Samsung pn15vt service manual

COLOR MONITOR

PN15VT / VO PN15HT / HO

Manual

SERVICE

COLOR MONITOR CONTENTS

1. Precautions

2. Product Specifications

3. Disassembly & Reassembly

4. Alignment & Adjustments

5. Troubleshooting

6. Exploded View & Parts List

7. Electrical Parts List

8. Block Diagram

9. Wiring Diagram

10. Schematic Diagrams

PN15VT/HT

PN15VO/HO

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 and CRT :

WARNING: A high voltage adjusted to the wrong

value 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. 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.

3. 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.

4. 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.

5. 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.

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

7. 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 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.

Figure 1-1. Leakage Current Test Circuit

1-1-3 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.

PN15VT/VO PN15HT/HO

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 unit’s 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 “anti-static” 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 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.

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

1 Precautions

1-2 PN15VT/VO

PN15HT/HO

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: A high voltage adjusted to the wrong value may cause excessive X-ray emissions. WARNING3: An electrolytic capacitor installed with the wrong polarity might explode.

PN15VT/VO PN15HT/HO

2-1

2 Product Specifications

2-1 Specifications

Picture Tube: 15-Inch (38 cm): 13.8-inch (35 cm) viewable,

Full-square flat-face tube, 90˚ Deflection, Semi- tint, Non-glare, Invar shadow mask, Anti-static silica coating, 0.28 mm Dot pitch

Scanning Frequency Horizontal 30 kHz ~ 55 kHz (Automatic) 30 kHz ~ 70 kHz (Automatic)

Vertical 50 Hz ~ 120 Hz (Automatic) 50 kHz ~ 160 kHz (Automatic) Display Colors Unlimited colors Maximum Resolution Horizontal 1024 Dots 1280 Dots

Vertical 768 Lines 1024 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 rate 65 MHz 110 MHz

Active Display Horizontal : 267 mm ± 4 mm, Vertical : 200 mm ± 4 mm Input Voltage AC 90 ~ 264 Volts, 60 Hz / 50 Hz ± 3 Hz Power Consumption 80 Watt (max.) 75 Watt (max.) Dimensions (W x D x H)

With Base 14.01 x 14.92 x 14.54 Inches (356 x 379 x 369.5 mm) Weight (Net/Gross) 11.5 kg (25.35 lbs) / Standard : 13.3 kg (29.32 lbs), Special : 13.4 kg (29.54 lbs) Environmental Considerations Operating Temperature : 32°F ~ 104°F (0°C ~ 40°C)

Humidity : 10 % ~ 80 % Storage Temperature : –4°F ~ 113°F (–20°C ~ 45°C) Humidity : 5 % ~ 95 %

• Above models comply with SWEDAC (MPR II) recommendations for reduced electromagnetic fields.

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

Item

Description

PN15VT/VO

PV15HT/HO

2 Product Specifications

2-2 PN15VT/VO

PN15HT/HO

2-2 Pin Assignments

Figure 2-1. Male Type Figure 2-2. Male Type

Sync Type

Pin No.

Macintosh

Separate

1 2 3 4 5 6 7 8

9 10 11 12 13 14 15

Red Green Blue N-C GND (DDC Return) GND-R GND-G GND-B N-C GND-Sync./Self-Test N-C DDC Data H-Sync. V-Sync. DDC Clock

GND-R Red H/V Sync. Sense 0 Green GND-G Sense 1 Reserved Blue Sense 2 GND V-Sync. GND-B GND H-Sync.

2 Product Specifications

PN15VT/VO PN15HT/HO

2-3

QRS

Video

Sync

Horizontal

Vertical

CDE

Video

Sync

Separate 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.

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

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

1024/75 Hz 1024 x 768

1024/85 Hz 1024 x 768

VGA3/60 Hz

640 x 480

VGA2/70 Hz

720 x 400

31.469

31.778

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 Negative Separate

43.269

23.111

1.556

2.222

17.778

1.556

85.008

11.764

0.671

0.578

11.093

0.023

36.000

Negative Negative 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 Positive

Separate

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

Positive Positive

Separate

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

Positive Positive

Separate

640/85 Hz 640 x 480

Table 2-1. Timing Chart

Mode

Timing

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

Positive Positive

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 Negative Separate

640/75 Hz 640 x 480

(PN15VT/VO)

(PN15HT/HO)

1024/60 Hz 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

65.000

Negative Negative Separate

2 Product Specifications

2-4 PN15VT/VO

PN15HT/HO

Memo

3-1-1 Before making Disassembly

1. Disconnect the power cord from the monitor.

2. With a pad beneath it, stand the monitor on its front with the screen facing downward and the base close to you.

3-1-2 Cabinet Disassembly

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

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

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

4. Remove 2 screws on the Rear cover.

5. Pull the Rear Cover up off the monitor.

6. Remove the Shield.(TCO 99)

6. 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).

PN15VT/VO PN15HT/HO

3-1

3 Disassembly and Reassembly

This section of the service manual describes the disassembly and reassembly procedures for the PN15VT/VO/HT/HO monitors.

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

Figure 1

Figure 2

Figure 3

3-1-3 Removing the CRT Socket PCB

1. Complete all previous steps.

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

3. Disconnect all connectors on the CRT Socket PCB.

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

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

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

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

3-1-4 Removing the Main PCB

1. Complete all previous steps.

2. Disconnect the Degaussing Coil at CN603 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 CN401 connector on the Main .

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

6. Disconnect the Tilt connector at the CN304 connector on the Main PCB.(PN15HT/HO)

7. Disconnect the Sub PCB connector at the CN203 connector on the Main PCB.

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

9. Carefully lift the Main PCB Ass’y and remove the remaining ground wires.

10. Place the Main PCB Ass’y on a flat, level surface that is protected from static electricity.

3-1-5 CRT Ass’y Disassembly

1. Complete all previous steps.

2. Straighten the Degaussing Coil Assembly coated metal ties and lift the Coil Ass’y 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.

3 Disassembly and Reassembly

3-2 PN15VT/VO

PN15HT/HO

Figure 5

Figure 4

3-2 Reassembly

Reassembly procedures are in the reverse order of Disassembly procedures.

4-1-1 Before Making Adjustments

4-1-1 (a) ORIENTATION

When servicing, always face the monitor to the east.

4-1-1 (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.

4-1-1 (c) WARM-UP TIME

The monitor must be on for 30 minutes before starting alignment. Warm-up time is especially critical in color temperature and white balance adjustments.

4-1-1 (d) SIGNAL

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

4-1-1 (e) SCANNING FREQUENCY

Horizontal: 30 kHz ~ 55 kHz (Automatic) : VT/VO

30 kHz ~ 70 kHz (Automatic) : HT/HO

Vertical: 50 Hz ~ 120 Hz (Automatic) : VT/VO

50 Hz ~ 160 Hz (Automatic) : HT/HO

Unless otherwise specified, adjust at the 800 x 600 mode (54 kHz/85 Hz) : VT/VO, 1024 x 768 mode (68 kHz/85 Hz) : HT/HO signal.

4-1-2 Required Equipment

The following equipment may be necessary for adjustment procedures:

4-1-2 (a) DISPLAY CONTROL ADJUSTMENT

1. Non-metallic (–) screwdriver:

1.5, 2.5, 3 mm

2. Non-metallic (+) screwdriver:

1.5, 2.5, 3 mm

3. Digital Multimeter (DMM), or Digital Voltmeter

4. Signal generator, or DM200 software

5. Software: Softjig or DM200

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

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

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

9. 5 V DC adapter, not supplied

10. Personal computer

Note: Softjig Ass’y (includes items 6, 7 and 9)

Code No. BH81-90001L

4-1-2 (b) COLOR ADJUSTMENTS

1. All equipment listed in 4-1-2 (a), above

2. Color analyzer, or any luminance measurement equipment

PN15VT/VO PN15HT/HO

4-1

4 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).

4-1 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.

4-1-3 Connecting the SoftJig

Connect the monitor to the signal generator and/ or PC as illustrated in Figures 4-1 and 4-2.

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.

4 Alignment and Adjustments

4-2 PN15VT/VO

PN15HT/HO

MONITOR

INTERFACE BOARD VER. 2.0

SIGNAL GENERATOR

3-WIRE CABLE

SIGNAL CABLE

5V DC ADAPTOR

PARALLEL CABLE

Figure 4-1. Setup 1, With Signal Generator

MONITOR

INTERFACE BOARD VER. 2.0

3-WIRE CABLE

SIGNAL CABLE

PARALLEL CABLE

D-SUB CONNECTOR

5V DC ADAPTOR

Figure 4-2. Setup 2, Without Signal Generator

4-2-1

HIGH VOLTAGE ADJUSTMENT (Only HT/HO)

Signal: 800 x 600 (54 kHz/85 Hz) Display image: Full White Pattern Contrast: Maximum Brightness: Maximum Limit: 25.0 kV ± 0.2 kV

Measure the hight voltage level at the anode cap. High voltage should be within the limit as above. If the high voltage needs adjustment use the following procedure.

PROCEDURE

1. Turn the power off and disconnect the AC line cord from the power source.

2. Turn the power on after connecting high voltage Probe.

3. Using the jig, adjust the high voltage to the specification.

* High Voltage Adjustment PROCEDURE using Softjig

① Select matching model name in “Model” field. ➁ Select “ @7: Zero Beam” in menu after

selecting “Extra 1”

➂ Adjust high voltage using control bar after

selecting “HV MIN”

➃ Turn the power off/on after adjustment

finished.

➄ Check the high voltage has been fixed with

adjusted value after reselecting “@7: Zero Beam”.

4-2-2 CENTER RASTER

Adjust VR401 so that the back raster comes to the center when you apply each basic mode.

4-2-3 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.

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

|A – B| ≤ 4.0 mm. |C – D| ≤ 4.0 mm.

Figure 4-3. Centering

4-2-3 (a-1) HORIZONTAL SIZE ADJUSTMENT CONDITIONS

Scanning frequency: 54 kHz/85 Hz (VT/VO)

68 kHz/85 Hz (HT/HO) Display image: Crosshatch pattern Brightness: Maximum Contrast: Maximum

Use control bar after selecting “SIZE B+” in left menu to adjust the horizontal size of the display pattern to 255 mm . (Tolerance: ± 1 mm.)

4-2-3 (a-2) HORIZONTAL SIZE ADJUSTMENT

Use control bar after selecting “H-SIZE” in left menu to adjust the horizontal size of the display pattern to 267 mm . (Tolerance: ± 3 mm.)

4-2-3 (b) VERTICAL SIZE ADJUSTMENT CONDITIONS

Scanning frequency: 54 kHz/85 Hz Display image: Crosshatch pattern Brightness: Maximum Contrast: Maximum

Use control bar after selecting “V-SIZE” in left menu to adjust the vertical size of the display pattern to 200 mm. (Tolerance: ± 3 mm.)

4 Alignment and Adjustments

PN15VT/VO PN15HT/HO

4-3

4-2 Display Control Adjustments

DISPLAY AREA

EDGE OF BEZEL

4-2-3 (c) HORIZONTAL POSITION ADJUSTMENT CONDITIONS

Scanning frequency: 54 kHz/85 Hz Display image: Crosshatch pattern

Use control bar after selecting “H-POSITION” in left menu to center the horizontal image on the raster.

4-2-3 (d) VERTICAL POSITION ADJUSTMENT CONDITIONS

Scanning frequency: 54 kHz/85 Hz Display image: Crosshatch pattern

Use control bar after selecting “V-POSITION” in left menu to center the vertical image on the raster.

4-2-4 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 Table 4-1 an image appears distorted, elongated or squashed.

Horizontal Linearity = 2x x100

Vertical Linearity = 2x x100

Table 4-1

❈ Preset Mode : 54KHz / 85Hz

Pre-load Mode : Refer to Timing Chart

4-2-4 (a) HORIZONTAL LINEARITY ADJUSTMENT CONDITIONS

Scanning frequency: 54 kHz/85 Hz Display image: Crosshatch pattern Brightness: Maximum Contrast: Maximum

To adjust the Horizontal Linearity, refer to Table 4-1 for the tolerance range.

Increase or decrease H_LIN to optimize the image.

4-2-4 (b) VERTICAL LINEARITY ADJUSTMENT CONDITIONS

Scanning frequency: 54 kHz/85 Hz Display image: Crosshatch pattern Brightness: Maximum Contrast: Maximum

To adjust the Vertical Linearity, refer to Table 4-1 for the tolerance range.

Use control bar after selecting “V-LINEARITY BAL” in left menu to optimize the image.

4-2-5 Trapezoid Adjustment

CONDITIONS

Scanning frequency: 54 kHz/85 Hz Display image: Crosshatch pattern Brightness: Maximum Contrast: Maximum

Use control bar after selecting “TRAPEZOID” in left menu to make the image area rectangular.

Figure 4-4. Trapezoid

4-2-6 Pinbalance Adjustment

CONDITIONS

Scanning frequency: 54 kHz/85 Hz Display image: Crosshatch pattern Brightness: Maximum Contrast: Maximum

Use control bar after selecting “PINBALANCE” in left menu to optimize the image.

4 Alignment and Adjustments

4-4 PN15VT/VO

PN15HT/HO

| A – B | < 4 mm

D1 D2 D1

Figure 4-5. Pinbalance

| D1 |, | D2 | ≤ 2.0 mm

Preset mode

≤ 4% ≤ 10%

Adjacent Linearity

Entire Linearity

Pre-load mode (48kHz~) ≤ 5% ≤ 14%

X max-X min

X max+X min Y max-Y min Y max+Y min

4-2-7 Parallelogram Adjustment

CONDITIONS

Scanning Frequency: 54 kHz/85 Hz Display image: Crosshatch pattern Brightness: Maximum Contrast: Maximum

Use control bar after selecting “PARALLEL” in left menu to make the image area rectangular.

Figure 4-6. Parallelogram

4-2-8 Side Pincushion Adjustment

CONDITIONS

Scanning frequency: 54 kHz/85 Hz Display image: Crosshatch pattern

Use control bar after selecting “PINCUSHION” in left menu to straighten the sides of the image area.

4-2-9 Tilt Adjustment (Only HT/HO)

CONDITIONS

Scanning Frequency: 54 kHz/85 Hz Display image: Crosshatch pattern Brightness: Maximum Contrast: Maximum

Use control bar after selecting “ROTATION” in left menu to correct the tilt of the display.

4-2-10 Degauss

No adjustments are available for the degaussing circuit. The degaussing circuit can effectively function only once per 30 minutes.

4-2-11 To Delete the User Mode Data

To delete the adjustment data from the user modes, click “@4: USER DELETE” in right ment.

4-2-12 Save the Data

To save the adjustment data for a mode, press “@3: ALL MODE SAVE” in right ment.

4 Alignment and Adjustments

PN15VT/VO PN15HT/HO

4-5

4 mm

Figure 4-7. Pincushion

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

CAUTION : Check below condition before color

adjustment Video signal : Analog 0.7 Vp-p (at 75 Ω) Sync : TTL level (H, V seperate signal)

* Select “Color” in Softjig menu for color adjustment.

4-3-1 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: 54 kHz/85 Hz Display image: White flat field at

center of display area

Luminance: Maximum

PROCEDURE

Use the directions in sections 4-3-2 through 4-3-3 to adjust the color coordinates for: 9300K to x = 0.283 ± 0.015, y = 0.298 ± 0.015 6500K to x = 0.313 ± 0.015, y = 0.329 ± 0.015

4-3-2 Color Adjustments for 9300K

4-3-2 (a) BACK RASTER COLOR ADJUSTMENT CONDITIONS

Scanning frequency: 54 kHz/85 Hz Display image: Back raster pattern Brightness: Maximum Contrast: Maximum

1. Select “@1: CHANNEL 1” in right menu to

control the color for 9300K.

2. Adjust the luminance of the back raster to between 0.5 to 0.7 ft-L using contron bar after selecting “GREEN CUTOFF” in the menu.

3. Use control bar after selecting “BLUE CUTOFF” in left menu to set the “y” coordinate to 0.298 ± 0.015

4. Use control bar after selecting “RED CUTOFF” in left menu to 0.283 ± 0.015

* If color values would not be matched desirable

values, repeat sequence 3 and 4 after readjusting “GREEN CUTOFF” control a little different.

4-3-2 (b) WHITE BALANCE ADJUSTMENT CONDITIONS

Scanning frequency: 54 kHz/85 Hz Display image: White box pattern Brightness: 0.06ft-L at Back Raster

Pattern Display

Contrast: Maximum

1. Use control bar after selecting “RED GAIN”, “GREEN GAIN” and “BLUE GAIN” to adjust the luminance to 50 ft-L with the color coordinates ranged for 9300K to x = 0.283 ± 0.015, y = 0.298 ± 0.015.

Figure 4-8. White Box Pattern

4-3-2 (c) ABL ADJUSTMENT CONDITIONS

Scanning frequency: 54 kHz/85 Hz Display image: Full white pattern Brightness: Maximum Contrast: Maximum

Figure 4-9. Full White Pattern

1. Check the ABL. If it is not within the

specifications, use the ABL controls to adjust it. (38 ± 1 ft-L )

2. Select “@4: COLOR SAVE” to save the data.

3. Select “@6: ALL COLOR SAVE” to save the

CH2.

4-3-2 (d) WHITE BALANCE ADJUSTMENT VERIFICATION CONDITIONS

Scanning frequency: 54 kHz/85 Hz

1/3H-1/2H

1/3V-1/2V

FRONT BEZEL OPENING BACK RASTER

WHITE WINDOW

FRONT BEZEL OPENING BACK RASTER

WHITE WINDOW

4 Alignment and Adjustments

4-6 PN15VT/VO

PN15HT/HO

4-3 Color Adjustments

Display image: Back raster pattern

Full White Pattern

X-Y Coordinates: x = 0.283 ± 0.015,

y = 0.298 ± 0.015 ABL Luminance Refer to 4-3-2(c) Brightness: Maximum Contrast: 5 ft-L, 24 ft-L

1. Check whether the color coordinates of the

back raster satisfy the above spec. If they do not, return to 4-3-2 (a) and readjust

all settings.

2. Display a full white pattern.

3. Select “Geometry” in softjig menu.

4. Select “@7: 5-ft “ in right menu.

5. Check whether the white coordinates of the

video meet the above coordinates spec.

6. Select “@8: 24-ft “ in right menu.

7. Check whether the white coordinates of the

video satisfies the above spec. If they do not, return to 4-3-2 (a) and readjust

all settings. Select “Color” and click “@2: CHANNEL 2”

for color ajdustment for 6500K Repeat the sequence of 9300K adjustment. The luminance values the same as 9300K, but the color coordinated of back raster and white box are : x = 0.313 ± 0.015 y = 0.329 ± 0.015

4-3-3 Luminance Uniformity Check

Luminance is considered uniform only if the ratio of lowest to highest brightness areas on the screen is not less than 7.5:10.

CONDITIONS

Scanning frequency: 54 kHz/85 Hz

(1024 x 768) Display image: White flat field Brightness: Cut off point at 24 ft-L Contrast: Maximum

PROCEDURE

Measure luminance at nine points on the display screen (see figure below).

4-3-4 Focus Adjustment

CONDITIONS

Scanning frequency: 54 kHz/85 Hz

(1024 x 768) Display image: “H” character pattern Brightness: Cut off point 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.

4-3-5 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: 54 kHz/85 Hz Display image: White flat field Luminance: Cut off point at the center

of the display area Note: 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.

2. Make sure the spacing between the PCM

assembly and the CRT stem is 29 mm ± 1 mm.

3. Display a green pattern over the entire display

area.

4. Adjust the purity magnet rings on the PCM

assembly to display a pure green pattern. (Optimum setting: x = 0.295 ± 0.015, y = 0.594 ± 0.015)

Table 4-2. Color Purity Tolerances

(For 9300K color adjustment: x = 0.283 ± 0.015, y = 0.298 ± 0.015)

5. When you have the PCMs properly adjusted,

carefully glue them together to prevent their movement during shipping.

4 Alignment and Adjustments

PN15VT/VO PN15HT/HO

4-7

Figure 4-10. Luminance Uniformity Check Locations

Red: x = 0.640 ± 0.015 y = 0.323 ± 0.015 Green: x = 0.295 ± 0.015 y = 0.594 ± 0.015 Blue: x = 0.142 ± 0.015 y = 0.066 ± 0.015

Memo

4 Alignment and Adjustments

4-8 PN15VT/VO

PN15HT/HO

PN15VT/VO PN15HT/HO

5-1

5 Troubleshooting

5-1 Parts Level Troubleshooting

Notes: Check the following circuits.

• No raster appears: Power circuit, Horizontal output circuit.

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

• High voltage does not develop: Horizontal output circuits.

5-1-1 No Power Supply

Chirping noise exists?

Check and replace IC601.

Check and replace D601 and FH1

Done.

Yes

Repeating start?

Check and replace D606.

Yes

IC601 Pin 1 waveform is right?

Check and replace D614, IC601,

Q602 and ZD601.

Yes

C622 Voltage is 13 V ± 0.5V?

Check and replace IC201, IC301,

IC401, Q402, Q404,

IC603, Q609,and Q611.

Yes

Operate normally?

Replace Main board.

Yes

Verify voltages.

WAVEFORMS

100 V (IC601, #1)

CH1 P-P = 100 V CH1 RMS = 350.2 V

5 Troubleshooting

5-2 PN15VT/VO

PN15HT/HO

5-1-2 DPMS Failure

Make No H/V Sync.

(power off mode)

Check signal source

H/V Sync. video level.

LED blinks?

Check IC201 Pin 40.

Yes

+12 V line off?

Check IC201 Pin 6.

Yes

IC601 Pin 1 output

voltage exists?

Refer to 5-1-1 No Power Supply.

Done

Yes

WAVEFORMS

100V (IC601, #1)

CH1 P-P = 100V CH1 RMS = 325.8 V

5 Troubleshooting

PN15VT/VO PN15HT/HO

5-3

5-1-3 H_Deflection Failure

Does Horizontal pluse signal

appear at at Pin 26 of IC401?

Check IC401.

Yes

Does 20 Vp-p signal appear

at Collector of Q418?

Check Q418.

Check Q402, Q404 and T401.

WAVEFORMS

5.00 V (IC401, #28)

1.00V (IC401, #26)

5.00 V (Q418, Collector)

Does PWM output signal appear

at Pin 28 (B_out) of IC401?

Check IC401.

Check 12 V line.

Yes

Does DC 12V appear at

Pin 29 of IC401?

Yes

7-1-4 S Correction Failure

S1~S3 signals are right at each

frequency block?

Check S1 ~ S3 signal.

Check and replace Q404, Q410, Q411,

(Q409, Q414 : HT/HO)

Q415, and Q416.

Yes

Check and replace IC201.

5 Troubleshooting

5-4 PN15VT/VO

PN15HT/HO

5-1-5 H_Lin. Failure

IC201 Pin 21 voltage varies with

different H_Lin. DAC values?

IC603 Pin 14 voltage varies with

different H_Lin. DAC values?

Check +13 V_1, Coil_5 V line.

Check some parts around IC603.

Check Q412, Q413 and T402.

Yes

Replace IC201.

5-1-6 Invariable H_Size

IC401 Pin 28 voltage varies with

different B_OUT DAC values?

Q402 Gate output duty varies with

different B_OUT DAC values?

Check some parts around Q402,

IC401 Pin 4 ~ 6.

Yes

Check and replace IC401.

5-1-7 Abnormal H_Size

IC401 Pin 24 output duty

varies with different B+ offset

DAC values?

Q408 Collector waveform is

right?

Check and replace Q405,

Q406, Q407, and Q408.

Check some parts

around D409 and L401.

Yes

Check and replace IC201.

WAVEFORMS

5.00 V (Q408, Collector)

5 Troubleshooting

PN15VT/VO PN15HT/HO

5-5

5-1-8 Side Pin or Trap Failure

IC401 Pin 24 output exists?

Yes

Check and replace IC401.

Refer to 5-1-7

Abnormal H_Size

5-1-9 Para. or Pin Balance Failure

IC401 Pin 24 output varies with

different DAC values?

Replace IC401.

WAVEFORMS

1.00 V (IC401, #24)

5-1-10 Tilt Failure (only HT/HO)

IC201 Pin 20 output duty varies

with different DAC values?

IC603 Pin 3 output varies with

different DAC values?

Check and replace IC603.

Check and replace Q301 and Q302.

Yes

Check and replace IC201.

Check tilt connector connection

Refer to 5-1-7

Abnormal H_Size

Yes

5 Troubleshooting

5-6 PN15VT/VO

PN15HT/HO

5-1-11 V Deflection Failure

13V and –10V lines are on?

IC401 Pin 23 output exists?

Check and replace IC401.

Yes

Refer to 5-1-1 No Power Supply

IC301 Pin 6 output exists?

Check and replace some parts

around IC301.

Yes

Check DY connector connection.

WAVEFORMS

1.00 V (IC401, #12)

10.0 V (IC301, #6)

5-1-12 V Size or Position Variation Failure

IC401 Pin 23 output varies with

different DAC values?

Yes

Check and replace IC201 and IC401.

Check and replace IC301.

5 Troubleshooting

PN15VT/VO PN15HT/HO

5-7

5-1-13 High Voltage Failure

IC401 Pin 28 OSC pulse exists?

Q402 Gate driving pulse exists?

Check and replace Q401.

Yes

Check and replace IC401

and +12 V line.

Q402 Drain pulse exists?

Check and replace Q403 and L402.

Yes

Done

WAVEFORMS

5.00 V (Q402, Gate)

CH1 P-P = 2.00 V CH1 RMS = 7.692V

5.00 V (IC401, #28)

CH1 P-P = 2.00 V CH1 RMS = 5.868 V

50.0 V (Q402, Drain)

CH1 P-P = 50.0 V CH1 RMS = 73.7V

IC101 Pin 22 input exists and

varies with different patterns?

Check and replace IC101.

Input full white pattern to monitor.

Yes

T501 Pin 8 output exists?

Check and replace T501.

Yes

IC201 Pin 26 output exists and varies with different patterns?

Check and replace IC201.

Yes

Done

Check CN102.

5-1-14 ABL Failure

5 Troubleshooting

5-8 PN15VT/VO

PN15HT/HO

5-1-15 Dynamic Focus Failure

T502 Pin 6 output is right?

Yes

Replace the C432.

T502 Pin 1 input is right?

Check and replace T502.

Yes

Check the connection between FBT

Focus pin and CRT Socket PCB.

WAVEFORMS

50.0 V (T502, #6)

CH1 P-P = 50.0 V CH1 RMS = 75.6 V

100 V (T502, #1)

CH1 P-P = 100V CH1 RMS = 124.0 V

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