MENU Select Function or select Sub menu Activate OSD main menu
http://www.wjel.net

AOC LM925
7
3.3 Adjusting The Picture
The Description For Control Function:
Main Menu
Item
Main
Menu
Icon
Sub Menu
Item
Sub Menu
Icon Description Adjust Range Reset Value
Contrast
Contrast from Digital-register. 0-100 Recall Cool
Contrast Value
Luminance
Brightness
Backlight Adjustment 0-100
Recall Cool
Brightness
Value
Focus
Adjust Picture Phase to reduce
Horizontal-Line noise 0-100 Do Auto Config
Image Setup
Clock
Adjust picture Clock to reduce
Vertical-Line noise. 0-100 Do Auto Config
H. Position
Adjust the horizontal position of
the picture. 0-100 Do Auto Config
Image
Position V. Position
Adjust the vertical position of the
picture. 0-100 Do Auto Config
Warm N/A
Recall warm Color Temperature
from EEPROM. N/A
Cool N/A
Recall cool Color Temperature
from EEPROM. N/A
sRGB N/A
Recall sRGB Color Temperature
from EEPROM. N/A
User / Red
Red Gain from Digital-register. 0-100
User /
Green
Green Gain from Digital-register. 0-100
Color Temp.
User / Blue
Blue Gain from Digital-register. 0-100
The Color
Temperature
will be set to
Cool.
The User
R/G/B value
(default is 100)
will not be
Modified by
Reset function.
Auto Config
(Analog-Only
Yes N/A
Auto Adjust the H/V Position,
Focus and Clock of picture. N/A N/A
http://www.wjel.net

AOC LM925
8
Model) No N/A Do not execute Auto Config,
return to main menu. N/A N/A
H. Position
Adjust the horizontal position of
the OSD. 0-100 50
V. Position
Adjust the vertical position of the
OSD. 0-100 50
OSD Setup
OSD
Timeout
Adjust the OSD timeout. 10-120 10
English N/A Set OSD display language to
English. N/A
Deutsch N/A Set OSD display language to
German. N/A
Français N/A Set OSD display language to
French. N/A
Español N/A Set OSD display language to
Spain. N/A
Portuguese N/A Set OSD display language to
Italian. N/A
Language
简体中文 N/A Set OSD display language to
simplified Chinese. N/A
The Language
will be set to
English.
Information
Information N/A
Show the resolution, H/V
frequency and input port of
current input timing.
N/A N/A
Yes N/A
Clear each old status of
Auto-configuration and set the
color temperature to Cool.
N/A N/A
Reset
No N/A
Do not execute reset, return to
main menu. N/A N/A
Exit
N/A N/A Exit OSD N/A N/A
http://www.wjel.net

AOC LM925
9
4. Input/Output Specification
4.1 Input Signal Connector
Pin No. Description Pin No. Description
1. Red 9. No Pin!
2. Green 10. Logic Ground
3. Blue 11. Monitor Ground
4. Monitor Ground 12. DDC-Serial Data
5. DDC-Return 13. H-Sync
6. R-Ground 14. V-Sync
7. G-Ground 15. DDC-Serial Clock
8. B-Ground
VGA connector layout
15
610
11 15
4.2 Power Supply Requirement
A/C Line voltage range : 100 V ~ 240 V
A/C Line frequency range : 50 ±3Hz, 60 ±3Hz
Input 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
Voltage : 5VDC ± 5％; 12VDC± 5％
CURRENT : 1.5Amp (5V) ；2 Amp (12V)
http://www.wjel.net

AOC LM925
10
4.3 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 64.000
XGA
1024x768@75Hz 1328x804 60.241 N 74.927 N 80.000
http://www.wjel.net