Samsung GH15ES, GH15LS, GH15MS User Manual

TFT-LCD MONITOR

GH15LS GH15ES GH15MS

SERVICE

Manual

TFT-LCD MONITOR CONTENTS

1. Precautions

2. Product Specifications

3. Disassembly & Reassembly

4. Troubleshooting

5. Exploded View & Parts List

GH15LS/GH15ES

6. Electrical Parts List

7. Block Diagram

8. Wiring Diagram

9. Schematic Diagrams

GH15MS

10. Panel Description

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.

3. When the chassis is operating, semiconductor heatsinks are potential shock hazards.

1-1-2 Servicing the LCD Monitor

1. When servicing the LCD Monitor, remove the static charge by connecting a 10k ohm resistor in series with an insulated wire (such as a test probe) between the chassis and the anode lead. (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).

4. With the unit completely reassembled, plug the AC

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

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.

Figure 1-1. Leakage Current Test Circuit

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.

on schematics and parts lists. A substitute

GH15LS/GH15ES/GH15MS 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 devices are integrated circuits and some fieldeffect 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 GH15LS/GH15ES/GH15MS

2 Product Specifications

2-1 Specifications

Item

GH15LS/GH15ES GH15MS

LCD Panel TFT-LCD panel, RGB vertical stripe, normaly white, 15-Inch viewable,

0.297 (H) pixel pitch

Scanning Frequency Horizontal : 30 kHz ~ 61 kHz (Referring ~ Timing chart, Page 2-3, 2-4)

Vertical : 50 Hz ~ 75 Hz (Referring ~ Timing chart, Page 2-3, 2-4)

Display Colors 16,003,008 colors

Maximum Resolution Horizontal : 1024 Pixels Vertical : 768 Pixels

Input Video Signal Analog, 0.714 Vp-p ± 5% positive at 75 Ω, internally terminated

Input Sync Signal Type: Seperate H/V sync, Composite H/V, Sync-on-Green, automatic synchronization

without external switch of sync type

Level: TTL level

Maximum Pixel Clock rate 80 MHz

Active Display Horizontal/Vertical 304.1 mm / 228.1 mm

AC power voltage & Frequency AC 90 ~ 264 Volts, 60/50 Hz ~ 12V/3A

Power Consumption 25 W (normal)

Description

Dimensions Unit (W x D x H) With Simple Stand Without Simple stand With Pivot Stand

Without Pivot Stand

Weight (Net/Gross) 4.2 kg (9.3 lbs) / 5.2 kg (11.5 lbs) 4.3 kg (9.5 lbs) / 5.5 kg (12.1 lbs)

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

Audio Characteristics (GH15MS) • Built-in Microphone: High-sensitivity condenser microphone (mono)

•GH15LS/GH15ES/GH15MS complies with SWEDAC (MPR II) recommendations for reduced electromagnetic fields.

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

15.4 x 15.1 x 6.8 Inches (391.4 x 383.6 x 173 mm) 16.5 x 15.2 x 6.8 Inches (417.9 x 386.1 x 173 mm)

15.4 x 11.5 x 2.5 Inches (391.4 x 292.8 x 64.0 mm) 16.5 x 11.7 x 2.5 Inches (417.9 x 297.9 x 64.2 mm)

15.4 x 15.1 x 6.8 Inches (391.4 x 383.6 x 173 mm) 16.5 x 15.2 x 6.8 Inches (417.9 x 386.1 x 173 mm)

15.4 x 17.1 x 6.8 Inches (391.4 x 433.6 x 173 mm) 16.5 x 17.2 x 6.8 Inches (417.9 x 436.1 x 173 mm)

15.4 x 11.5 x 2.5 Inches (391.4 x 292.8 x 64.0 mm) 16.5 x 11.7 x 2.5 Inches (417.9 x 297.9 x 64.2 mm)

Humidity : 10 % ~ 80 % Storage Temperature : 13 °F ~ 113 °F (-25 °C ~ 45 °C) Humidity : 5 % ~ 95 %

• Audio input: Left/Right Stereo phone jack, 0.5 Vrms

• Sound output: 1.0 W (left) + 1.0 W (right)/THD 1% at 8ohm

• Frequency response: 80 Hz~20 kHz (at –3dB)

• Headphone: Max 50mW output (3.5-pi jack)

• Speaker: Internal semi Dome (16ohm x 2)

GH15LS/GH15ES/GH15MS 2-1

2 Product Specifications

2-2 Pin Assignments

Pin No.

10 11 12 13 14 15

Sync Type

Separate Composite Sync-on-green

1 2 3 4 5 6 7 8 9

Red Green Blue GND GND (DDC Return) GND-R GND-G GND-B No Connection GND-Sync./Self Test GND DDC Data H-Sync. V-Sync. DDC Clock

15-Pin Signal Cable Connector

Red Green Blue GND GND (DDC Return) GND-R GND-G GND-B No Connection GND-Sync./Self Test GND DDC Data H/V-Sync. Not Used DDC Clock

Red Green + H/V Sync. Blue GND GND (DDC Return) GND-R GND-G GND-B Not Used GND-Sync./Self Test GND DDC Data Not Used Not Used DDC Clock

2-2 GH15LS/GH15ES/GH15MS

2 Product Specifications

QRS

Video

Sync

Horizontal

Vertical

CDE

Video

Sync

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.

Table 2-1. Timing Chart

Mode

IBM

VESA

Timing

fH (kHz)

A µsec

B µsec

C µsec

D µsec

E µsec

fV (Hz)

O msec

P msec

Q msec

R msec

S msec

Clock Frequency (MHz)

VGA1/70 Hz

640 x 350

31.469

31.778

3.813

1.589

26.058

0.318

70.086

14.268

0.064

1.716

11.504

0.985

25.175

VGA2/70 Hz

720 x 400

31.469

31.777

3.813

1.589

26.058

0.318

70.087

14.268

0.064

0.858

13.155

0.191

28.322

VGA3/60 Hz

640 x 480

31.469

31.778

3.813

1.589

26.058

0.318

59.940

16.683

0.064

0.794

15.761

0.064

25.175

640/72 Hz

640 x 480

37.861

26.413

1.270

3.810

20.825

0.508

72.809

13.735

0.079

0.528

13.100

0.026

31.500

640/75 Hz

640 x 480

37.500

26.667

2.032

3.810

20.317

0.508

75.000

13.333

0.080

0.427

12.800

0.027

31.500

800/56 Hz

800 x 600

35.156

28.444

2.000

3.556

22.222

0.667

56.250

17.778

0.057

0.626

17.067

0.028

36.000

800/60 Hz

800 x 600

37.879

26.400

3.200

2.200

20.000

1.000

60.317

16.579

0.106

0.607

15.840

0.026

40.000

A : Line time total B : Horizontal sync width O : Frame time total P : Vertical sync width

C : Back porch D : Active time Q : Back porch R : Active time

E : Front porch S : Front porch

Polarity H.Sync

V.Sync

Remark

Video

Sync

C D

Positive

Negative

Separate

Separate Sync

Positive

Video

Q R S

Sync

Negative

Separate

Negative

Separate

Negative

Separate

Positive

Negative

Separate

Positive

Separate

GH15LS/GH15ES/GH15MS 2-3

2 Product Specifications

QRS

Video

Sync

Horizontal

Vertical

CDE

Video

Sync

Table 2-1. Timing Chart (Continued)

Timing

fH (kHz)

A µsec

B µsec

C µsec

D µsec

E µsec

fV (Hz)

O msec

P msec

Q msec

R msec

S msec

Clock Frequency (MHz)

Mode

800/72 Hz

800 x 600

48.077

20.800

2.400

1.280

16.000

1.120

72.188

13.853

0.125

0.478

12.480

0.770

50.000

800/75 Hz

800 x 600

46.875

21.333

1.616

3.232

16.162

0.323

75.000

13.333

0.064

0.448

12.800

0.021

49.500

VESA

1024/60Hz

1024x768

48.363

20.677

2.092

2.462

15.754

0.369

60.004

16.666

0.124

0.600

15.880

0.062

65.000

1024/70Hz

1024x768

56.476

17.707

1.813

1.920

13.653

0.320

70.069

14.272

0.106

0.513

13.599

0.053

75.000

1024/75Hz

1024x768

60.023

16.660

1.219

2.235

13.003

0.203

75.029

13.328

0.050

0.466

12.795

0.017

78.750

640/67 Hz

640 x 480

35.000

28.571

2.116

3.175

21.164

2.116

66.667

15.000

0.086

1.114

13.714

0.086

30.240

MAC.

832/75 Hz

832 x 624

49.726

20.110

1.117

3.910

14.524

0.559

74.551

13.414

0.060

0.784

12.549

0.020

57.284

A : Line time total B : Horizontal sync width O : Frame time total P : Vertical sync width

C : Back porch D : Active time Q : Back porch R : Active time

E : Front porch S : Front porch

Polarity H.Sync

V.Sync

Remark

Video

Sync

C D

Positive

Separate

Separate Sync

Positive

Video

Q R S

Sync

Negative

Separate

Negative

Separate

Positive

Separate

Negative

Separate

Negative

Separate

2-4 GH15LS/GH15ES/GH15MS

3-1-1 Removing the Stand

1. Remove 4 screws in the hinge area.

2. Disconnect Power Cord and Signal Cable.

3. Pry it off the back of the monitor.

3-1-2 Main Body Disassembly

1. Remove 2 screws on the two corner of the Rear Cover.

2. Remove Rear Cover from the Front Cover.

3. Remove 4 screws on the Shield and remove the shield.

4. Disconnect Inverter wire, Function PCB wire and Interface wire. Remove 3 screws on the Main PCB and remove 2 screws on the D sub shield.

5. Remove 3 screws on the power PCB and remove 2 screws on the Inverter PCB.

6. Remove the Main PCB Assembly.

7. Remove 3 screws on the Function PCB from locking area of Function knob and remove Function PCB.

3-1-3 Standard Stand Disassembly

1. Remove 2 screws from the Stand front.

2. Remove 7 screws from the Stand Bottom.

3. Remove Stand Rear from the Stand assembly.

4. Remove 5 screws from the Stand assembly.

5. Remove the Neck front from the Stand assembly.

6. Remove 2 screws from the Stand assembly.

7. Remove Neck Rear from the Stand assembly.

8. Remove 4 screws from the Stand assembly.

GH15LS/GH15ES/GH15MS 3-1

3 Disassembly and Reassembly

This section of the service manual describes the disassembly and reassembly procedures for the GH15LS/GH15ES/GH15MS monitor.

WARNING: This monitor contains electrostatically sensitive devices. Use with 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 Disassembly and Reassembly

3-2 GH15LS/GH15ES/GH15MS

1. After confirm there is nothing

on the disk

Turn the LCD module over

and put it on a flat desk set to

the ground.

3-2 Replacement Order of Lamp Assemblies (GH15LS/GH15ES/GH15MS : Samsung Panel)

2. Push down the stopper and slide the lamp unit.

3. Please take out the lamp

unit from the LCD module.

3 Disassembly and Reassembly

GH15LS/GH15ES/GH15MS 3-3

4. Please fix the new lamp

units on the LCD module :

opposite process 2 and 3

* Replacement of lamp unit should be done at the power off state and recommanded clean

bench condition.

3-3 Reassembly

Reassembly procedures are in the reverse order of Disassembly procedures.

Memo

3 Disassembly and Reassembly

3-4 GH15LS/GH15ES/GH15MS

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