Samsung GH17LS User Manual

TFT-LCD MONITOR

GH17LS GH17ES

SERVICE

Manual

TFT-LCD MONITOR CONTENTS

1. Precautions

2. Product Specifications

3. Disassembly & Reassembly

4. Alignments & Adjustments

5. Troubleshooting

6. Exploded View & Parts List

7. Electrical Parts List

8. Block Diagram

9. Wiring Diagram

10. Schematic Diagrams

11. Panel Description

Samsung Electronics Co.,Ltd.

416, Maetan-3Dong, Paldal-Gu, Suwon City, Kyungki-Do, Korea. Printed in Korea P/N : BN68-00225C-00 http://www.samsungmonitor.com (SyncMaster Worldwide) http://www.samsung-monitor.com (SyncMaster USA) http://www.sec.co.kr/monitor (Korea)

Trademarks

This manual may not, in whole or in part, be copied, photocopied, reproduced, translated, or converted to any electronic or machine readable form without prior written permission of Samsung Electronics Co., Ltd.

GH17LS/GH17ES Service Manual

First edition July 2001.

Printed in Korea.

ii GH17LS/GH17ES

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

GH17LS/GH17ES and MacMaster Cable Adapter are trademarks of Samsung Electronics Co., Ltd.

Macintosh, Centris, Quadra, Duo Douk, and Power Macintosh are trademarks of Apple Computer, Inc.

All other trademarks are the property of their respective owners.

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.

GH17LS/GH17ES 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 GH17LS/GH17ES

2 Product Specifications

2-1 Specifications

Description

Item

LCD Panel TFT-LCD panel, RGB vertical stripe, normally black transmissive,

17-Inch viewable, 0.264 (H) x 0.264 (V) mm pixel pitch

Scanning Frequency Horizontal : 30 kHz ~ 81 kHz (Automatic)

Vertical : 56 Hz ~ 85 Hz (~XGA), 76 Hz (SXGA); GH17ES

Display Colors 16,7 Million colors

Maximum Resolution Horizontal : 1280 Pixels

Vertical : 1024 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

Level : TTL level (V high ≥ 2.0 V, V low ≤ 0.8 V), Sync-on-Green (≤ –0.25 V)

Maximum Pixel Clock rate 135 MHz

GH17LS

Vertical : 56 Hz ~ 76 Hz; GH17LS

GH17ES

Active Display Horizontal/Vertical 338 ± 3 mm/270 ± 3 mm

AC power voltage & Frequency AC 90 ~ 264 Volts, 60/50 Hz ± 3 Hz

Power Consumption 42 W (max), 40W (normal)

Dimensions Unit (W x D x H) 17.5 x 18.0 x 8.2 Inches (444 x 457 x 208.4 mm) Carton (W x D x H) 20.7 x 10.7 x 20.9 Inches (527 x 271 x 532 mm)

Weight (Net/Gross)

Environmental Considerations Operating Temperature : 50°F ~ 104°F (10°C ~ 35°C)

• GH17LS/GH17ES comply with SWEDAC (MPRII) recommendations for reduced electromagnetic fields.

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

5.4 kg (11.9 lbs) / 7.9 kg (17.4 lbs)

Humidity : 10 % ~ 80 % Storage Temperature : -68°F ~ 113°F (-20°C ~ 45°C) Humidity : 5 % ~ 95 %

5.8 kg (12.8 lbs) / 8.3 kg (18.3 lbs)

GH17LS/GH17ES 2-1

2 Product Specifications

2-2 Pin Assignments

Pin No.

10 11 12 13 14 15

Sync Type

Separate Composite

1 2 3 4 5 6 7 8 9

Red Green Blue GND DDC Return (GND) GND-R GND-G GND-B DDC Power Input (+5V) Self Raster GND Bi-Dr Data (SDA) H-Sync. V-Sync. DDC Clock (SCL)

15-Pin D-Sub Signal Cable Connector

Red Green Blue GND DDC Return (GND) GND-R GND-G GND-B DDC Power Input (+5V) Self Raster GND Bi-Dr Data (SDA) H/V-Sync. Not Used DDC Clock (SCL)

Sync-on-green

Red Green + H/V Sync. Blue GND DDC Return (GND) GND-R GND-G GND-B DDC Power Input (+5V) Self Raster GND Bi-Dr Data (SDA) Not Used Not Used DDC Clock (SCL)

2-2 GH17LS/GH17ES

2 Product Specifications

QRS

Video

Sync

Horizontal

Vertical

CDE

Video

Sync

VIDEO

Horizontal

Vertical

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

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 Freq. (MHz)

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

IBM

640 x 480

VGA3/

60 Hz

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

640/75 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

640/85 Hz

640 x 480

43.269

23.111

1.556

2.222

17.778

1.556

85.008

11.764

0.671

0.578

11.093

0.023

49.500

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

800/85 Hz

800 x 600

53.674

18.631

1.138

2.702

14.222

0.569

85.061

11.756

0.056

0.503

11.179

0.019

56.250

VESA

1024/60Hz

1024 x 768

48.363

20.677

2.092

2.462

15.754

0.369

60.004

16.666

0.124

0.600

15.880

0.062

75.000

1024/75Hz

1024 x 768

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

1024/85Hz

1024x768

68.677

14.561

1.016

2.201

10.836

0.508

84.997

11.765

0.044

0.524

11.183

0.015

94.500

1280/76Hz

1280x1024

(Analog Only) (Analog Only)

81.129

16.640

6.400

2.880

1280/75Hz

1280x1024

79.976

12.504

1.067

1.837

9.481

3.200

76.106

10.660

0.080

3.200

0.119

75.025

13.329

0.038

0.475

12.804

0.020

135.000

0.013

135.000

Polarity H.Sync

V.Sync

Remark

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

GH17LS/GH17ES 2-3

Sync

Negative

Positive

Separate

Video

C D

Negative

Separate

Separate Sync

Negative

Separate

Negative

Separate

Video

Q R S

Positive

Separate

Positive

Separate

Negative

Separate

Positive

Separate

Positive

Separate

H/V Composite Sync

Negative

Com.

Positive

Separate

Sync-on-Green

Sync

Green

Horizontal

Vertical

2 Product Specifications

Memo

2-4 GH17LS/GH17ES

3 Disassembly and Reassembly

This section of the service manual describes the disassembly and reassembly procedures for the GH17LS/GH17ES TFT-LCD monitors.

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.

3-1-1 Removing the Stand

1. With a pad beneath it, stand the monitor on its front with the screen facing downward and the base close to you. Make sure nothing will damage the screen.

2. Remove the 4 screws on the Stand.

Caution: Be careful. The signal cable and

power cable are still attached to the monitor.

3. Disconnect the Signal Cable and Power Cord.

3-1-2 Main Body Disassembly

1. Remove 2 screws on the Rear Cover.

2. Pull the Rear Cover up and off the monitor.

3. Remove 7 screws on the PCB Shield.

4. Disconnect the Function PCB wire (10P) between the Function PCB and the CN103 connector on the Main PCB.

5. Disconnect 4 Inverter wires between the Panel and the CN2, 3, 4, 5 connectors on the Inverter PCB.

6. Disconnect the interface wire (30P) between the Panel and the CN102 connector on the Main PCB.

7. Remove 3 screws on the Main PCB and 2 screws on the Inverter PCB and 2 screws on the Power Adapter PCB.

8. Disconnect the 12P harness between CN1 connector on the inverter and CN104 connector on the Main PCB.

9. Carefully lift the Main PCB Assembly and Inverter PCB and place them on a flat, level surface that is protected from static electricity.

10. Remove 4 screws on the Bracket Guide. (GH17LS only)

11. Remove 3 screws on the Function PCB from the Front Cover and remove the Function PCB and Function Knob.

GH17LS/GH17ES 3-1

3 Disassembly and Reassembly

3-2 Reassembly

Reassembly procedures are in the reverse order of Disassembly procedures.

3-2 GH17LS/GH17ES

4 Alignments and Adjustments

Serial cable

Function

Board

Power

cable

RS232

JIG

Power

AdapterADBoard

This section of the service manual explains how to use the RS232 JIG. This function is needed when AD Board Change and program memory (IC110) change.

4-1 Required Equipment

The following equipment is necessary for adjusting the monitor:

• Computer with Windows 95 , Windows 98 , or Windows NT .

R R

• RS232 JIG.

4-2 RS232 Jig Setup

1. Install Hyper Terminal program from

windows system.

2. Configure Baud rate to 19200, select

appropriate COM port.

3. Make the Hardware setup as per

figure shown.

4-3 Changing Board

Before replacing the AD Board, read all Panel information data by using RS232 JIG and hyper terminal.

1. Type character `B`.

Service Menu for Gogh 17 Model.

1. Read.

2. Modify upper Back Light Value.

3. Modify Lower back Light Value.

4. Modify Panel On Time Value.

5. Exit Service Menu

Enter 1

Upper Backlight Time Expired (in hours) : ***

Lower Backlight Time Expired (in hours) : ***

Panel On Time (in hours) : ***

Please note down these values. Than change to new board. Execute the command `B`, read the values. You will see these are set to default values. Change the values to the recorded values. Exit the service menu by `B` command.

Figure 4-1.

4. Establish the connection by selecting

“Connect” from hyper Terminal.

5. Power on the board, now you see messages in

the application window. If no messages than check for 1, 2 and 3 again.

Message :

2. Color Auto Adjustment

After function `1`. Assemble the monitor. And display 16-Gray pattern or black and white mixed pattern. Then push “Exit”, “-” and “+” key of function same time. During normal execution of Auto Algorithm the screen image may changed.

4-4 Program memory (IC110) change

Follow same method as changing Board (4-3).

GH17LS/GH17ES

4-1

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