Samsung HNC5527WX/XAA, ST54T8PCX/XAX Schematic

PROJECTION TV RECEIVER

Chassis : P55A(N) REV.1 Model: HCN5527WX/XAA

ST54T8PCX/XAX

PROJECTION TV RECEIVER CONTENTS

Precautions

Reference Information

Specifications

Alignment and Adjustments

Troubleshooting

Exploded View and Parts List

Electric Parts List

Block Diagrams

Wiring Diagram

Schematic Diagrams

10.

1. Precautions

1-1 Safety Precautions

1. Be sure that all of the built-in protective devices are replaced. Restore any missing protective shields.

2. When reinstalling the chassis and its assemblies, be sure to restore all protective devices, including: nonmetallic control knobs and compartment covers.

3. Make sure that there are no cabinet openings through which people—particularly children—might insert fingers and contact dangerous voltages. Such openings include the spacing between the picture tube and the cabinet mask, excessively wide cabinet

ventilation slots, and improperly fitted back

covers.

If the measured resistance is less than 1.0 megohm or greater than 5.2 megohms, an abnormality exists that must be corrected before the unit is returned to the customer.

4. Leakage Current Hot Check (Figure 1-1): Warning: Do not use an isolation transformer during this test. Use a leakagecurrent tester or a metering system that complies with American National Standards Institute (ANIS C101.1, Leakage Current for Appliances), and Underwriters Laboratories (UL Publication UL1410, 59.7).

5. With the unit completely reassembled, plug the AC line cord directly into the power 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: antennas, handle brackets, metal cabinets, screwheads and control shafts. The current measured should not exceed 0.5 milliamp. Reverse the powerplug prongs in the AC outlet and repeat the test.

Fig. 1-1 AC Leakage Test

6. Antenna Cold Check: With the unit’s AC plug disconnected from the AC source, connect an electrical jumper across the two AC prongs. Connect one lead of the ohmmeter to an AC prong. Connect the other lead to the coaxial connector.

7. X-ray Limits: The picture tube is especially designed to prohibit X-ray emissions. To ensure continued X-ray protection, replace the picture tube only with one that is the same type as the original. Carefully reinstall the picture tube shields and mounting hardware; these also provide X-ray protection.

8. High Voltage Limits: High voltage must be measured each time servicing is done on the B+, horizontal deflection or high voltage circuits. Correct operation of the X-ray protection circuits must be reconfirmed whenever they are serviced.

(X-ray protection circuits also may be called

“horizontal disable” or “hold-down”.)

Heed the high voltage limits. These include the X–ray Protection Specifications Label, and the Product Safety and X-ray Warning Note on the service data schematic.

Precautions

Samsung Electronics 1-1

LEAKAGE CURRENT

TESTER

DEVICE UNDER

TEST

TEST ALL

EXPOSED METAL

SURFACES

2-WIRE CORD

ALSO TEST WITH

PLUG REVERSED

(USING AC ADAPTER

PLUG AS REQUIRED)

EARTH

GROUND

(READING SHOULD

NOT BE ABOVE

0.5mA)

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

1-1 Safety Precautions (Continued)

9. High voltage is maintained within specified limits by close-tolerance, safety-related components and adjustments. If the high voltage exceeds the specified limits, check each of the special components.

10. Design Alteration Warning: Never alter or add to the mechanical or electrical design of this unit. Example: Do not add auxiliary audio or video connectors. Such alterations might create a safety hazard. Also, any design changes or additions will void the manufacturer’s warranty.

11. Hot Chassis Warning: Some TV receiver chassis are electrically connected directly to one conductor of the AC power cord. If an isolation transformer is not used, these units may be safely serviced only if the AC power plug is inserted so that the chassis is connected to the ground side of the AC source.

To confirm that the AC power plug is inserted correctly, do the following: Using an AC voltmeter, measure the voltage between the chassis and a known earth ground. If the reading is greater than 1.0V, remove the AC power plug, reverse its polarity and reinsert. Re-measure the voltage between the chassis and ground.

12. Some TV chassis are designed to operate with 85 volts AC between chassis and ground, regardless of the AC plug polarity. These units can be safely serviced only if an isolation transformer inserted between the receiver and the power source.

13. Some TV chassis have a secondary ground system in addition to the main chassis ground. This secondary ground system is not isolated from the AC power line. The two ground systems are electrically separated by insulating material that must not be defeated or altered.

14. Components, parts and wiring that appear to have overheated or that are otherwise damaged should be replaced with parts that meet the original specifications. Always determine the cause of damage or overheating, and correct any potential hazards.

15. Observe the original lead dress, especially near the following areas: Antenna wiring, sharp edges, and especially the AC and high voltage power supplies. Always inspect for pinched, out-of-place, or frayed wiring. Do not change the spacing between components and the printed circuit board. Check the AC power cord for damage. Make sure that leads and components do not touch thermally hot parts.

16. Picture Tube Implosion Warning: The picture tube in this receiver employs “integral implosion” protection. To ensure continued implosion protection, make sure that the replacement picture tube is the same as the original.

17. Do not remove, install or handle the picture tube without first putting on shatterproof goggles equipped with side shields. Never handle the picture tube by its neck. Some “in-line” picture tubes are equipped with a permanently attached deflection yoke; do not try to remove such “permanently attached” yokes from the picture tube.

18. Product Safety Notice: Some electrical and mechanical parts have special safety-related characteristics which might not be obvious from visual inspection. These safety features and the protection they give might be lost if the replacement component differs from the original—even if the replacement is rated for higher voltage, wattage, etc.

Components that are critical for safety are indicated in the circuit diagram by shading, ( ) or ( ).

Use replacement components that have the same ratings, especially for flame resistance and dielectric strength specifications. A replacement part that does not have the same safety characteristics as the original might create shock, fire or other hazards.

Precautions

1-2 Samsung Electronics

1-2 Servicing Precautions

1. Servicing precautions are printed on the cabinet. Follow them.

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 an electrical plug or connector, (c) Connect a test component 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 portion around the serviced part has not been damaged.

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 (500V) 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.

9. When some parts inside the optical engine (except lamp) are damaged, replace the whole optical engine.

Precautions

Samsung Electronics 1-3

Warning 1 : First read the “Safety Precautions” section of this manual. If some unforeseen circumstance creates a

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

Warning 2 : An electrolytic capacitor installed with the wrong polarity might explode.

“CAUTION : Double-pole/neutral fusing”

1-3 Precautions for Electrostatically Sensitive Devices (ESDs)

1. Some semiconductor (“solid state”) devices are easily damaged by static electricity. Such components are called Electrostatically Sensitive Devices (ESDs); examples include integrated circuits and some field-effect transistors. The following techniques will reduce the occurrence of component damage caused by static electricity.

2. Immediately before handling any semicon ductor components or assemblies, drain the electrostatic charge from your body by touching a known earth ground. Alternatively, wear a discharging wrist-strap device. (Be sure to remove it prior to applying power— this is an electric shock precaution.)

3. After removing an ESD-equipped assembly, place it on a conductive surface such as aluminum foil to prevent accumulation of electrostatic charge.

4. Do not use freon-propelled chemicals. These can generate electrical charges that damage ESDs.

5. Use only a grounded-tip soldering iron when soldering or unsoldering ESDs.

6. Use only an anti-static solder removal device. Many solder removal devices are not rated as “anti-static”; these can accumulate sufficient electrical charge to damage ESDs.

7. 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.

8. 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.

9. Minimize body motions when handling unpackaged replacement ESDs. Motions such as brushing clothes together, or lifting a foot from a carpeted floor can generate enough static electricity to damage an ESD.

Precautions

1-4 Samsung Electronics

CAUTION

These servicing instructions are for use by qualified service personnel only. To reduce the risk of electric shock do not perform any servicing other than that contained in the operating instructions unless you are qualified to do so.

Reference Information

Samsung Electronics 2-1

2. Reference Information

2-1 Tables of Abbreviations and Acronyms

A Ah Å dB dBm

°C °F °K F G GHz g H Hz h ips kWh kg kHz kΩ km km/h kV kVA kW I MHz

Ampere Ampere-hour Angstrom Decibel Decibel Referenced to One Milliwatt Degree Celsius Degree Fahrenheit degree Kelvin Farad Gauss Gigahertz Gram Henry Hertz Hour Inches Per Second Kilowatt-hour Kilogram Kilohertz Kilohm Kilometer Kilometer Per Hour Kilovolt Kilovolt-ampere Kilowatt Liter Megahertz

MV MW MΩ m µA µF µH µm µs µW mA mg mH mI mm ms mV nF

Ω

pF Ib rpm rps s V VA W Wh

Megavolt Megawatt Megohm Meter Microampere Microfarad Microhenry Micrometer Microsecond Microwatt Milliampere Milligram Millihenry Milliliter Millimeter Millisecond Millivolt Nanofarad Ohm Picofarad Pound Revolutions Per Minute Revolutions Per Second Second (Time) Volt Volt-ampere Watt Watt-hour

Table 2-1 Abbreviations

Reference Information

2-2 Samsung Electronics

Table 2-2 Table of Acronyms

ABL AC ACC AF AFC AFT AGC AM ANSI APC APC A/V AVC BAL BPF B-Y CATV CB CCD CCTV Ch CRT CW DC DVM EIA ESD ESD FBP FBT FF FM FS GND G-Y H HF HI-FI IC IC IF

Automatic Brightness Limiter Alternating Current Automatic Chroma Control Audio Frequency Automatic Frequency Control Automatic Fine Tuning Automatic Gain Control Amplitude Modulation American National Standards Institute Automatic Phase Control Automatic Picture Control Audio-Video Automatic Volume Control Balance Bandpass Filter Blue-Y Community Antenna Television (Cable TV) Citizens Band Charge Coupled Device Closed Circuit Television Channel Cathode Ray Tube Continuous Wave Direct Current Digital Volt Meter Electronics Industries Association Electrostatic Discharge Electrostatically Sensitive Device Feedback Pulse Flyback Transformer Flip-Flop Frequency Modulation Fail Safe Ground Green-Y High High-Frequency High Fidelity Inductance-Capacitance Integrated Circuit Intermediate Frequency

I/O L L LED LF MOSFET MTS NAB NEC NTSC OSD PCB PLL PWM QIF R RC RF R-Y SAP SAW SIF SMPS S/N SW TP TTL TV UHF UL UV VCD VCO VCXO VHF VIF VR VTR VTVM TR

Input/output Left Low Light Emitting Diode Low Frequency Metal-Oxide-Semiconductor-Field-Effect-Tr Multi-channel Television Sound National Association of Broadcasters National Electric Code National Television Systems Committee On Screen Display Printed Circuit Board Phase-Locked Loop Pulse Width Modulation Quadrature Intermediate Frequency Right Resistor & Capacitor Radio Frequency Red-Y Second Audio Program Surface Acoustic Wave(Filter) Sound Intermediate Frequency Switching Mode Power Supply Signal/Noise Switch Test Point Transistor Transistor Logic Television Ultra High Frequency Underwriters Laboratories Ultraviolet Variable-Capacitance Diode Voltage Controlled Oscillator Voltage Controlled Crystal Oscillator Very High Frequency Video Intermediate Frequency Variable Resistor Video Tape Recorder Vacuum Tube Voltmeter Transistor

Reference Information

Samsung Electronics 2-3

2-2 Description of Dynamic Focus

Most large-screen video display devices that are using CRT (including CDT) usually apply the Dynamic Focus (hereinafter D/F) circuit.

As CRT has non-spherical surface (perfect spherical surface = 1, non-spherical surface R>1), the distance that the electron beam emitted from the electron gun reaches to the center of CRT is different from the one that the electron beam reaches to the corners. (See Figure 1.) Only the beam, which has the equal distance as the beam from the electron gun to the center of CRT surface, can maintain the optimum focus. By this reason, focus dagradation at corners occurs inevitably. To recover this, the speed of the electron beam injected into the corners of CRT should increase and the focus dagradation by the difference of distances can be compensated. Increasing the voltage is used as a method of increasing the speed of the electron beam at the corners of screen. In this case, an ideal D/F voltage waveform is the form of parabola where the center of screen has low voltage and the corners has the highest voltages. The horizontal D/F waveform compensates the focus dagradation at left and right sides, but the vertical D/F waveform does at top and bottom sides. The horizontal D/F and vertical D/F waveforms are separately created and mix two signals to compensate the focus of the whole screen. And the vertical Dynamic Focus waveform is composed of the horizontal Dynamic Focus waveforms as much as the number of scanning lines. (See Figure 2.)

Fig. 1 Dynamic Focus Diagram (Horizantal)

Fig. 2 H/V Dynamic Focus Waveform

Reference Information

2-4 Samsung Electronics

2-3 IC Line Up

2-3-1 Progressive

Reference Information

Samsung Electronics 2-5

Reference Information

2-6 Samsung Electronics

2-4 MICOM IIC BUS LINE -UP

Specifications

Samsung Electronics 3-1

3. Specifications

Broadcasting System

Scanning System

Tuning Range

Antenna Impedance

Intermediate Frequency

Sound Output

Rated Voltage

W/B Coordinates

High Voltage

FUSE

Power Consumption

Dimension

Weight

NTSC

Progressive Scanning

VHF : CH2 ~ CH13

75 ohm Unbalanced

Video : 45.75 MHz

Sound : 42.25 MHz

Chrominance Subcarrier : 42.17 MHz

STD : 10W

MAX : 15W

120V / 60 Hz

Hx : 266 Hy : 280 Y : 8.9

Lx : 268 Ly : 283 Y : 0.38

29KV

250V/6.3A

CODE NO : 3601-000300

240W

1002 X 450 X 1070mm

39.4 X 17.7 X 42.1 inch

49Kg 108lbs

MEMO

3-2 Samsung Electronics

Alignment and Adjustments

Samsung Electronics 4-1

4. Alignment and Adjustments

4-1 When entering the service mode:

1. Turn on the TV, and then select “STANDARD”on the picture adjustment mode.

2. Turn off the TV (STAND-BY).

3. Enter the service mode by pressing the remote control keys in the following sequence :

Note : If necessary, re-do steps 1~3.

Initial display when the service mode is switched.

SERVICE / Sim-474A

DEFLECTION 480P OFFSET 1080i OFFSET CONVERGENCE OFFSET VIDEO ADJUST 1 VIDEO ADJUST 2 VIDEO ADJUST 3 VIDEO ADJUST 4 OPTION (E3h 98h 0ch) RESET / 02-05-03

1. When a RF signal is received

MAIN MENU MENU DISPLAY

CH UP/DOWN Select item by moving cursor

VOL UP/DOWN Decrease or increase the adjustment values

3. Service Mode Control Keys

< PRECAUTIONS >

1. When EEPROM IC (IC902) is replaced, first connect the power cord and wait for about 4~5 seconds.

2. After replacing EEPROM IC (IC902), enter the Service mode. Next, enter the standard data or the previous EEPROM IC data before replacement. And then check and adjust any items related to Geometric, Picture, Option.

Alignment and Adjustments

4-2 Samsung Electronics

4-2-1 Defection

4-2 Factory Data

☞ DVI connection item is corresponded to DVI application model.

ITEM INITIAL DATA

V Amp

V Shift

H EW

H Shift

V Linearity

Upper Linearity

Lower Linearity

VSC

H Parabola

Upper Corner

Lower Corner

H Trapezium

Bow

Range

0 ~ 63

6 fix

0 ~ 63

0 ~ 15

0 ~ 63

EEP-ROM Copy Data

480P

1080i

Remark

variable

fix

Angel

V Position

CXA Left Blk

CXA Right Blk

0 ~ 63

fix

Alignment and Adjustments

Samsung Electronics 4-3

4-2-2 480P Offset

ITEM INITIAL DATA

V Amp

V Shift

H EW

H Shift

V Linearity

Upper Linearity

Lower Linearity

VSC

H Parabola

Upper Corner

Lower Corner

H Trapezium

Bow

Range

-63 ~ 63

-15~ 15

-63 ~ 63

EEP-ROM Copy Data

RF 480P

1080i

Remark

variable

fix

Angel

V Position

CXA Left Blk

CXA Right Blk

-63 ~ 63

fix

Alignment and Adjustments

4-4 Samsung Electronics

4-2-3 1080i Offset

ITEM INITIAL DATA

V Amp 0

V Shift 0

H EW 0

H Shift 0

V Linearity 0

Upper Linearity 0

Lower Linearity 0

VSC 0

H Parabola 0

Upper Corner 0

Lower Corner 0

H Trapezium 0

Bow 0

Range

-63 ~ 63

-15~ 15

-63 ~ 63

EEP-ROM Copy Data

RF 480P

1080i

Remark

variable

fix

Angel 0

V Position 0

CXA Left Blk

CXA Right Blk

-63 ~ 63

Alignment and Adjustments

Samsung Electronics 4-5

4-2-4 CONVERGRNCE OFFSET

ITEM INITIAL DATA

Offset Enable

V Amp

V Shift

H EW

V Amp 1080i

V Shift 1080i

H EW 1080i

Range

0 variable

0 ~ 1

-63 ~ 63

EEP-ROM Copy Data

RF 480P

Remark

1080i

variable

Alignment and Adjustments

4-6 Samsung Electronics

4-2-5 VIDEO ADJUST 1

ITEM INITIAL DATA

R Cutoff 20

G Cutoff 20

B Cutoff 20

Color On/Off 1

CR offset 32 fix

CB offset 32

R Driver 31

G Driver 31

B Driver 31

Sub Bright 15

Sub Contrast 7

Sub Color 20

SubTint 7

Range

0 ~ 63

0 ~ 1

0 ~ 15

0 ~ 63

0 ~ 15

0 ~ 23

0 ~ 13

EEP-ROM Copy Data

RF-Copy

W/B

Control Value

8(AV/SV/DVD/480P)

1080i

Remark

variable

fix

variable

fix

variable

fix

CTI Level 1

CDL AXIS 2

LTI Level 0

0 ~ 3

1 (RF/AV/SV/DVD/480P/1080i)

1(RF/AV/SV/DVD/480P)

fix

Alignment and Adjustments

Samsung Electronics 4-7

4-2-6 VIDEO ADJUST 2

ITEM INITIAL DATA

ABL Mode 3

Gamma 2

DPIC Level 3

DC Trans 3

ABL TH 15

VM Level 2

VM Coring 0

VM f0 0

VM Limit 0

VM Delay 0

SHP CD 1

SHP f0 0

SHP f1 & P/O 11

Range

0 ~ 3

0 ~ 15

0 ~ 3

0 ~ 1

0 ~ 15

EEP-ROM Copy Data

RF 480P

2 (RF/AV/SV/DVD/480P)

0 (RF/AV/DVD)

1 (480P)

1 (AV/SV/DVD/Comp2)

13 1 (RF/AV/SVHS/DVD/Comp2)

1080i

Remark

fix

AKB Time 13

Y/C Delay 30

PIP Y/C Delay 30

BAND PASS F 1

HIGH PASS F 3

0 ~ 31

0 ~ 7

Alignment and Adjustments

4-8 Samsung Electronics

4-2-7 VIDEO ADJUST 3

ITEM INITIAL DATA

VSU 2

Melody Volume 4

H Comp 0

V Comp 0

Pin Comp 0

AFC Comp 0

Sync Comp 0

NR Off Value 5

V-Mute(x100ns)

Range

0 ~ 15

0 ~ 20

0 ~ 15

0 ~ 7

0 ~ 1

0 ~ 9

0 ~ 10

EEP-ROM Copy Data

RF 480P

Remark

1080i

Alignment and Adjustments

Samsung Electronics 4-9

4-2-8 VIDEO ADJUST 4

ITEM INITIAL DATA

System RF 1

System_VSD_480P 1

System_1080i 2

Shp_Fo_VSD_480P 1

HPF_VSD 3

BPF_VSD 1

Chrm_bdwth_RF 28

Chrm_bdwth_Video 28

Chrm_bdwth_Svideo 30

Chrm_bdwth_DVD 28

IF_Comp_RF 2

IF_Comp_Video 4

IF_Comp_Svideo 5

Range

0 ~ 3

0 ~ 1

0 ~ 7

0 ~ 63

0 ~ 7

EEP-ROM Copy Data

RF 480P

3 (AVS/SV/DVD)

1 (AVS/SV/DVD)

1080i

Remark

fix

IF_Comp_DVD 4

VM_Delay_480P 1

0 ~ 7

0 ~ 3

fix

Alignment and Adjustments

4-10 Samsung Electronics

4-2-9 OPTION

ITEM INITIAL DATA

CRT WIDE

PIP ON

3D-Comb Filter OFF

Blue Screen

OFF

BBE Effect

Auto power On

System CT

Virtual Dolby

OFF

ACS

V chip (CT,CTA)

V chop Area USA

Sub Woofer

OFF

No Sync Mute

DVI

AGC

Tubo Effect

Burst Screen

DW Multi

OFF

OFF OFF

Large

Letter Box

Range

WIDE ↔ 4:3

ON ↔ OFF

CT (EN+SP+ER)→CT-A(E+SP+F)

ON ↔ OFF

USA

ON ↔ OFF

ON ↔ OFF ON ↔ OFF

Large ↔ Double

ON ↔ OFF

HCM4216W,HCM4215W, HCL4715WB,HCM4715W

(PCL5415RB,PCM5415R)

HCM5525WB,PTH5598W

WIDE(4:3)

OFF

USA

OFF

OFF OFF

Large

HCM422W,HCM473WB

(PCL545RB,PCM545R)

HCM553WB

WIDE(4:3)

OFF

USA

OFF

OFF OFF

Double

Alignment and Adjustments

Samsung Electronics 4-11

4-3 Screen Change (When adjusting I2C Bus Geometric items)

1 V SHIFT

2 V LINEARITY

3 H SIZE

6 V SIZE

7 V - S - CORRECTION

PIN PHASE

PIN AMP

5 V ANGLE

9 H SHIFT

10 V BOW

Alignment and Adjustments

4-12 Samsung Electronics

4-4 Other Adjustments

4-4-1 Screen Adjustment

1. Warm up the TV for at least 30 minutes.

2. Select the “ STANDARD” Video mode.

3. Turn to the Video Mode (No Signal) using a remote-control.

4. Connect an oscilloscope to RK,GK,BK.

5. Adjust the VR (VR501, VR531, VR561) screen so that RK, GK, BK pulse is 20Vp-p each. (Turn the R,G,B VR screen fully counterclockwise in the area of each flyback line.)

4-4-2 White Balance Adjustment

1. Select the “STANDARD” video mode.

2. Input 100% white pattern.

3. In the stand-by mode, press the remote-control keys in the following sequence:

4. Warm up the TV for at least 30 minutes.

5. Input a 10-step signal.

6. R-cut off, B-cut off, and G-cut off by pressing the Volume keys.

7. Adjust the low light with viewing the dark side of the screen.

8. Select R-drive, G-drive, and B-drive by pressing the Volume keys.

9. Adjust the high light with viewing the light side of the screen.

10. If necessary, redo adjustments 6~9.

11. Press the Menu key to exit.

4-4-3 Sub-Brightness Adjustment

1. Input a sub-brightness adjustment signal. (TOSHIBA PATTERN)

2. In the stand-by mode, press the remote-control keys in the following sequence :

3. Select SBT by pressing the Volume keys.

4. Adjust so that the 63 step on the right side of the screen is not seen (Use the Volume keys).

5. Press the Menu key to exit.

4-4-4 High Voltage (29KV) Check

PRECAUTION

1. Input a lion head pattern.

2. Select “STANDARD” video mode.

3. Warm up the TV for at least 10 minutes.

4. Use a 1000:1 probe.

ADJUSTMENT

1. Connect the (+) terminal of the 1000:1 probe to the high voltage distributor and the (-) terminal to GND (located on the deflection board).

2. Adjust RR471S (located on the deflection board) so that the digital meter indicates DC 29V ± 0.1V.

4-4-5 F.S. (Fail Safe) Adjustment

Note : The finished product has a well-mounted

VR (RR402S). If necessary, do the F.S. adjustments in the following sequence.

1. Use a digital multimeter.

2. Connect the digital multimeter to the JIG pin (DZ482S) terminals

3. Adjust VR (RR402S) so that the voltage becomes 2.25V.

4. After the adjustments are complete, be sure to mount VR (RR402S) correctly.

Alignment and Adjustments

Samsung Electronics 4-13

4-4-6 F.S. (Fail Safe) Circuit Check

Note : The F.S. Circuit check must be performed

after servicing.

1. Turn on the TV.

2. Select the “STANDARD” video mode.

3. Short F/S Test point (located on the SUB PCB). Then, both sound and picture disappear. (Note: Even if the shorted terminals are removed, both sound and picture do not appear. This proves the F.S. circuit is working. )

4. To restore both sound and picture, turn off the TV and reset it after about 30 seconds.

4-4-7 Static Focus Adjustment

PRECAUTION

1. Select the “STANDARD” video mode.

2. Input a crosshatch pattern.

3. Cover the lenses that are not being adjusted.

4. Connect a convergence jig and read data.

5. Adjust the lens for best focus. (See Fig, 4-1)

STATIC FOCUS (CONTINUED)

Vary the focus pack VR (Red, Blue) on the front cabinet. Adjust the TV for best possible focus around the center of the crosshatch pattern, without losing overall screen balance. Figure Crosshatch Pattern Examine these points together.

4-4-8 Lens Focus Adjustment

PRECAUTIONS

1. Do this adjustment after the static focus adjustment and the tilt adjustment.

2. Select the “STANDARD” video mode. (Contrast:100, Brightness:50)

3. Input a crosshatch pattern.

ADJUSTMENT

1. Loosen the lens screws.

2. Cover the two lenses that are not being adjusted.

3. Adjust the lens, observing the color aberration vertically and horizontally within 3 blocks of the center of the crosshatch pattern.

4. When the lens is turned clockwise, the color aberration will change as follows:

Lens Color Aberration Change R Orange - Crimson G Blue - Red B Purple - Green

5. Green lens adjustment: Set the lens at the point where Blue just changes to Red. If the color aberration is irregular throughout the picture screen, adjust the lens to show Red color aberration (approximately 1~3 mm area) within a 3-block grid around the horizontal center-line. If the color aberration is irregular, adjust the lens as shown in the diagram below. (Accurate alignment of Green is important for overall color quality.)

6. Red lens adjustment Set the Red lens at the point where Orange becomes Crimson.

7. Blue lens adjustment Set the Blue lens at the point where Purple becomes Green.

RED ABERRATION

BLUE ABERRATION

L1, L2 < P

Fig. 4-1 Crosshatch Pattern.

Fig. 4-2 Color Aberration

Examine these points together

Alignment and Adjustments

4-14 Samsung Electronics

1. Select the “STANDARD” video mode.

2. Warm up the set at least for 10 minutes.

3. Enter the Convergence mode by pressing the remote control buttons in the following sequence :

4. Set the Beam Alignment Adjustment CY to Zero magnetic field area.

5. Check the squarewave at the point where the focus is misaligned (Use an audio oscillator).

6. Press the button on the remote control, and a vibrating dot-pattern appears.

7. Adjust the Focus-pack VR for defocusing.

8. Mute the other patterns (R/B) other than G-PATTERN. (Use / buttons on the remote control.)

9. Adjust the 2, 4 polarities of VM-COIL as shown in figure below.

10. Adjust the G-Focus until any light around the core disappears.

11. Adjust G-Focus so that the surrounding flash can disappear from the spot.

12. After G-Focus adjustments are complete, adjust R-Focus as above procedures.

13. The B-CRT adjustments can be omitted because the variance of beam focus is small. (Only Vm-coil is mounted.)

14. Adjust the Focus-pack VR for fine focusing.

15. Press the button on the remote control, and the mode changes to the Convergence Adjustment mode.

16. Press the button on the remote control to return to normal viewing.

4-5 Beam alignment Adjustments

(Creation of CPM Zero Magnet)

(Creation of the 2-pole/4-pole zero magnets)

G-FOCUS

(Varying G-Focus Pack)

G-FOCUS

(When VM 2-Pole Adjustment is completed)

CORE

Varying the 2-pole of VM

Varying the 4-pole of VM

(Positioning the Core in the Center)

(Adjust until the light around the core becomes a circle)

Alignment and Adjustments

Samsung Electronics 4-15

4-6 Hige Voltage Part

4-6-1 PWM REG Circuit

For the existing high voltage REG circuit (input voltage variation type), a dynamic REG response is not provided. So it is difficult for both beam linearity and uniformity in screen size to be maintained on the screen with rapidly changing beams.

A PWM (Pulse Width Modulation) type of high voltage, however, provides the maintenance of beam linearity and uniformity in screen size via a quick response to beam change by performing sync lock every 1H line, and detecting beam fluctuation at 1H line, and then controlling the IC current of high voltage output circuit.

1. High Voltage Fluctuation Detect (DC Detect)

FBT pin 11 detects DC high voltage fluctuation. The detected DC high voltage value is input to PWM IC471 pin1 through R473, VR471, R471, and then it is input to a differential AMP circuit that differentiates the gap after comparing with the reference voltage input to pin2.

2. High Voltage Fluctuation Detect (AC Detect)

To check AC high voltage fluctuation, the output from FBT is detected by using a capacitor inside the high voltage distributor. The detection of AC high voltage fluctuation, a detection of dynamic beam current change is required in order to keep beam linearity and uniformity in size. Regarding the capacitor, a capacity of less than 3000P should be applied to a PWM type. (The existing type needs a capacity of about 6000P.) AC detect circuit eliminates unnecessary high frequency by using C476, D472. Also, AC gain is limited to + / - 0.7V (D472). This AC gain is combined with the detection value of DC high voltage fluctuation by using C478.

3. PWM IC OSC Sync Lock

A PWM type IC needs sync lock for PWM pulse and horizontal scan line. The standard time constant of OSC circuit is determined by C487, R475 (PWM IC pins 5 and 6). And the standard OSC frequency is about 27 kHz . The horizontal frequency of scan line is

31.5kHz(NT), 3375kHz(DTV), 15.75kHz(Interface), so sync lock for this horizontal frequency should be performed using sync lock circuit. The sync lock circuit consists of Q481(Tr KSC815-Y), D479, D478, and C492. The input AFC signal is connected to PWM IC pin 5 through D479 so that it can be negative Trig.

4. Dead Time (HV Protect)

Dead Time (PWM IN pin4) consists of C481, delays high voltage for a certain time to soft start in power on, a x-ray protection circuit. The voltage of Dead Time is detected by FBT pin7 and through DC Feedback. The normal voltage of Dead Time is +27V. When high voltage increases, however, detected voltage is in proportion to high voltage. Then, the detected voltage is applied to ICR01S(TL431). If the voltage is over 2.5V (normal:about 2.25V), TL431 turns ON, the base port of QR401S becomes low, and then an emitter current flows. At this time, a high voltage protection point is set. When QR401S turns ON, high voltage is applied to PWM IC pin4 and then muted.

OSC : 27KHz

AFC Waveform : 31.5KHz(NT)

Locked OSC Waveform : 31.5KHz

Alignment and Adjustments

4-16 Samsung Electronics

5. Output Circuit

The voltages, which are detected form an error detection circuit of PWM IC (Differential AMP) and Dead Time, each is applied to PWM conparator . Due to these detection coltages, Q1, Q2 (Output TR) parallel operate. Q482 (External TR), however, functions as a buffer; natches inpedance between the output port of PWM IC and the final output TR(IRFS640). The PWM pulse (applied to the final output FET (IRFS640 GATE) varies the IC current of high voltage TR(Q473) by adjusting the load impedance of starage Trans (T431). Due to this variation of current, the gain for Q473 emitter pulse changes T444(FBT)makes this emitter pulse became high voltage. Such change keeps both dynamic and static changes fixed. The output waveform of high valtage TR emitter is as shown in the figure below.

6. Paraneters according to beam

To maintain the set high voltage value (31kV), parmaters such as +Ve (DC), Vcp High Voltage change (See the table below).

7. Response Waveform

To reduce unstable high voltage fluctuation, the existing high voltage type REG circuit controls dynamic fluctuation by using C-block capacitor. But, it can't detect actual dynamic fluctuation. Also, its velocity of response to static fluctuation is late because +B power supply changes per

about 1V. A PWM modulation type REG detects static, dynamic high voltage fluctuation for only Ton Time (when the current of the output TR collector flows) each 1H, and modulates the width of PWM pulse. So, this PWM type has better improvement in the characteristic of high voltage REG as compared to the existing type.

8. Application Effects

1) Improvement of horizontal size fluctuation

2) Linearity improved

3) Embodiment of X-ray protection circuit

The figures below show characteristics when a PWM high voltage REG circuit is applied.

Beam

(High voltage )

Factor of high

voltage change

Beam

(High voltage )

Width of FET

Gate Pulse

+ Ve (DC)

Vcp

High

Voltage

Parameters

High Voltage Drive Base Current

PWM Input Waveform of FET GATE

GND

PWM Variation tange

Ton Toff

Beam

High Voltage

High Voltage OFF High Voltage REG ON

BLACK

WHITE

When a Toshiba Pattern is recrived, the screen is displayed as shown in figute side

Existing type

PWM type

+ 67 hidden pages