Samsung ltp227w service manual

TFT-LCD TV/MONITOR

Chassis Model VR22UO LTP227W

SERVICE

Manual

TFT-LCD TV/MONITOR CONTENTS

1. Precautions

2. Product Specifications

3. Disassembly & Reassembly

4. Alignment & Adjustments

5. Troubleshooting

6. Exploded View & Parts List

7. Parts List

8. Block Diagram

9. Wiring Diagram

10. PCB Layout

11. Schematic Diagrams

12. Panel Description

❈ This Service Manual is a property of Samsung

Electronics Co., Ltd. Any unauthorized use of Manual can be punished under applicable International and/or domestic law.

Samsung Electronics Co.,Ltd.

416, Maetan-3Dong, Yeongtong-Gu, Suwon City, Kyungki-Do, Korea, 442-742 Printed in Korea P/N : BN82-00103E-00 http : //www.samsungmonitor.com (SyncMaster Worldwide) http : //www.samsung-monitor.com (SyncMaster USA) URL : http://itself.sec.samsung.co.kr/

1 Precautions

DEVICE UNDER TEST

TEST ALL

EXPOSED METAL

SURFACES

(READING SHOULD

NOT BE ABOVE 0.5mA)

LEAKAGE CURRENT

TESTER

2-WIRE CORD

ALSO TEST WITH

PLUG REVERSED (USING AC ADAPTER PLUG AS REQUIRED)

EARTH

GROUND

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

1-1 Safety Precautions

1-1-1 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 Servicing 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 resistor-capacitor 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 safety-related 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.

LTP227W 1-1

1 Precautions

1-2 Servicing 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.

1-2-1 General Servicing 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.

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.

1-3 Electrostatically Sensitive Devices (ESD) 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. 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 wriststrap 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.

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.

1-2 LTP227W

2 Product Specifications

2-1 Specifications

Item

LCD Panel TFT-LCD Panel, RGB vertical stripe, normaly Black, 22-Inch viewable, 0.381 mm pixel pitch

Scanning Frequency Horizontal : 30 kHz ~ 68 kHz (Automatic)

Vertical : 56 Hz ~ 85 Hz (Automatic)

Display Colors 16.7 Million colors

Maximum Resolution Horizontal : 1280 Pixels

Vertical : 720 Pixel

Input Video Signal Positive at 75 Ω

Input Sync Signal Type : Seperate H/V

Level : TTL level

Maximum Pixel Clock rate 70 MHz

Active Display Horizontal/Vertical

AC power voltage & Frequency

Power Consumption 80 W

Dimensions (W x H x D) Set

Package

487.68 mm/ 274.32 mm

AC 100 ~ 264 Volts, 50~60 Hz ± 3 Hz

23.6 x 17.3 x 8.2 Inches (599 X 439 X 209.4 mm) / 23.6 x 16.5 x 4.4 Inches (599 X 418 X 112.7 mm) State of stand disassembled

28.1 x 23.0 x 8.1 Inches (713.0 X 583.0 X 205.0 mm)

Description

Weight

Set / Package 8.98 kg (19.8 lbs) After installation of Stand / 11.0 kg (24.3 lbs)

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 %

Tunning Frequency Synthesize

TV System

Antena Input 75Ω

– MAX Internal speaker Out : Right => 5W

Sound Characteristic

– BASS Control Range : -8 dB ~ + 8dB – TREBLE Control Range : -8 dB ~ +8 dB – Headphone Out : 5 mW max (400 m Vrms) – Output Frequency : 20 Hz ~15.2 Hz

System NTSC-M

Sound STEREO

Left => 5W

LTP227W 2-1

2 Product Specifications

12 34 56 78

9 10111213141516

17 18 19 20 21 22 23 24

C1 C2

2-2 Pin Assignments

2-2-1 DVI-I (Analog & Digital)

Ref) DVI-D : Digital only

D-SUB : Analog only

DVI-I Receptacle Connector Front View

Pin No.

Signal Assignment

RX2-

RX2+

GND

DDC Clock (SCL)

DDC Data (SDA)

Analog Vertical Sync.

RX1-

RX1+

Pin No.

Signal Assignment

GND

DDC Input Power(+5V)

IDENT_PC

RX0-

RX0+

GND

Pin No.

Signal Assignment

GND

RXC+

RXC-

Analog Red

Analog Green

Analog Blue

Analog Horizontal Sync.

2-2 LTP227W

2 Product Specifications

2-2-2 Component 1, 2

RCA Green

RCA Blue

RCA Red

RCA White

RCA Red

GND

Pb (Cb)

GND

Pr (Cr)

GND

Audio L

GND

Audio R

GND

2-2-3 S-Video

1 2 3 4 5

Separate

GND

C GND GND

2-2-4 A/V

RCA Yellow

RCA White

RCA Red

CVBS

Audio L

GND

Audio R

GND

LTP227W 2-3

2 Product Specifications

2-3 Timing Chart

This section of the service manual describes the timing that the computer industry recognizes as standard for computer-generated video signals.

2-3-1 LCD Panel Mode1 mode

2-4 LTP227W

2-3-1 Supported Modes (1)

2 Product Specifications

LTP227W 2-5

2 Product Specifications

2-3-1 Supported Modes (2)

2-6 LTP227W

2-3-1 Supported Modes (3)

2 Product Specifications

LTP227W 2-7

2 Product Specifications

Memo

2-8 LTP227W

3 Disassembly and Reassembly

This section of the service manual describes the disassembly and reassembly procedures for the LTP227W monitor.

WARNING: This monitor contains electrostatically sensitive devices. Use caution when handling

these components.

3-1 Disassembly

Cautions : 1. Disconnect the monitor from the power source before disassembly.

2. Follow these directions carefully; never use metal instruments to pry apart the cabinet.

3. R/Cover opening jig : BH81-00001A

1. Loacte the monitor on the cushioned table with face down. Remove the stand from LCD-TV and pull the stand cover.

2. Remove 2 screws from the rear cover and remove rear cover by using opening jig.

SPEAKER

A/V INPUT

FUNCTION

3. Lift up the rear cover and disconnect function

cable, A/V Input cable, IR cable and speaker cable from the shield. (See illustrations)

4. Remove 2 screws (A/V Input Board) from the

shield. Please add a circle around the 6 screw that connects the silver shield of the Main-PCB to the Panel shield.(see illustrations)

5. Lift up main shield and remove 17 screws from

the set (Main Board and Panel Shield). (see illustrations)

LTP227W 3-1

3 Disassembly and Reassembly

3-2 Replacement Order of Lamp Assemblies

6. Disconnect cable and lift up the main board and panel shield. (see illustrations)

7. Lift up the panel.

LCD panal may not be serviced. (Lamps are generally located at top and bottom of panel, which may be replaced.However,for the Victoria LTA170WP_L01 panel, the lamp is firmly soldered inside of the back panel. Therefore,servicing the lamp may cause a defective panel.Also,servicing lamp requires front glass removal, which may cause scratch and/or foreign materials on the glass.)

3-3 Reassembly

Reassembly procedures are in the reverse order of dissasembly procedures.

3-2 LTP227W

4 Alignments and Adjustments

4-1 General Alignment Instuction

1. Usually, a color TV-VCR needs only slight touch-up adjustment upon installation.

Check the basic characteristics such as height, horizontal and vertical sync.

2. Use the specified test equipment or its equivalent.

3. Correct impedance matching is essential.

4. Avoid overload. Excessive signal from a sweep generator might overload the front-end

of the TV. When inserting signal markers, do not allow the marker generator to distort

test result.

5. Connect the TV only to an AC power source with voltage and frequency as specified on

the backcover nameplate.

6. Do not attempt to connect or disconnect any wire while the TV is turned on. Make sure

that the power cord is disconnected before replacing any parts.

7. To protect aganist shock hazard, use an isolation transform.

LTP227W 4-1

4 Alignments and Adjustments

4-2 Factory Mode Adjustments

4-2-1 Entering Factory Mode

1. To enter “Service Mode” Press the remote -control keys in this sequence :

- If you do not have Factory remote - control

- If you have Factory remote - control

- The buttons are active in the service mode.

1. Remote - Control Key : Power, Arrow Up, Arrow Down, Arrow Left

Arrow Right, Menu, Enter, Number Key(0~9)

2. Function - Control Key : Power, CH +, CH -, VOL +, VOL -,

Menu, TV/VIDEO(Enter)

4-2-2 Factory Mode Tree

4-2 LTP227W

4 Alignments and Adjustments

LTP227W 4-3

4 Alignments and Adjustments

4-4 LTP227W

4 Alignments and Adjustments

LTP227W 4-5

4 Alignments and Adjustments

4-6 LTP227W

4 Alignments and Adjustments

LTP227W 4-7

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