SAMSUNG DP14LT7N Service Manual

COLOR MONITOR

DP14LS DP14LT DP15LS DP15LT

Manual

SERVICE

COLOR MONITOR CONTENTS

1. Precautions

2. Product Specifications

3. Operating Instructions

4. Disassembly & Reassembly

5. Alignment & Adjustments

6. Troubleshooting

7. Exploded View & Parts List

8. Electrical Parts List

9. Block Diagram

10. Wiring Diagram

11 Schematic Diagrams

Samsung Electronics Co., Ltd. April 1999 Printed in Korea Code No.: BH68-00128A

WARNINGS

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

2. Disconnect the AC power before servicing.

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

1-1-1 Servicing the High Voltage VR

and CRT :

WARNING:Damaged IC202 may cause excessive

x-ray emissions.

1. When servicing the high voltage system, remove the static charge by connecting a 10 kohm resistor in series with an insulated wire (such as a test probe) between the chassis and the anode lead.

2. If the HV VR requires adjustment: This monitor does not need to adjust high voltage, high voltage step is saved at IC202, adjusting this high voltage to 24.5±0.5 kV - 14Ó, 25.0±0.5 kV - 15Ó.

3. When troubleshooting a monitor with excessively HV, avoid being unnecessarily close to the monitor. Do not operate the monitor for longer than is necessary to locate the cause of excessive voltage.

4. High voltage should always be kept at the rated value, no higher. Only when high voltage is excessive are X-rays capable of penetrating the shell of the CRT, including the lead in glass material. Operation at high voltages may also cause failure of the CRT or high voltage circuitry.

5. When the HV regulator is operating properly, there is no possibility of an X-ray problem. Make sure the HV does not exceed its specified value and that it is regulating correctly.

6. The CRT is especially designed to prohibit X-ray emissions. To ensure continued X-ray protection, replace the CRT only with one that is the same or equivalent type as the original.

7. Handle the CRT only when wearing shatterproof goggles and after completely discharging the high voltage anode.

8. Do not lift the CRT by the neck.

1-1-2 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 line cord directly into a 120V AC outlet. With the unitÕs 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.

Figure 1-1. Leakage Current Test Circuit

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.

Components identified by on schematics and parts lists must be sealed by a soldering iron after replacement and adjustment.

DP14L*/DP15L* 1-1

1 Precautions

1-1 Safety 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

1. Servicing precautions are printed on the cabinet, and should be followed closely.

2. Always unplug the unitÕs AC power cord from the AC power source before attempting to: (a) remove or reinstall any component or assembly, (b) disconnect PCB plugs or connectors, (c) connect all test components in parallel with an electrolytic capacitor.

3. 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.

4. 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 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 Òanti-staticÓ can generate electrical charges sufficient to damage ESDs.

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

6. 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.

7. Never defeat any of the +B voltage interlocks. Do not apply AC power to the unit (or any of its assemblies) unless all solid-state heat sinks are correctly installed.

8. Always connect a test instrumentÕs ground lead to the instrument chassis ground before connecting the positive lead; always remove the instrumentÕs 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.

9. Indicates ESDs on the Schematic Diagram in this manual.

1 Precautions

1-2 DP14L*/DP15L*

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.

1-2 Servicing Precautions

WARNING1: First read the “Safety Precautions” section of this manual. If unforeseen circumstances

create conflict between the servicing precautions and safety precautions, always follow the safety precautions.

WARNING2: An electrolytic capacitor installed with the wrong polarity might explode.

DP14L*/DP15L* 2-1

2 Product Specifications

2-1 Specifications

Picture Tube: 14-Inch (36 cm); 13.2-Inch (33.5 cm) viewable, 90° Deflection,

15-Inch (38 cm); 13.8-Inch (35 cm) viewable, flat-face tube, 90° Deflection,

0.28 mm Dot pitch, Semi-tint, Non-glare, Antistatic silica coating, Invar shadow mask

Scanning Frequency Horizontal: 30 kHz to 55 kHz (Automatic) - 14” / 30 kHz to 61 kHz (Automatic) - 15”

Vertical: 50 Hz to 120 Hz (Automatic)

Display Colors Unlimited colors

Maximum Resolution Horizontal : 1024 Dots

Vertical : 768 Lines

Input Video Signal Analog, 0.7 Vp-p positive at 75 Ω, internally terminated

Input Sync Signal Separate Sync : TTL level positive/negative

Maximum Pixel Clock 14” : 65 MHz, 15” : 80 MHz

Active Display 14” 15”

Horizontal 255 mm ± 4 mm (4:3 ratio) 267 mm ± 4 mm (4:3 ratio) Vertical 191 mm ± 4 mm 200 mm ± 4 mm

Input Voltage AC 90 to 264 Volts, 60 Hz/50 Hz ± 3 Hz

Power Consumption 75 Watt (Max.)

Dimensions 14” 15”

Unit (W x D x H) 13.70 x 14.65 x 14.49 Inches (348 x 372 x 368 mm) 14.25 x 15.12 x 15.12 Inches (362 x 384 x 384 mm) Carton (W x D x H) 16.61 x 18.11 x 15.35 Inches (422 x 460 x 390 mm) 17.87 x 19.57 x 17.52 Inches (454 x 497 x 445 mm)

Weight (Net/Gross) 14” : 23.4 lbs (10.6 kg) / 26.9 lbs (12.2 kg)

15” : 26.5 lbs (12.0 kg) / 31.5 lbs (14.3 kg)

Environmental Considerations Operating Temperature : 32°F to 104°F (0°C to 40°C)

Humidity : 10 % to 80 %

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

Humidity : 5 % to 95 %

• This above Models complies with SWEDAC (MPR II) recommendations for reduced electromagnetic fields.

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

Item Description

2 Product Specifications

2-2 DP14L*/DP15L*

2-2 Pin Assignments

Sync Type

Pin No.

15-Pin Signal Cable Connector (Figure 2-1)

Separate

Red

Green

Blue

GND

DDC Return

GND-R

GND-G

GND-B

Reserved

GND-Sync/Self-raster

GND

DDC Data

H-Sync

V-Sync

DDC Clock

Figure 2-1. Male Type

2 Product Specifications

DP14L*/DP15L* 2-3

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)

Polarity H.Sync

V.Sync

Remark

IBM VESA

800/85 Hz 800 x 600

1024/60 Hz 1024 x 768

(14”)

1024/75 Hz 1024 x 768

(15”)

640/60 Hz 640 x 480

720/70 Hz 720 x 400

31.469

31.777

3.813

1.907

25.422

0.636

70.087

14.268

0.064

1.080

12.711

0.413

28.322

Negative

Positive

Separate

31.469

31.778

3.813

1.907

25.422

0.636

59.940

16.683

0.064

1.048

15.253

0.318

25.175

Negative

Separate

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

Negative

Separate

43.269

23.111

1.556

2.222

17.778

1.556

85.008

11.764

0.069

0.578

11.093

0.023

36.000

Negative

Separate

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

Positive

Separate

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

Positive

Separate

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

Negative

Separate

60.023

16.660

13.003

3.658

13.206

3.454

75.029

13.328

12.795

0.533

12.812

0.516

78.750

Positive

Separate

800/75 Hz 800 x 600

640/75 Hz 640 x 480

640/85 Hz 640 x 480

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.

QRS

Video

Sync

Horizontal

Vertical

CDE

Video

Sync

Separate Sync

Table 2-1. Timing Chart

Mode

Timing

C D

Video

Sync

Video

Q R S

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

VIDEO

Horizontal

Vertical

H/V Composite Sync

Memo

2 Product Specifications

2-4 DP14L*/DP15L*

DP14L*/DP15L* 3-1

Location Symbol Description

1 Power Button

Power Indicator LED

Adjustment Buttons

Side Pincushion Button

Horizontal Position Button

Trapezoid Button

Brightness Control

Contrast Control

Parallelogram

V-Linearity

Pinbalance Button

Degauss

Recall

User Delete

Tilt (Option: 15”)

V-Moire

Vertical Size Button

Vertical Position Button

Horizontal Size Button

14 17

45186 7 8 9 10 11

Table 3-1. Front Panel Controls

Figure 3-1. Front Control Panel

3 Operating Instructions

3-1 Front View and Control

Memo

3 Operating Instructions

3-2 DP14L*/DP15L*

DP14L*/DP15L* 3-1

Location Symbol Description

1 Power Button

Power Indicator LED

Adjustment Buttons

Side Pincushion Button

Horizontal Position Button

Trapezoid Button

Brightness Control

Contrast Control

Parallelogram

V-Linearity

Pinbalance Button

Degauss

Recall

User Delete

Tilt (Option: 15”)

V-Moire

Vertical Size Button

Vertical Position Button

Horizontal Size Button

14 17

45186 7 8 9 10 11

Table 3-1. Front Panel Controls

Figure 3-1. Front Control Panel

3 Operating Instructions

3-1 Front View and Control

Memo

3 Operating Instructions

3-2 DP14L*/DP15L*

4-1-1 Cabinet Disassembly

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

2. Remove the Stand from the monitor. (Refer to Stand manual)

3. Incline the monitor by lifting the rear of the monitor.

4. Push the Opening jig each groove along the top of the monitor till it makes a ÒttakÓ sound. (2 grooves : Left and Right, Make sure each snap is disengaged.)

5. Squeeze the hold-snap on bottom of the monitor using your hand.

6. Insert the Opening jig into the groove then release the hold-snap.

DP14L*/DP15L* 4-1

4 Disassembly and Reassembly

This section of the service manual describes the disassembly and reassembly procedures for the DP14L*/DP15L* monitors.

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

these components.

4-1 Disassembly

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

2. To remove the Rear Cover, you must use the special opening jig tool.

Figure 1

Figure 2

Figure 3

Figure 4

7. When the hold-snap release, lift the Rear Cover slightly to make sure it doesnÕt reengage while you release the snap on the other side.

8. In a similar manner, Release the hold-snap on the opposite side.

9. Pull the Rear Cover up off the monitor.

10. Using pinch-nose pliers or ling-nose pliers, acrefully disconnect the Anode Cap from the CRT.

Warning: Do not touch the Anode contact

on the CRT (High Voltage may remain).

Note : If the hold-snap on the bottom of the

Front Cover is broken, secure the cabinet by applying a 4x16 screw in the extra holes on each side of the cabinet.

4-1-2 Removing the CRT Socket PCB

1. Complete all previous steps.

2. Disconnect the CRT and Main PCB ground wires between the CRT Socket PCB and Shield Cover. (DP14LS only)

3. Lift up the Video Spring and remove the CRT Socket PCB from the CRT.

4. Disconnect all connectors on the CRT Socket PCB.

5. Using a solder iron, disconnect Ground (G2) on the back of the Video Shield and remove the Shield Cap.

6. Remove the screw on the front of the Shield Socket.

7. Desolder the 4 tabs on the CRT Socket PCB and remove Shield.

8. Place the Video PCB on a flat, level surface that is protected from static electricity.

4 Disassembly and Reassembly

4-2 DP14L*/DP15L*

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

4-1-3 Removing the Main PCB

1. Complete all previous steps.

2. Disconnect the Degaussing Coil at GT601 and GT602 on the Main PCB.

3. Disconnect all easily accessible ground wires on the Main PCB and Bottom Chassis.

4. Disconnect the DY connector at the CN303 connector on the Main .

5. Using the jig, release the snaps (2) connecting the Front Cover and Main PCB then lift up the Bottom to separate the two Shield.

6. Remove the screws on the back and along each side of the Bottom Chassis.

7. Carefully lift the Main PCB AssÕy and remove the remaining ground wires.

8. Place the Main PCB AssÕy on a flat, level surface that is protected from static electricity.

4-1-4 CRT Ass’y Disassembly

1. Complete all previous steps.

2. Straighten the Degaussing Coil Assembly coated metal ties and lift the Coil AssÕy from the CRT.

3. Remove the four corner screws and lift the CRT up and away from the Front Cover Assembly and place it on a padded surface.

Caution: Do not lift the CRT by the neck.

If you will be returning this CRT to the monitor, be sure to place the CRT face downward on a protective pad.

4 Disassembly and Reassembly

DP14L*/DP15L* 4-3

Figure 10

4-2 Reassembly

Reassembly procedures are in the reverse order of Disassembly procedures.

Memo

4 Disassembly and Reassembly

4-4 DP14L*/DP15L*

5-1-1 Before Making Adjustments

5-1-1 (a) ORIENTATION

When servicing, always face the monitor to the east.

5-1-1 (b) MAGNETIC FIELDS

Whenever possible, use magnetic field isolation equipment such as a Helmholtz field to surround the monitor. If a Helmholtz field is not available, frequently degauss the unit under test.

Caution: Other electrical equipment may cause

external magnetic fields which may interfere with monitor performance.

Use an external degaussing coil to limit magnetic build up on the monitor. If an external degaussing coil is not available, use the internal degaussing circuit. However, do not use the internal degaussing circuit more than once per 30 minutes.

5-1-1 (c) WARM-UP TIME

The monitor must be on for 30 minutes before starting alignment procedures. Warm-up time is especially critical in Color Temperature and White Balance adjustments.

5-1-1 (d) SIGNAL

Analog, 0.7 Vp-p positive at 75 ohm, internal termination Sync: Separate (TTL level negative/positive)

5-1-1 (e) SCANNING FREQUENCY

Horizontal: 30 kHz to 55 kHz (automatic) 14Ó

30 kHz to 61 kHz (automatic) 15Ó

Vertical: 50 Hz to 120 Hz (automatic) Unless otherwise specified, adjust at the 800 x 600

mode (H : 53.7 kHz, V: 85 Hz) -14Ó/15Ó signals. Refer to Table on page 2-3.

5-1-1 (f) +B 13 V LINE CHECK

No beam Contrast: Maximum Brightness: Maximum

Check the DC 13 V ± 0.2 V at Cathode of D616 Point and GND.

5-1-1 (g) HIGH VOLTAGE CHECK

No beam Contrast: Maximum Brightness: Maximum

Check the high voltage to 24.5 ± 0.5 kV - 14Ó,

25 ± 0.5 kV - 15Ó at anode and GND.

5-1-1 (h) CENTER RASTER

Adjust VR501 so that the back raster comes to the center when you apply a signal of 60 kHz/75 Hz - 15Ó .

5-1-1 (i) BRIGHTNESS AND CONTRAST

Unless otherwise specified, adjust brightness and contrast buttons:

Brightness: Maximum

(press Å button until the LED is blink)

Contrast: Maximum

(press Å button until the LED is blink)

5-1-2 Required Equipment

The following equipment may be necessary for adjustment procedures:

5-1-2 (a) DISPLAY CONTROL ADJUSTMENT

1. Non-metallic (Ð) screwdriver: 1.5 mm Non-metallic (Ð) screwdriver: 3 mm

2. Philips (+) screwdriver: 1.5 mm

3. Non-metallic hexkey: 2.5 mm

4. Digital Multimeter (DMM), or Digital Voltmeter (DVM)

DP14L*/DP15L* 5-1

5 Alignment and Adjustments

This section of the service manual explains how to make permanent adjustments to the monitor. Directions are given for adjustments using the monitor Interface Board Ver. 2.0 and software (Softjig).

5-1 Adjustment Conditions

Caution: Changes made without the SoftJig are saved only to the user mode settings. As such, the

settings are not permanently stored and may be inadvertently deleted by the user.

5. Signal generator, or Computer with a video board that uses the ET-4000 chipset (strongly recommended if using Samsung DM 200 software) and that displays: 800 x 600 @ 85 Hz, or 800 x 600 @ 75 Hz (minimum).

6. Personal computer

7. Required software: Softjig.exe from Samsung, Samsung DM200, or DisplayMate for Windows from Sonera Technologies

8. Interface Board Ver. 2.0 Code No. BH81-90001K

9. Parallel communications cable (25-pin to 25-pin); Code No. BH81-90001H

10. Signal cable (15-pin to 15-pin cable with additional 3-pin connector); Code No. BH81-90001J

11. 5 V DC adapter, not supplied

Note: SoftJig Assembly (includes items 8, 9 and 10

Code No. BH81-90001L

5-1-2 (b) COLOR ADJUSTMENTS

1. All equipment listed in 5-1-2 (a), above

2. Color analyzer, or any luminance measurement equipment

5-1-3 Connecting the SoftJig

Connect the monitor to the signal generator and/ or PC as illustrated in Figures 5-1 and 5-2.

Note: The signal cable connector which includes

the 3-wire cable must connect to the monitor. If you use Setup 2 (PC only, no signal generator) you can only make adjustments to the signal timing available on that computer system. To make corrections to all factory timings requires the use of an additional signal generator.

5-1-4 After Making Adjustments

After finishing all adjustments, test the monitor in all directions. If, for example, the monitor does not meet adjustment specifications when facing north, reposition the monitor to face east and readjust. This time, try for an adjustment closer to the ideal setting within the tolerance range. Test the unit again in all directions. If the monitor again fails to meet specifications in every direction, contact your Regional After Service Center for possible CRT replacement.

5 Alignment and Adjustments

5-2 DP14L*/DP15L*

MONITOR

INTERFACE BOARD VER. 2.0

SIGNAL GENERATOR

7 PIN MINI DIN CONNECTOR

SIGNAL CABLE

5V DC ADAPTOR

PARALLEL CABLE

Figure 5-1. Setup 1, With Signal Generator

MONITOR

INTERFACE BOARD VER. 2.0

7 PIN MINI DIN CONNECTOR

SIGNAL CABLE

PARALLEL CABLE

D-SUB CONNECTOR

5V DC ADAPTOR

Figure 5-2. Setup 2, Without Signal Generator

5-2-1 Centering

Centering means to position the center point of the display in the middle of the display area. Horizontal size and position and vertical size and position control the centering of the display.

Adjust the horizontal size and vertical size to their optimal settings: 267 mm (H) x 200 mm (V) for 15Ó, 255 mm (H) x 191 mm (V) for 14Ó

Adjust the horizontal position and vertical position to within 4.0 mm of the center point of the screen.

l A - B l ² 5.0 mm. l C - D l ² 5.0 mm.

5-2-1 (a) HORIZONTAL MINIMUM SIZE ADJUSTMENT

CONDITIONS

Scanning frequency: 53.7 kHz/85 Hz Display image: Crosshatch pattern Brightness: Maximum Contrast: Maximum

PROCEDURE

Horizontal minimum size can be adjusted as follows using Softjig.

1. Display the timing 800 x 600/85 Hz.

2. Adjust horizontal size to minimum size using H_SIZE.

3. Adjust horizontal minimum size to 250 mm (15Ó) or 242 mm (14Ó) using H_SIZE MIN.

4. Adjust horizontal size to 267 mm (15Ó) or 255 mm (14Ó) using H_SIZE.

5. Press the ALL MODE SAVE horizontal minimum size for each timing is saved automatically.

If horizontal minimum size range cannot meet the spec, horiontal maximum size of 640 x 480/75 Hz including 800 x 600/60 Hz, 56 Hz, may be saturated or cannot overscan the bezel.

5-2-1 (b) VERTICAL SIZE ADJUSTMENT

CONDITIONS

Scanning frequency: 53.7 kHz/85 Hz Display image: Crosshatch pattern Brightness: Maximum Contrast: Maximum

Adjust the vertical size of the display pattern to 200 mm (15Ó) and 191 mm (14Ó). (Tolerance: ± 3 mm.)

5-2-1 (c) HORIZONTAL POSITION ADJUSTMENT

CONDITIONS

Scanning frequency: 53.7 kHz/85 Hz Display image: Crosshatch pattern

PROCEDURE

Center the test pattern on the raster.

5-2-1 (d) VERTICAL POSITION ADJUSTMENT

CONDITIONS

Scanning frequency: 53.7 kHz/85 Hz Display image: Crosshatch pattern

Center the test pattern on the raster.

5-2-2 Linearity

Linearity affects the symmetry of images as they appear on the screen. Unless each row or column of blocks in a crosshatch pattern is of equal size, or within the tolerances shown in Tables 5-1 and 5-2, an image appears distorted, elongated or squashed.

The formular of linearity (%)

Table 5-1. Standard Modes Linearity: 800 x 600/85Hz

Table 5-2. Other Modes Linearity: VGA, SVGA, XGA,

MAC, etc.

5 Alignment and Adjustments

DP14L*/DP15L* 5-3

5-2 Display Control Adjustments

DISPLAY AREA

EDGE OF BEZEL

Figure 5-3. Centering

Supported Timing Mode

Each block (14 %)

Difference between

adjacent blocks (5 %)

Standard Timing Modes

Each block (10 %)

Difference between

adjacent blocks (4 %)

2 x (Max – Min)

= x 100

Max + Min

5-2-3 Trapezoid Adjustment

CONDITIONS

Scanning frequency: 53.7 kHz/85 Hz Display image: Crosshatch pattern

Make the the test pattern rectangular.

Figure 5-4. Trapezoid

5-2-4 Parallelogram Adjustment

CONDITIONS

Scanning frequency: 53.7 kHz/85 Hz (14Ó/15Ó) Display image: Crosshatch pattern

To activate the Parallelogram Adjustment function, push both the Horizontal Position and Vertical Position buttons and hold them in for longer than 3 seconds, or until the power indicator LED changes from green to blink and back to green.

Use the Increase (+) and Decrease (Ð) buttons to correct the display shape.

Figure 5-5. Parallelogram

5-2-5 Side Pincushion Adjustment

CONDITIONS

Scanning frequency: 53.7 kHz/85 Hz (14Ó/15Ó) Display image: Crosshatch pattern

After pushing the Side Pincushion button once, push the Increase (+) and Decrease (Ð) buttons to straighten the sides of the test pattern.

5-2-6 CRT Tilt Adjustment ( Option)

TILT ADJUSTMENT (DP15L* With Tilt)

Push the V-Posi and H-Size simultaneously until Led blinks and back on again. Push the Increase (+) and Decrease (Ð) buttons to correct the Tilt.

5-2-7 Vertical Linearity Adjustment

To activate the vertical linearity adjustment, push both the horizontal position and horizontal size buttons and hold then in for longer than 3 seconds, or until the power indicator LED changes from green to blink and back to green.

Use the Increase (+) and Decrease (Ð) buttons to correct the display shape.

5-2-8 Pin Balance Adjustments

To activate the pin balacne function, push both the horizontal position and vertical Size buttons and hold then in for longer than 3 seconds, or until the power indicator LED changes from green to blink and back to green.

Use the Increase (+) and Decrease (Ð) buttons to correct the display shape.

5-2-9 Degauss

Push the contrast and brightness buttons simultaneously. The degaussing circuit can effectively function only once per 30 minutes. If available, use an external degaussing coil during servicing.

5-2-10 Delete User Mode Data

To delete the picture data from the user modes, push the contrast button and side pincushion button for 5 or more seconds simultaneously.

5-2-11 Recall

To delete the picture data from current user mode, push the contrast button and trapzoid button for 5 or more seconds simultaneoulsy.

5 Alignment and Adjustments

5-4 DP14L*/DP15L*

2.2 mm 2.2 mm

| C1 |, | C2 | ≤ 2.0 mm, | D1 |, | D2 | ≤ 2.2 mm.

Figure 5-6. Pincushion

FRONT BEZEL

BACK RASTER

Figure 5-7. CRT Tilt Adjustment

2.2 mm 2.2 mm

2.2 mm

Before making adjustments, check that the video signals are as follows:

Video : Analog, 0.7 Vp-p (at 75 ½ termination) Sync : Separate TTL level

Unless otherwise specified, use 800 x 600 mode signal (53.7 kHz/85 Hz) for adjustments.

5-3-1 Color Coordinates (Temperature)

Color temperature is a measurement of the radiant energy transmitted by a color. For computer monitors, the color temperature refers to the radiant energy transmitted by white. Color coordinates are the X and Y coordinates on the chromaticity diagram of wavelengths for the visible spectrum.

CONDITIONS

Measurement instrument: Color analyzer Scanning frequency: 53.7 kHz/85 Hz Display image: White flat field at

center of display area

Luminance: Maximum

PROCEDURE

Using the directions in sections 5-3-2 through 5-3-5, adjust the Color Coordinates for 9300K to x = 0.283 ± 0.02 and y = 0.298 ± 0.02

5-3-2 Back Raster Color Adjustment

CONDITIONS

Measurement instrument: Color analyzer Scanning frequency: 53.7 kHz/85 Hz Display image: Back raster pattern Brightness: Maximum Contrast: Maximum

PROCEDURE

1. Adjust the Screen VR on the FBT so that the brightness of the Back Raster is 0.3 to 0.5 ft-L (typically 0.4 ft-L).

2. Adjust the G_CUT to center.

3. Adjust the B_CUT to set the ÒyÓ coordinate to

0.298 ± 0.02.

4. Adjust the R_CUT to set the ÒxÓ coordinate to

0.283 ± 0.02.

Note: If the above adjustments cannot be done to

each coordinate, adjust G_CUT to increase or decrease the green cutoff and repeat procedures 3 and 4.

5-3-3 Video Gain Adjustment

Figure 5-8. Green Box Pattern

CONDITIONS

Measurement instrument: Color analyzer Scanning frequency: 53.7 kHz/85 Hz Display image: Green box pattern

within range for which the ABL circuit is not active (1/3 to 1/2H and

1/3 to 1/2V). Brightness: Maximum Contrast: Maximum

PROCEDURE

1. Adjust G-Gain so that the brightness of the

green gain is 40 ± 1 ft-L (typically 40 ft-L).

5-3-4 White Balance Adjustment

Figure 5-9. Full White Pattern

CONDITIONS

Measurement instrument: Color analyzer Scanning frequency: 53.7 kHz/85 Hz Display image: Full white pattern Brightness: Maximum Contrast: Maximum

PROCEDURE

1. Display the full white pattern.

2. Adjust R-Gain and B-Gain so that the video is

white. (x = 0.283 ± 0.02 and y = 0.298 ± 0.02)

5 Alignment and Adjustments

DP14L*/DP15L* 5-5

5-3 Color Adjustments

1/3H-1/2H

1/3V-1/2V

FRONT BEZEL OPENING

BACK RASTER

GREEN WINDOW

FRONT BEZEL OPENING

BACK RASTER

WHITE WINDOW

5-3-5 White Balance Fine Adjustment

CONDITIONS

Measurement instrument: Color analyzer Scanning frequency: 53.7 kHz/85 Hz Display image: Full white pattern X-Y coordinates: x = 0.283 ± 0.02

y = 0.298 ± 0.02

PROCEDURE

1. Adjust the Contrast control so that the brightness of the video is about 5 ft-L.

2. Check whether the white coordinates of the video meet the specification above. If they do not, adjust them so that they do.

3. Adjust the Contrast to maximum luminance.

4. Check whether the white coordinates still meet the specification above. If they do not, adjust them so that they do.

5-3-6 ABL Point Adjustment

CONDITIONS

Measurement instrument: Color analyzer Scanning frequency: 53.7 kHz/85 Hz Display image: Full white pattern Brightness: Maximum Contrast: Maximum

PROCEDURE

Adjust ABL so that the brightness level is 35 ± 1 ft-L.

5-3-7 Focus Adjustment

CONDITIONS

Measurement instrument: Color analyzer Scanning frequency: 53.7 kHz/85 Hz Display image: ÒHÓ character pattern Brightness: Maximum Contrast: Maximum

PROCEDURE

1. Adjust the Focus VR on the FBT to display the sharpest image possible.

2. Use Locktite to seal the Focus VR in position.

5-3-8 Luminance Uniformity Check

CONDITIONS

Measurement instrument: Color analyzer Scanning frequency: 53.7 kHz/85 Hz Display image: White flat field Brightness: Cut off point at 30 ft-L

PROCEDURE

Measure luminance at nine points on the display screen: top left corner, top center, top right corner, center row left side, center, center row right side, bottom left corner, bottom center, and bottom right corner.

5-3-9 Color Purity Adjustment

Color purity is the absence of undesired color. Conspicuous mislanding (unexpected color in a uniform field) within the display area shall not be visible at a distance of 50 cm from the CRT surface.

CONDITIONS

Orientation: Monitor facing east Scanning frequency: 53.7 kHz/85 Hz Display image: White flat field Luminance: Cutoff point at the center

of the display area

Caution: Color purity adjustments should only

be attempted by qualified personnel.

PROCEDURE

For trained and experienced service technicians only.

Use the following procedure to correct minor color purity problems:

1. Make sure the display is not affected by external magnetic fields. Use an external degaussing coil to neutralize magnetic fields which may be affecting color purity.

2. Very carefully break the glue seal between the 2-pole purity convergence magnets (PCM), the band and the spacer .

3. Make sure the spacing between the PCM assembly and the CRT stem is

22.5 mm ± 1 mm.

4. Display a red pattern over the entire display area.

5. Adjust the Purity Magnet Rings on the PCM assembly to display a pure green pattern. (Optimal setting: x = x = 0.283 ± 0.02, y = 0.298 ± 0.02)

6. Repeat steps 4 and 5 using a red pattern and then again, using a blue pattern.

Table 5-3. Color Purity Tolerances

(For 9300K white color adjustment: x = 0.283 ± 0.02, y = 0.298 ± 0.02)

7. When you have the PCMs properly adjusted, carefully gule them together with Locktite to prevent their movement during shipping.

5 Alignment and Adjustments

5-6 DP14L*/DP15L*

Red: x = 0.625 ± 0.015 y = 0.340 ± 0.015

Green: x = 0.310 ± 0.015 y = 0.592 ± 0.015

Blue: x = 0.150 ± 0.015 y = 0.063 ± 0.015

DP14L*/DP15L* 6-1

6 Troubleshooting

6-1 General Troubleshooting

Notes: 1. If a picture does not appear, fully rotate the brightness and contrast controls clockwise and reinspect.

2. Check the following circuits.

• No raster appears: Power circuit, Horizontal output circuit, H/V control circuit, and H/V output circuit.

• High voltage develops but no raster appears: Video output circuits.

• High voltage does not develop: Horizontal output circuits.

6-1-1 No Picture

Check signal cable connection, H/V Sync input. Check Timing mode (14”: 30~55kHz, 15”: 30~61kHz). Check Cont,

Bright

key (all Max) and Screen VR (G2).

Check key components of secondary part. :

D406, D407, D408, D515, Q402, Q410, Q504, Rectifier

diodes (D608 ~ D612), IC101 (Vcc~GND)

Check key components of primary part. :

D601 ~ D607, FH601, IC601, TH602

Check SW601 (Power key)

Refer to 6-2-16 No Video.

Refer to 6-2-1 No Power.

Refer to 6-2-3 No Raster and 6-2-12 High Voltage Failure.

Refer to 6-2-17 Micom Failure.

Refer to 6-2-13 I2C Failure.

6 Troubleshooting

6-2 DP14L*/DP15L*

6-1-2 Shut Down

Check X-ray protection circuit. :

D502, D503, R510

Check key components of secondary part. :

D406, D407, D408, D515, IC101 (Vcc ~ GND)

Q402, Q504, Rectifier diodes

Check and replace IC601.

Refer to 6-2-1 No Power.

Refer to 6-2-3 No Raster and 6-2-12 High Voltage Failure.

Refer to 6-2-17 Micom Failure.

Refer to 6-2-13 I2C Failure.

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