AOC LM-729 Service Manual

LM-729 Service Manual Rev: A

SERVICE MANUAL

17” LCD Monitor

LM-729

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.

Page 1 of 61

LM-729 Service Manual Rev: A

Prepared: Shiwei

Date: Jul-30-03

Page 2 of 61

LM-729 Service Manual Rev: A

Revision History

Revision Date Page Items Modification

A Date:Jul-30-03 All First version release;

Page 3 of 61

LM-729 Service Manual Rev: A

Table of Contents

Table of Contents ---------------------------------------------------------------------------------------------------3

1. MONITOR SPECIFICATIONS ---------------------------------------------------------------------------5

2. LCD MONITOR DESCRIPTION ---------------------------------------------------------------------------6

3. OPERATING INSTRUCTIONS ---------------------------------------------------------------------------7

3.1 GENERAL INSTRUCTIONS -------------------------------------------------------------------------7

3.2 CONTROL BUTTONS ------------------------------------------------------------------------------------7

3.3 ADJUSTING THE PICTURE--------------------------------------------------------------------------------7

4. Input/Output Specification - -------------------------------------------------------------------------------10

4.1 Input Signal Connector --------------------------------------------------------------------------------10

4.2 Factory Preset Display Modes -------------------------------------------------------------------------- 11

4.3 Power Supply Requirements ------------------------------------------------------------------------ 12

4.3.1 Input Requirements -------------------------------------------------------------------------------------12

4.3.2 Output Requirements ------------------------------ ------------------------------------------------12

4.4 PANEL SPECIFICATION -------------------------------------------------------------------------------14

4.4.1 Panel Feature ------------------------------------------------------------------------------------------14

4.4.2 Display Characteristics --------------------------------------------------------------------------------14

4.4.3 Optical Characteristics -------------------------------------------------------------------------------14

4.4.4 Parameter guide line for CCFL Inverter ------------------------------------------------------14

5. Block Diagram ------------------------------------------------------------- -----------------------------15

5.1 Monitor Exploded View ------------------------------------------------------------------------------------15

5.2 Software Flow Chart -------------------------------------------------------------------------------------16

5.3 Electrical Block Diagram ------------------------------------------------------------------------------18

5.3.1 Main Board -------------------------------------------------------------------------------------------------18

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LM-729 Service Manual Rev: A

5.3.2 Inverter/Power Board -------------------------------------------------------------------------------------19

6. Schematic -------------------------------------------------------------------------------------------------------21

6.1 Main Board -----------------------------------------------------------------------------------------------21

6.2 AUDIO Board -----------------------------------------------------------------------------------------25

6.3 Key Board ------------------------------------------------------- ---------------------------------------26

6.4 Inverter/Power Board -----------------------------------------------------------------------------------27

7. PCB Layout -------------------------------------------------------------------------------------------------29

7.1 Main Board -----------------------------------------------------------------------------------------------29

7.2 Inverter/Power Board -----------------------------------------------------------------------------------31

7.3 Keypad Board And Audio board-------------------------------------------------------------------------34

8. Maintainability --------------------------------------------------------------------------------------------------34

8.1 Equipments and Tools Requirements ----------------------------------------------------------------35

8.2 Trouble Shooting ---------------------------------------------------------------------------------------------33

8.2.1 Main Board --------------------------------------------------------------------------------------------------35

8.2.2 Power/Inverter Board -------------------------------------------------------------------------- ----------38

8.2.3 Key Pad Board ---------------------------------------------------------------------------------------------40

9. White-Balance, Luminance adjustment ----------------------------------------------------------------41

10. EDIT Content -------------------------------------------------------------------------------------------42

11. BOM List -------------------------------------- -----------------------------------------------------------------43

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LM-729 Service Manual Rev: A

1.MONITOR SPECIFICATIONS

Driving system TFT Color LCD
LCD Panel Size 43.2cm(17.0")
Pixel pitch 0.264mm( H )x 0.264mm( V )
Viewable angle 90˚ (H) 90˚ (V)
Response time (typ.) 25 ms
Video Analog /Digital
Input Sync. Type H/V TTL
H-Frequency 30kHz – 80kHz
V-Frequency 55-75Hz
Display Colors Over 16 million Colors
Dot Clock 135MHz
Max. Resolution 1280 x 1024
Plug & Play VESA DDC2BTM
Power Consumption ON Mode

OFF Mode
Maximum Screen Size

Power Source
Environmental

Considerations

Weight (N. W.) Packaged 7.0Kg Unit
Unpackaged 6.0Kg Unit

Operating Temp: 0°C to 40°C

<45W
<2W

Horizontal : 13.3”(337.92mm)
Vertical : 10.6”(270.336mm)

100~240VAC,47~63Hz

Storage Temp.: -20°C to 60°C
Operating Humidity : 15% to 90%

Page 6 of 61

LM-729 Service Manual Rev: A

(

2. LCD MONITOR DESCRIPTION

The LCD MONITOR will contain a main board, an inverter/power board, keypad board , Audio board and
external power adapter which house the flat panel control logic, brightness control logic and DDC.
The Inverter board will drive the backlight of panel and the DC-DC conversion.
The Adapter will provide the 12V DC-power to inverter/power board.

Monitor Block Diagram

CCFT Drive.

Flat Panel and
CCFL backlight

Power board

include:adapter,inverter)

Keyboard

Main Board

RS232 Connector
For white balance
adjustment in
factory mode

AC-IN
100V-240V

HOST Computer

Video signal, DDC

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LM-729 Service Manual Rev: A

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:

When the OSD show on screen, Left/Right Button are used to control the monitor functions. Press to switch functions or adjust

settings. And if the OSD off, Left/Right buttons are used to control the audio volume;

- 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.

CONTROL Buttons

A B C D E F

Auto Volume Menu LED Power

A. Menu button

B. Left button/Volume down
C. Right button/Volume up
D. Auto button/Exit
E. Indicator light
F. Power button

3.3 ADJUSTING THE PICTURE

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LM-729 Service Manual Rev: A

OSD Table:

Main

Menu Item

Luminance

Setup

Position

Color

Main

Menu Icon

Sub Menu

Item

Contrast

Brightness

Focus

Clock

H. Position

V. Position

Warm N/A Recall Warm Color

Sub

Menu

Icon

Description

Contrast from Digital-register. 0-100 Recall Cool

Backlight Adjustment 0-100 Recall Cool

Adjust Picture Phase to reduce
Horizontal-Line noise
Adjust picture Clock to reduce
Vertical-Line noise.
Adjust the horizontal position
of the picture.
Adjust the verticalposition of
the picture.

Adjust

Range

0-100 Do Auto Config Image

0-100 Do Auto Config

0-100 Do Auto Config Image

0-100 Do Auto Config

N/A

Reset Value

Contrast Value

Brightness Value

The Color

Temp.

Config

(Analog-On

ly Model)

(Dual-Input

Model)

Cool N/A Recall Cool Color

User / Red

User / Green

User / Blue

Yes

No N/A Do not execute Auto Config,

Analog

Digital N/A Select input signal from digital

N/A Auto Adjust the H/V Position,

N/A Select input signal from analog

Temperature from EEPROM.

Temperature from EEPROM.
Red Gain from
Digital-register.
Green Gain Digital-register. 0-100

Blue Gain from
Digital-register.

Focus and Clock of picture.

return to main menu.

(D-Sub)

N/A

0-100

0-100

N/A N/A Auto

N/A N/A

N/A N/A Input Select

N/A N/A

Temperature will
be set to Cool.

The User R/G/B
value(default is

100) will not be
Modified by Reset
function.

OSD Setup

H. Position

V. Position

OSD Timeout

(DVI)
Adjust the horizontal position
of the OSD.
Adjust the verticalposition of
the OSD.
Adjust the OSD timeout. 10-120 10

Page 9 of 61

0-100 50

0-100 50

LM-729 Service Manual Rev: A

Language

English N/A Set OSD display language to

N/A

The Language will

Information

Deutsch N/A Set OSD display language to

Français N/A Set OSD display language to

Español N/A Set OSD display language to

Italiano N/A Set OSD display language to

简体中文

Information N/A Show the resolution, H/V

Yes N/A Clear each old status of

N/A Set OSD display language to

English.

German.

French.

Spain.

Italian.

Simplified Chinese.

frequency and input port of
current iput timing.

Auto-configuration and set the

be set to English.

N/A

N/A

N/A

N/A

N/A

N/A N/A

N/A N/A Reset

Exit

color temperature to Cool.

No N/A Do not execute reset, return to

main menu.

N/A N/A Exit OSD N/A N/A

N/A N/A

Page 10 of 61

LM-729 Service Manual Rev: A

4. Input/Output Specification

4.1 Input Signal Connector

4.1.1 Analog D-SUB Connector

PIN NO.

1. Red 9. +5V

2. Green 10. Detect Cable

3. Blue 11. NC

4. Ground 12. DDC-Serial Data

5. Ground 13. H-Sync

6. R-Ground 14. V-Sync

7. G-Ground 15. DDC-Serial Clock

8. B-Ground

DESCRIPTION

DESCRIPTION

PI N NO.

VGA connector layout

15
6

11 15

10

4.1.2 DVI-D Connector

DVI-D Connector to be compliant to the latest DVI-DDWG specification version available.

Pin Meaning Pin Meaning Pin Meaning

TMDS Data2-

1
2 TMDS Data2+ 10

TMDS Data 2/4

3

TMDS Data1-

9

TMDS Data1+

17
18

11 TMDS Data 1/3 Shield 19

TMDS Data0-

TMDS Data0+

TMDS Data 0/5 Shield

Shield

not connected

4

5 not connected 13

12 not connected 20 not connected

not connected

21 not connected

6 DDC Clock 14 +5V Power 22 TMDS Clock Shield

7 DDC Data 15 Ground 23 TMDS Clock-

Analogue Vertical

8

Hot Plug Detect

16

24 TMDS Clock+

Sync

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LM-729 Service Manual Rev: A

1
9

17

4.2 Factory Preset Display Modes

VESA MODES

Horizontal Vertical

Mode Resolution Total

640x480@60Hz 800 x 525 31.469 N 59.940 N 25.175

VGA

640x480@72Hz 832 x 520 37.861 N 72.809 N 31.500
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

SVGA

800x600@72Hz 1040 x 666 48.077 P 72.188 P 50.000
800x600@75Hz 1056x625 46.875 P 75.000 P 49.500

1024x768@60Hz 1344x806 48.363 N 60.004 N 65.000

1024x768@60Hz 1312x813 48.78 N 60.00 N 64.000

1024x768@70Hz 1328x806 56.476 N 70.069 N 75.000

XGA

1024x768@72Hz 1304x798 57.515 P 72.074 P 75.000
1024x768@75Hz 1328x804 60.200 N 74.90 N 80.000

1024x768@75Hz 1312x800 60.023 P 75.029 P 78.750

Nominal

Frequency

+/- 0.5kHz

Sync

Polarity

Nominal

Freq.

+/- 1 Hz

Sync

Polarity

Nominal Pixel

Clock

(MHz)

XGA 1152x864@75Hz 1600x900 67.50 P 75.000 P 108.000

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

Nominal

Mode Resolution Total

Nominal

Sync

Frequency

Polarity

+/- 0.5kHz

Nominal

Freq.

+/- 1 Hz

Sync

Polarity

Pixel

Clock

(MHz)

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

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

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LM-729 Service Manual Rev: A

p

4.3 Power Supply Requirements

4.3.1 Input Requirements

PARAMETER RANGE CONDITION

Input AC Voltage 100 to 240VAC RMS Universal input full range
Input Frequency 60Hz @ 100VAC to 50Hz @

240VAC

Input Current Less than 2.0 Amps RMS Input voltage 100 VAC RMS ; 60 Hertz. Parameter
Less than 1.0 Amps RMS Input voltage 220 VAC RMS ; 50 Hertz. Parameter
Input Power Less than 75 Watts

Power factor > 0.5 Input voltage 120 VAC RMS ; 60

Hertz

Inrush Current Less than 30 A peak Input voltage 100 VAC RMS ; 60 Hertz at all
Less than 50 A peak Input voltage 240 VAC RMS ; 50 Hertz at all
Input Fusing Fuse should be located internal to the

adapter, easily accessible when the

cover is removed
Leakage Current Less than 3.5 mA Input voltage 240 Volts RMS ; 50 Hertz
Hi-Pot Primary to secondary 1.5KVAC for 1 Minute(leakage current 10mA)

Prima1ry to Safety Ground 1.5KVAC for 1 Minute(leakage current 10mA)

must be reached within 3 seconds of turn-on.
must be reached within 3 seconds of turn-on.

Phase(0, 90, 180, 270 degree)
Phase(0, 90, 180, 270 degree)

Fuse must be UL/CSA approved. Fuse value must no
have to change for 115 VAC or 230 VAC operation

1.8KVAC for 1 Minute(leakage current 10mA)

3.0KVAC for 1 Minute(leakage current 10mA)
without Y-cap & Coupling cap.

1.8KVAC for 1 Minute(leakage current 10mA)

4.3.2 Output Requirements
PARAMETER RANGE CONDITION

DC Out 12VDC ± 5% Min 0A Max 3.75A
Load Regulation 12.0V(12.12V) ± 5% 11.4 to 12.6VDC
Dynamic Load
Regulation
Ripple & noise 170mVpp at 12VDC Input voltage : 100VAC at 60Hz 240VAC at 50Hz

Output current

rotection
Leakage Current Less than 0.25 mA Input voltage 100 Volts RMS ; 50 Hertz
Less than 0.5 mA Input voltage 240 Volts RMS ; 50 Hertz

Any frequency up to 250Hz(duty
50%)

less than 7.0A, more than 12.0A
at 12.0VDC

±5% for 10% to 100%, 100% to 10% load change for
+12Vdc

* Ripple and noise are measured.
Current exceeds maximum rateing more than 20%

Page 13 of 61

LM-729 Service Manual Rev: A

4.4 PANEL SPECIFICATION

4.4.1 Panel Feature

-High contrast ratio, high aperture structure

-TN(Twisted Nematic) mode

-Wide viewing angle

-High speed response

-SXGA(1280 x 1024 pixels) resolution

-Low power consumption

-2 dual CCFTs(Cold Cathode Fluorescent Tube)

-DE(Data Enable) mode

-COMPACT SIZE DESIGN

4.4.2 Display Characteristics

Items Specification Unit

Display Area 337.92(H) x 270.336(V) mm
Driver element a-Si TFT active matrix
Display color 16.2M Colors
Number of pixels 1280 x 1024 pixel
Pixel Arrangement RGB vertical stripe
Pixel pitch 0.264(H) x 0.264(W) mm
Display Mode Normally White

4.4.3 Optical Characteristics

The optical characteristics are measured under stable conditions at 25℃ (Room Temperature):

Item Symbol Conditions Min. Typ. Max. Unit Note

Contrast Ratio
(Center of screen)

Response
Time

Luminance of White
(Center of screen)

Chromaticity

Coordinates (CIE)

Brightness Uniformity [%] 75 80 -

Rising
Falling Tf - 12 20

Color

(CIE 1931)

C/R 250 450 -

Tr

YL 200 260 - Cd/m2
Rx 0.64

Ry 0.34
Gx 0.29

Gy 0.61
Bx 0.14

By 0.07
Wx 0.31
Wy

Normal

ψ=0
θ=0

Viewing

Angle

- 4 5

Typ.

-0.03

0.33

TYP.

+0.03

msec

Page 14 of 61

LM-729 Service Manual Rev: A

4.4.4 Parameter guide line for CCFL Inverter

INVERTERMAXBRINGTHNESS(Vadj:5.0v),LOAD=120KΩX4(ROOMTEMPERATURE25℃ ±4℃)

ITEM SYMBOL MIN. TYP. MAX. UNIT REMARK

Inputvoltage Vin  10.8 12 13.2 V

Inputcurrent Iin2250 2500 mA FOR4LOAD

OutputCurrent Iout 6.0 6.5 7.0 mA FOR1LOAD

Frequency

F 50.0 55.0 60.0 KHZ

FOR1LOAD

H.Vopen Vopen 1450 1600 1750 Vrms NOLOAD

H.VLoad Vload 710 810 910 Vrms

Startvoltage Vst

Protectdelaytime PDT



INVERTERMINBRINGTHNESS(Vadj:0.0v),LOAD=120KΩX4(ROOMTEMPERATURE25℃ ±4℃)

1650 1750 1850 Vrms RL=CCFL

0.4 1 4 Sec

RL=120KΩ

ITEM SYMBOL MIN. TYP. MAX. UNIT REMARK

inputvoltage Vin  10.8 12 13.2 V

inputcurrent Iin660 750 mA FOR4LOAD

OutputCurrent Iout 3.0 3.5 4.0 mA FOR1LOAD

Frequency

F 50.0 55.0 60.0 KHZ

FOR1LOAD

H.Vopen Vopen 1450 1600 1750 Vrms NOLOAD

Startvoltage Vst

H.VLoad Vload 350 450 550 Vrms

1650 1750 1850 Vrms RL=CCFL

RL=120KΩ

Page 15 of 61

LM-729 Service Manual Rev: A

5. Block Diagram

5.1 Monitor Exploded View

Page 16 of 61

LM-729 Service Manual Rev: A

2

10

12

643

8

9

141113

1

16

1719

18

5.2 Software Flow Chart

1

Y

N

N

5

N

Y

7

N

Y

N

Y

N

Y

Y

N

5

Y

N

Y

Page 17 of 61

LM-729 Service Manual Rev: A

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 ?

1 1 ) Update the life time of back light.

12) Check the analog port, are there any signals coming ?

13) Does the scalar send out a 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 ?

Page 18 of 61

LM-729 Service Manual Rev: A

5.3 Electrical Block Diagram

5.3.1 Main Board

LCD

Interface

(CN4/CN5)

Flash Memory

W39f010P-70B

(U6)

OSD

Control

Interface

(CN9)

EPR_SDA
EPR_SCL

EEPROM

24C16

(U7)

RXD
TXD

Connector

DB15_SDA,
DB15_SCL

EEPROM

Scalar gm5126/gm2126

(Include MCU,ADC,OSD)

(U4)

RGB

Hsync,
Vsync

D-Sub

(CN2)

24C02

(U2)

DVI-I only
Connector
(CN1)

EEPROM (D-I only)

24C02
(U1)

Page 19 of 61