SAMSUNG CW30A80SA, CW764AHA, CW30A90SD, CW767AHD Service Manual

COLOR TELEVISION RECEIVER

Chassis : SCT53A

Model : CW30A80SA (CW764AHA)

CW30A90SD (CW767AHD)

COLOR TELEVISION RECEIVER

CONTENTS

1. Precautions

2. Reference Information

3. Specifications

4. Disassembly and Reassembly

5. Alignment and Adjustments

6. Troubleshooting

7. Exploded View and Parts List

8. Electric Parts List

9. Wiring Diagram

10. Schematic Diagrams

Precautions

1. Precautions

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

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.

									(READING SHOULD
						LEAKAGE			NOT BE ABOVE
DEVICE						CURRENT				0.5mA)
UNDER						TESTER
TEST
		TEST ALL
	EXPOSED METAL
		SURFACES
2-WIRE CORD
ALSO TEST WITH
PLUG REVERSED
(USING AC ADAPTER											EARTH
PLUG AS REQUIRED)										GROUND

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.

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Precautions

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.

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Precautions

1-2 Servicing Precautions

Warning1: 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.

Warning2: An electrolytic capacitor installed with the wrong polarity might explode.

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.

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Precautions

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.

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Reference Information

2. Reference Information

2-1 Tables of Abbreviations and Acronyms

Table 2-1 Abbreviations

A	Ampere	MV	Megavolt
Ah	Ampere-hour	MW	Megawatt
Å	Angstrom	MΩ	Megohm
dB	Decibel	m	Meter
dBm	Decibel Referenced to One	µA	Microampere
	Milliwatt	µF	Microfarad
°C	Degree Celsius	µH	Microhenry
°F	Degree Fahrenheit	µm	Micrometer
°K	degree Kelvin	µs	Microsecond
F	Farad	µW	Microwatt
G	Gauss	mA	Milliampere
GHz	Gigahertz	mg	Milligram
g	Gram	mH	Millihenry
H	Henry	mI	Milliliter
Hz	Hertz	mm	Millimeter
h	Hour	ms	Millisecond
ips	Inches Per Second	mV	Millivolt
kWh	Kilowatt-hour	nF	Nanofarad
kg	Kilogram	Ω	Ohm
kHz	Kilohertz	pF	Picofarad
kΩ	Kilohm	Ib	Pound
km	Kilometer	rpm	Revolutions Per Minute
km/h	Kilometer Per Hour	rps	Revolutions Per Second
kV	Kilovolt	s	Second (Time)
kVA	Kilovolt-ampere	V	Volt
kW	Kilowatt	VA	Volt-ampere
I	Liter	W	Watt
MHz	Megahertz	Wh	Watt-hour

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Reference Information

Table 2-1 Abbreviations

ABL		Automatic Brightness Limiter		I/O		Input/output
AC		Alternating Current		L		Left
ACC		Automatic Chroma Control		L		Low
AF		Audio Frequency		LED		Light Emitting Diode
AFC		Automatic Frequency Control		LF		Low Frequency
AFT		Automatic Fine Tuning		MOSFET		Metal-Oxide-Semiconductor-Field-Effect-Tr
AGC		Automatic Gain Control		MTS		Multi-channel Television Sound
AM		Amplitude Modulation		NAB		National Association of Broadcasters
ANSI		American National Standards Institute		NEC		National Electric Code
APC		Automatic Phase Control		NTSC		National Television Systems Committee
APC		Automatic Picture Control		OSD		On Screen Display
A/V		Audio-Video		PCB		Printed Circuit Board
AVC		Automatic Volume Control		PLL		Phase-Locked Loop
BAL		Balance		PWM		Pulse Width Modulation
BPF		Bandpass Filter		QIF		Quadrature Intermediate Frequency
B-Y		Blue-Y		R		Right
CATV		Community Antenna Television (Cable TV)		RC		Resistor & Capacitor
CB		Citizens Band		RF		Radio Frequency
CCD		Charge Coupled Device		R-Y		Red-Y
CCTV		Closed Circuit Television		SAP		Second Audio Program
Ch		Channel		SAW		Surface Acoustic Wave(Filter)
CRT		Cathode Ray Tube		SIF		Sound Intermediate Frequency
CW		Continuous Wave		SMPS		Switching Mode Power Supply
DC		Direct Current		S/N		Signal/Noise
DVM		Digital Volt Meter		SW		Switch
EIA		Electronics Industries Association		TP		Test Point
ESD		Electrostatic Discharge		TTL		Transistor Transistor Logic
ESD		Electrostatically Sensitive Device		TV		Television
FBP		Feedback Pulse		UHF		Ultra High Frequency
FBT		Flyback Transformer		UL		Underwriters Laboratories
FF		Flip-Flop		UV		Ultraviolet
FM		Frequency Modulation		VCD		Variable-Capacitance Diode
FS		Fail Safe		VCO		Voltage Controlled Oscillator
GND		Ground		VCXO		Voltage Controlled Crystal Oscillator
G-Y		Green-Y		VHF		Very High Frequency
H		High		VIF		Video Intermediate Frequency
HF		High-Frequency		VR		Variable Resistor
HI-FI		High Fidelity		VTR		Video Tape Recorder
IC		Inductance-Capacitance		VTVM		Vacuum Tube Voltmeter
IC		Integrated Circuit		TR		Transistor
IF		Intermediate Frequency

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Reference Information

2-3 IC Line Up

Table 2-1 IC Line Up

Loc No.		No.		Specification
IC101		1		TDA9810
IC201		2		TDA4780
IC601		3		TDA7265
IC602		4
IC604		5		HCF4053BE
IC802		6		SI3050C
IC803		7
IC804		8		KA812
IC805		9		KA7808
IC806		10		KA7809
ICA01		11		S727D
ICA02		12		KA393
IC201		13		CIP3250A
IC202		14		VPC3210A
IC203		15		TL7705AC
IC204		16		SDA9280
IC206		17		SDA9272
IC207		18		SDA9253
IC208		19
IC209		20		SDA9362
IC210		21		74F125
IC212		22
IC211		23		74F541
IC213		24		74F08
IC601		25		MSP3410D
IC602		26		74HC4052D

Description

Remarks

Multi standard VIF-PLL with QSS-IF and AM demodulator

RGB Video Processor

25W+25W Stereo Amplifier with Mute & SY-BY

Audio-Switching

Low-Drip Regulator (5V)

Regulator (12V)

Regulator (8V)

Regulator (9V)

AUTO PLUS

OP AMP

Component Interface Processor

Video Processor

Power-On Reset Generator

Display Processor

VIP

Memory

Digital Deflection controller

Buffer

Buffer

AND-Gate

Multistandard Sound Processor

Audio Switching

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Reference Information

Table 2-1 IC Line Up

Loc No.

No.

Specification

Description

Remarks

IC603

27

TDA7050

AUDIO AMP

IC604

28

TL062C

OP AMP

ICD601

29

DPL3519A

Dolby Pro Logic Processor

ICD602

30

TL062C

OP AMP

IC701

31

TDA6920X

7 X 5 Video Matrix Switch

IC702

32

IC703

33

TL062C

OP AMP

IC704

34

IC901

35

SDA30C264

8 bit Micro controller ROMILESS

IC902

36

ST24W16

16K EEPROM

IC903

37

TMS27C040

512K * 8 EPROM

IC905

38

SAA1300

ICT01

39

SDA5273P

MEGATEXT IC

ICT02

40

KM44C1000

DRAM

IC301

41

TDA8351

DC-coupled vertical deflection

IC403

42

TDA8145

EW

IC801

43

STR-S6709

SMPS

IC803

44

TOP210ES

Stand-by SMPS

IC804

45

TL431

IC805

46

LTV817B

Photo-Coupler

IC806

47

KA7805

Regulator (5V)

IC501

48

TDA6111Q

Video Output Amplifier

IC502

49

IC503

50

IC504

51

TDA2030

AMP

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Specifications

3. Specifications

MODEL

CW-30A80SA (CW764AHA)

CW-30A90SD (CW764AHD)

100 Hz

O

O

MAIN

Dolby Pro Logic

O

X

CHARACTERISTICS

EPG

O

-

AV_LINK

O

-

TUNING

Frequency Synthesizer

SYSTEM

COLOR

PAL, SECAM, NTSC(only AV mode)

SOUND

NICAM, A2 STEREO, AM

ANTENNA INPUT

75ohms,Coaxial Cable

CONSUMPTION

180W

-

POWER

REQUIREMENTS

Main Voltage : 230V

Input Range : 220-240V

FREQUENCY

50Hz/60Hz

TUBE

SIZE

30” (76Cm)

TYPE

12.8:9, 2.5R Invar

NUMBER OF CHANNELS

100

TUNING RANGE

VHF: 2 ~ 12, UHF : 21 ~ 69, Cable : S1 ~ S41

Right

: 15W

SOUND OUTPUT

Left

: 15W

Right

: 15W

Center

: 15W

Left

: 15W

Surround : 15W (L+R)

- RCA : Input/S-VHS

FRONT

- Headphone Audio Output

SOCKETS

- EXT1 : full RGB Scart / AV-LINK

- EXT2 : Scart (Output Selectable)

BACK (3 SCARTS)

- EXT3 : Decoder (Output Selectable)

- Surround SPK Jack

- Rear AMP Jack

Specifications are subject to change.

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3-1

Specifications

3-1 3D Sound Option Table (Main Board)

Loc No.

CW-30A80A : 3D SOUND

CW-30A90SD : DOLBY SOUND

SPECIFICATION

CODE NO

SPECIFICATION

CODE NO

C601

DEL

C-FILM 103

2301-000380

C602

DEL

C-FILM 103

2301-000380

C612

DEL

C-AL 1000 μF

2401-000192

C613

DEL

C-FILM 104

2301-000530

C614

DEL

C-AL 1000μF

2401-000192

C615

DEL

C-FILM 104

2301-000530

C616

DEL

C-FILM 104

2301-000530

C617

DEL

C-AL 1000μF

2401-000192

C618

DEL

C-AL 1 μF

2401-000603

C619

DEL

C-AL 100μF

2401-000318

C620

DEL

C-AL 1μF

2401-000603

C635

DEL

C-AL 10 μF

2401-002265

CN17

DEL

3P

3711-000900

IC602

DEL

IC;TDA7265

AA96-50279A

IC604

DEL

IC;4053B

0801-000961

J013

DEL

JUMPER

3812-000219

J168

DEL

JUMPER

3812-000219

J169

DEL

JUMPER

3812-000219

R610

DEL

1/2 1.8K

2001-001055

R611

DEL

1/2 1.8K

2001-001055

R613

DEL

1/2 1.8K

2001-001055

R614

DEL

1/2 1.8K

2001-001055

R615

DEL

1/2 4.7

2001-001146

R616

DEL

1/8 10K

2001-000290

R617

DEL

1/8 300

2001-000628

R618

DEL

1/8 300

2001-000628

R619

DEL

JUMPER

3812-000219

R620

DEL

JUMPER

3812-000219

R629

DEL

1/8 10K

2001-000290

J061

JUMPER

DEL

3812-000219

J062

3812-000219

JUMPER

DEL

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Specifications

3-2 3D Sound Option Table (AV-Terminal Board)

Loc No.

CW-30A80A : 3D SOUND

CW-30A90SD : DOLBY SOUND

SPECIFICATION

CODE NO

SPECIFICATION

CODE NO

CN706

4P, JACK

AA63-40276A

CN707

RCA-5P

3722-001157

RCA-2P

3722-001158

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Disassembly and Reassembly

4. Disassembly and Reassembly

4-1 Back Cover Removal

1. After removing the 7 screws, pull the cabinet backwards.

1

7

6

2

3

5

4

4-2 Speaker Removal

1. Loosen the 4 screws and remove the Speaker Holders.

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4-1

Disassembly and Reassembly

4-3 CRT Removal

1.Spread a soft mat on the floor. Place the TV set face down.

2.Remove the 4 screws mounting the CRT to the front cabinet.

3.Lift the CRT.

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Alignment and Adjustments

5. Alignment and Adjustments

5-1 General Alignment Instructions

1.Usually, a color TV-VCR needs only slight touch-up adjustment upon installation. Check the basic characteristics such as height, horizontal and vertical sync and focus.

2.Observe the picture for good black and white details. There should be objectionable color shading; if color shading is present, demagnetize, perform purity and convergence adjustments described below.

3.Use the specified test equipment or its equivalent.

4.Correct impedance matching is essential.

5.Avoid overload. Excessive signal from a sweep generator might overload the front-end of the TV. When inserting signal markers, do not allow the marker generator to distort test results.

6.Connect the TV only to an AC power source with voltage and frequency as specified on the backcover nameplate.

7.Do not attempt to connect or disconnect any wires while the TV is turned on. Make sure that the power cord is disconnected before replacing any parts.

8.To protect against shock hazard, use an isolation transformer.

5-2 Automatic Degaussing

A degaussing coil is mounted around the picture tube, so that external degaussing after moving the TV should be unnecessary. But the receiver must be properly degaussed upon installation.

The degaussing coil operates for about 1 second after the power is switched ON. If the set is moved or turned in a different direction, the power should be OFF for at least 10 minutes.

If the chassis or parts of the cabinet become magnetized, poor color purity will result. If this happens, use an external degaussing coil. Slowly move the degaussing coil around the faceplate of the picture tube and the sides and front of the receiver. Slowly withdraw the coil to a distance of about 6 feet before turning power OFF.

If color shading persists, perform the following Color purity and Convergence adjustments.

5-3 High voltage Check

CAUTION: There is no high voltage adjustment on this chassis. The B+ power supply should be +135 volts

(with full colorbar input and normal picture level).

1.Connect a digital voltmeter to the second anode of the picture tube.

2.Turn on the TV. Set the Brightness and Contrast controls to minimum (zero beam current).

3.Adjust the Brightness and contrast controls to both extremes. Ensure that the high voltage does not exceed 32 KV under any conditions.

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