Samsung 940MW, 940MG Schematic

SERVICE

Manual

LCD Monitor

Fashion Feature

LCD-Monitor

Chassis LDO19WS

LDO19CS

Model 940MW

940MG

- MFM Model

- VCT49xy

- W/W model

- High Contrast Ratio(700:1)

- High Luminance(300cd/m2)

photocopied, reproduced, translated, or converted to any electronic or machine readable form without prior written permission of Samsung Electronics Co., Ltd.

LDO19WS Service Manual First edition September 2005.

Printed in Korea.

Trademarks

Samsung is the registered trademark of Samsung Electronics Co., Ltd.

LDO19WS and MacMaster Cable Adapter are trademarks of Samsung Electronics Co., Ltd.

Macintosh, Power Macintosh are trademarks of Apple Computer, Inc.

All other trademarks are the property of their respective owners.

11. Precautions

………………………………………………………………………………………………………………………………………

11-1

1-1. Safety Precautions ………………………………………………………………………………………………………………………1-1

1-2. Servicing Precautions ……………………………………………………………………………………………………………………1-2

1-3. Static Electricity Precautions ……………………………………………………………………………………………………………1-2

1-4. Install Precautions …………………………………………………………………………………………………………………………1-3

2. Product specifications

…………………………………………………………………………………………………………………………

22-1

2-1. Fashion Feature ………………………………………………………………………………………………………………………… 2-1

2-2. Specifications Comparison to the Old Model …………………………………………………………………………………………2-1

2-3. Specifications ………………………………………………………………………………………………………………………………2-2

2-4. Option Specification ………………………………………………………………………………………………………………………2-3

3. Alignments and Adjustments

…………………………………………………………………………………………………………………

33-1

3-1. Program Upgrade …………………………………………………………………………………………………………………………3-1

3-2. DDC JIG Installation ……………………………………………………………………………………………………………………3-2

3-3. EDID Installation with Windows Program ………………………………………………………………………………………………3-3

3-4. Factory Mode Adjustments ………………………………………………………………………………………………………………3-4

4. Troubleshooting

………………………………………………………………………………………………………………………………

44-1

4-1. No Power

………………………………………………………………………………………………………………………………… 4-1

4-2. No Picture (PC Signal) ………………………………………………………………………………………………………………… 4-2

4-3. No Picture (TV)

…………………………………………………………………………………………………………………………… 4-4

4-4. No Picture (Video/S-Video/Scart)

……………………………………………………………………………………………………… 4-6

4-5. No Picture (Component) ………………………………………………………………………………………………………………… 4-8

4-6. No Sound (TV) ………………………………………………………………………………………………………………………… 4-10

4-7. No Sound (Component) ……………………………………………………………………………………………………………… 4-12

5. Exploded View and Parts List

…………………………………………………………………………………………………………………

55-1

6. EElectrical Parts List

……………………………………………………………………………………………………………………………

66-1

7. BBlock Diagram

…………………………………………………………………………………………………………………………………

77-1

8. WWiring Diagram

…………………………………………………………………………………………………………………………………

88-1

9. SSchematic Diagrams

……………………………………………………………………………………………………………………………

99-1

Contents

110. Operating Instructions and Installation

……………………………………………………………………………………………………

110-1

10-1. Front …………………………………………………………………………………………………………………………………… 10-1

10-2. Rear …………………………………………………………………………………………………………………………………… 10-2

10-3. Remote Control ……………………………………………………………………………………………………………………… 10-5

11. Disassembly and Reassembly

………………………………………………………………………………………………………………

111-1

11-1. Disassembly …………………………………………………………………………………………………………………………… 11-1

11-3. Reassembly …………………………………………………………………………………………………………………………… 11-3

12. PCB Diagram

…………………………………………………………………………………………………………………………………

112-1

13. CCircuit Descriptions

……………………………………………………………………………………………………………………………

113-1

13-1. Block description ……………………………………………………………………………………………………………………… 13-1

14. Reference Infomation

…………………………………………………………………………………………………………………………

114-1

14-1. Technical Terms ……………………………………………………………………………………………………………………… 14-1

14-2. Connecting Your Monitor …………………………………………………………………………………………………………… 14-4

14-3. Connecting to Others devices ……………………………………………………………………………………………………… 14-5

14-4. Pin Assignment ……………………………………………………………………………………………………………………… 14-8

14-5. Timing Chart …………………………………………………………………………………………………………………………… 14-9

14-6. Preset Timing Modes ……………………………………………………………………………………………………………… 14-10

14-7. Panel Description …………………………………………………………………………………………………………………… 14-11

Contents

1 Precautions

1-1

1-1-1 Warnings

1. For continued safety, do not attempt to modify the circuit board.

2. Disconnect the AC power and DC power jack before servicing.

1-1-2

Ser vicing the LCD Monitor

1. When servicing the LCD Monitor, Disconnect the AC line cord from the AC outlet.

2. It is essential that service technicians have an accurate voltage meter available at all times. Check the calibration of this meter periodically.

1-1-3 Fire and Shock Hazard

Before returning the monitor to the user, perform the following safety checks:

1. Inspect each lead dress to make certain that the leads are not pinched or that hardware is not lodged between the chassis and other metal parts in the monitor.

2. Inspect all protective devices such as nonmetallic control knobs, insulating materials, cabinet backs, adjustment and compartment covers or shields, isolation resistorcapacitor networks, mechanical insulators, etc.

3. Leakage Current Hot Check (Figure 1-1):

WARNING : Do not use an isolation

transformer during this test.

Use a leakage current tester or a metering system that complies with American National Standards Institute (ANSI C101.1, Leakage Current for Appliances), and Underwriters Laboratories (UL Publication UL1410,

59.7).

Figure 1-1. Leakage Current Test Circuit

4. With the unit completely reassembled, plug the AC line cord directly into a 120V AC outlet. With the unit’s AC switch first in the ON position and then OFF, measure the current between a known earth ground (metal water pipe, conduit, etc.) and all exposed metal parts, including: metal cabinets, screwheads and control shafts. The current measured should not exceed 0.5 milliamp. Reverse the power-plug prongs in the AC outlet and

repeat the test.

1-1-4 Product Safety Notices

Some electrical and mechanical parts have special safetyrelated characteristics which are often not evident from visual inspection. The protection they give may not be obtained by replacing them with components rated for higher voltage, wattage, etc. Parts that have special safety characteristics are identified by on schematics and parts lists. A substitute replacement that does not have the same safety characteristics as the recommended replacement part might create shock, fire and/or other hazards. Product safety is under review continuously and new instructions are issued whenever appropriate.

1 Precautions

Follow these safety, servicing and ESD precautions to prevent damage and to protect against potential hazards such as electrical shock.

1-1 Safety Precautions

1 Precautions

1-2

1-2-1 General Ser vicing

Precautions

1. Always unplug the unit’s AC power cord from the AC power source and disconnect the DC Power Jack before attempting to: (a) remove or reinstall any component or assembly, (b) disconnect PCB plugs or connectors, (c) connect a test component in parallel with an electrolytic capacitor.

2. Some components are raised above the printed circuit board for safety. An insulation tube or tape is sometimes used. The internal wiring is sometimes clamped to prevent contact with thermally hot components. Reinstall all such elements to their original position.

3. After servicing, always check that the screws, components and wiring have been correctly reinstalled. Make sure that the area around the serviced part has not been damaged.

1. Immediately before handling any semiconductor components or assemblies, drain the electrostatic charge from your body by touching a known earth ground. Alternatively, wear a discharging wrist-strap device. To avoid a shock hazard, be sure to remove the wrist strap before applying power to the monitor.

2. After removing an ESD-equipped assembly, place it on a conductive surface such as aluminum foil to prevent accumulation of an electrostatic charge.

3. Do not use freon-propelled chemicals. These can generate electrical charges sufficient to damage ESDs.

4. Use only a grounded-tip soldering iron to solder or desolder ESDs.

5. Use only an anti-static solder removal device. Some solder removal devices not classified as “anti-static” can generate electrical charges sufficient to damage ESDs.

4. Check the insulation between the blades of the AC plug and accessible conductive parts (examples: metal panels, input terminals and earphone jacks).

5. Insulation Checking Procedure: Disconnect the power cord from the AC source and turn the power switch ON. Connect an insulation resistance meter (500 V) to the blades of the AC plug.

The insulation resistance between each blade of the AC plug and accessible conductive parts (see above) should be greater than 1 megohm.

6. Always connect a test instrument’s ground lead to the instrument chassis ground before connecting the positive lead; always remove the instrument’s ground lead last.

6. Do not remove a replacement ESD from its protective package until you are ready to install it. Most replacement ESDs are packaged with leads that are electrically shorted together by conductive foam, aluminum foil or other conductive materials.

7. Immediately before removing the protective material from the leads of a replacement ESD, touch the protective material to the chassis or circuit assembly into which the device will be installed.

Caution:Be sure no power is applied to the

chassis or circuit and observe all other safety precautions.

8. Minimize body motions when handling unpackaged replacement ESDs. Motions such as brushing clothes together, or lifting your foot from a carpeted floor can generate enough static electricity to damage an ESD.

1-3 Static Electricity Precautions

Some semiconductor (solid state) devices can be easily damaged by static electricity. Such components are commonly called Electrostatically Sensitive Devices (ESD). Examples of typical ESD are integrated circuits and some field-effect transistors. The following techniques will reduce the incidence of component damage caused by static electricity.

1-2 Ser vicing Precautions

WARNING: An electrolytic capacitor installed with the wrong polarity might explode. Caution: Before servicing units covered by this service manual, read and follow the Safety Precautions section

of this manual.

Note: If unforeseen circumstances create conflict between the following servicing precautions and any of the safety

precautions, always follow the safety precautions.

1 Precautions

1-3

1. For safety reasons, more than two people are required for carrying the product.

2. Keep the power cord away from any heat emitting devices, as a melted covering may cause fire or electric shock.

3. Do not place the product in areas with poor ventilation such as a bookshelf or closet. The increased internal temperature may cause fire.

4. Bend the external antenna cable when connecting it to the product. This is a measure to protect it from being exposed to moisture. Otherwise, it may cause a fire or electric shock.

5. Make sure to turn the power off and unplug the power cord from the outlet before repositioning the product. Also check the antenna cable or the external connectors if they are fully unplugged. Damage to the cord may cause fire or electric shock.

6. Keep the antenna far away from any high-voltage cables and install it firmly. Contact with the highvoltage cable or the antenna falling over may cause fire or electric shock.

7. When installing the product, leave enough space (10cm) between the product and the wall for ventilation purposes. A rise in temperature within the product may cause fire.

1-4 Installation Precautions

Memo

1 Precautions

1-4

2 Product Specifications

2-1

2 Product Specifications

2-1 Fashion Feature

- MFM Model

- VCT49xy

- W/W model

- High Contrast Ratio(700:1)

- High Luminance(300cd/m2)

2-2 Specifications Comparison to the Old Model

Model LDO19WS / LDO19CS MH17ES Area World Wide China / East-South

Asia

Panel LTM190M2-L01 EU-L21 Response Time 8ms 8ms Scart Jack OX Micom VCT49xy (Embeded MCU) TDA15021H Scaler SE6181 TSU396AWJ-LF

PBA

2 Product Specifications

2-2

LCD Panel

TFT-LCD panel, RGB vertical stripe, normaly white, 19-Inch viewable, 0.2835mm pixel pitch

Scanning Frequency 30 kHz ~ 81 kHz(Automatic)

Display Colors 16.7 Million colors

Maximum Resolution Horizontal:1440 Pixels

Vertical: 900 Pixels

Input Video Signal Analog, 0.7 Vp-p ± 1% positive at 75 Ω, internally terminated, DVI

Input Sync Signal Type: Seperate H/V automatic synchronization

without external switch of sync type, Composite

Level: TTL level

Maximum Pixel Clock rate

140 MHz

Active Display Horizontal/Vertical 408.24(H) x 255.15(V)

AC power voltage & Frequency

AC 100 ~ 240 Volts (± 10%), 60/ 50 Hz ± 3 Hz

Power Consumption 55 W (max)

Dimensions Set (W x H x D) 18.3 x 16.0 x 8.5 Inches (466 X 406 X 217 mm)

Weight (Set/Package) 6.2 kg (14 Ibs)

TV / Video Color system : NTSC, PAL, SAM, PAL-M/N, NT43, PAL60

Sound system : B/G, I, D/K

Antena Input 75Ω, Coaxial Cable

Environmental Considerations

Operating Temperature : 50°F ~ 104°F (10°C ~ 40°C)

Operating Humidity : 10 % ~ 80 %

Storage Temperature : -4°F ~ 113°F (-20°C ~ 45°C)

Storage Humidity : 5 % ~ 95 %

• Designs and specifications are subject to change without prior notice.

2-3 Specifications

Item

Description

2 Product Specifications

2-3

2-4 Option Specification

Item Item Name CODE.NO Remark

Quick Setup Guide

BH68-00376L

BH68-70438A

BN59-00480D (940MW) BN59-00480W (940MG)

BN39-00244B

BN39-00061B

3903-000042

Warranty Card

(Not available in all locations)

User's Guide, Monitor

Driver, Natural Color

software

D-Sub(15 Pin)

Cable

Audio Cable

Power Cord

BN59-00434C

4301-000121

3705-001191

Remote Control

Batteries (AAA X 2)

Connecter

Memo

2 Product Specifications

2-4

3 Alignments and Adjustments

3-1

3 Alignments and Adjustments

This section describes to adjust LCD monitor after replacing EEPROM, Main PBA or Panel.

3-1 Progr am Upgr ade

Change MICOM

: If the similer happenings occur, EEPROM can be changed

-. EX1) When screen appears but remote control and function key aren't working

-. EX2) When LED is on but the screen doesn't appear

-. EX3) After mass production, when the micom program version is up-graded * MICOM replacement can be done when Service Bulletin issue is in practice.

The process of working need to be prepare on Service Bulletin.

As the visual sample shown, after disassembling the set (refer to SET disassemble), remove the Micom in the exist IC202 Socket and replace new Micom.

- Use appropriate JIG or any sharp tool and place in the both corners to assist in removing. (Be aware! If the socket cause any damage after replacement the monitor will not function properly.)

- When inserting, attend to IC No.1 direction and press with suitable amount of strength.

- After replacement, in case of EEPROM Clear, enter to Factory mode and perform into action.

3 Alignments and Adjustments

3-2

PC parallel port ----- DDC JIG ----- Monitor

JIG cable

D_sub cable

Connect DDC JIG.

3-2 DDC JIG installation

3 Alignments and Adjustments

3-3

3-3 EDID Installation with Windows Progr am

1. Execute "WinDDC.exe"

2. Click "Sys Config" Select "Station : Write station" Check "Serial No and Week : Don't change" Click "Save"

3. Click "Open" icon. Select "Connected Port #1" and Next "OK". * File Name - SM940MWA.DDC : Analog

- SM940MWD.DDC : Digital

Press enter key on your keyboard.

4. Confirm the "DDC OK".

- After Replacing the Main Board

- EDID Installation (Analog and Digital)

3 Alignments and Adjustments

3-4

3-4 Factory Mode Adjustments

3-4-1 Factory Mode Admission

- PAL :

- NTC :

InfoPower off Menu Power on

MUTEPower off 1 8 2 Power on

3-4-2 Ser vice Mode Menu

-. DDP Part

3 Alignments and Adjustments

3-5

-. MSTAR Part

-. Adjust , PC/DTV Auto Color

3 Alignments and Adjustments

3-6

-. Pre-Setting, Options , Checksum

-. Panel Information , Reset

4 Troubleshooting

4-1

4 Troubleshooting

4-1 No Power

Does DC 13V, 5V

appear at CN400?

Check Inverter/Adaptor Board

Yes

Does DC 3.3V

Appear at FT412?

Check circuits related

to IC405.

Check IC702(VCTI-F2), IC704,

and IC301(SE6181LA).

Yes

Does DC 3.3V

Appear at FT414?

Check circuits related to

IC407.

4 Troubleshooting

4-2

4-2 No Video (PC Signal)

Power Indicator is green

Does a signal appear at

C103,C104 and C105

(R,G,B input?)

Check circutis relatedCN101.

Yes

Does a signal appear at

R108 and R110(H/V Sync)?

Check circuits related CN101.

Yes

Does a signal appear at

1~30 of CN300(LVDS out)?

Check circuits related IC031.

Yes

Replace LCD PANEL.

2 3

4 Troubleshooting

4-3

WAVEFORMS

1 2

4 Troubleshooting

4-4

4-3 No Picture (TV)

Does a signal appear at

PIN 2 of FT702 (X6966)?

Check TU700(TUNER).

Yes

Does a signal appear at

PIN71,72,73,74,75,78,79,80

of IC702?

Check the circuits related to

IC702.

Yes

Does a signal appear at

PIN 1~30 of CN300?

Check IC301.

Replace LCD Panel.

4 Troubleshooting

4-5

WAVEFORMS

4 5

4 Troubleshooting

4-6

4-4 No Picture (Video/S-VIDEO/SCART )

Power Indicator is off.

Lamp on, no picture.

Dose the signal appear at

R732,R733,R734

Check a A/V cable and

video signal.

Yes

Does the signal appear at

PIN(71:80) of IC703?

Check a connection harness.

Yes

Check a LVDS cable?

Replace lcd panel?

Check a IC301.

Change a main PCB ass'y.

Does the digital data

appear at output of LVDS

(RA301~RA303)?

Check a IC703.

Change a main PCB ass'y.

Yes

4 Troubleshooting

4-7

WAVEFORMS

4 5

4 Troubleshooting

4-8

4-5 No Picture (COMPONENT)

Power Indicator is off.

Lamp on, no picture.

Does the signal appear at

PIN(31:37) of IC301?

Check a A/V cable and

video signal.

Yes

Does the digital data

appear at output of LVDS

(RA301~RA303)?

Check a connection harness.

Yes

Check a LVDS cable?

Replace lcd panel?

Check a IC301.

Change a main PCB ass'y.

4 Troubleshooting

4-9

WAVEFORMS

4 5

+ 60 hidden pages