SAMSUNG CW30A80SA, CW764AHA, CW30A90SD, CW767AHD Service Manual

COLOR TELEVISION RECEIVER

Chassis : SCT53A Model : CW30A80SA (CW764AHA)

CW30A90SD (CW767AHD)

COLOR TELEVISION RECEIVER CONTENTS

Precautions

Reference Information

Specifications

Disassembly and Reassembly

Alignment and Adjustments

Troubleshooting

Exploded View and Parts List

Electric Parts List

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 peopleÑparticularly childrenÑmight 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 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: 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 unitÕs 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

Òhorizontal disableÓ or Òhold-downÓ.)

Heed the high voltage limits. These include the XÐray 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 manufacturerÕs 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 Òintegral implosionÓ 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 Òin-lineÓ picture tubes are equipped with a permanently attached deflection yoke; do not try to remove such Òpermanently attachedÓ 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 originalÑeven 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 unitÕs 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 instrumentÕs ground lead to the instrument chassis ground before connecting the positive lead; always remove the instrumentÕs ground lead last.

Precautions

Samsung Electronics 1-3

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. Some semiconductor (Òsolid stateÓ) 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 powerÑ 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 Òanti-staticÓ; 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

1-3 Precautions for Electrostatically Sensitive Devices (ESDs)

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 2-1 Abbreviations

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

Loc No.

IC101 IC201 IC601 IC602 IC604 IC802 IC803 IC804 IC805 IC806 ICA01 ICA02 IC201 IC202 IC203 IC204 IC206 IC207 IC208 IC209 IC210 IC212 IC211 IC213 IC601 IC602

No.

1 2 3 4 5 6 7 8

9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

Specification TDA9810 TDA4780

TDA7265

HCF4053BE

SI3050C

KA812 KA7808 KA7809 S727D KA393 CIP3250A VPC3210A TL7705AC SDA9280 SDA9272

SDA9253

SDA9362

74F125

74F541 74F08 MSP3410D 74HC4052D

Description

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

Remarks

Reference Information

Samsung Electronics 2-3

2-3 IC Line Up

Table 2-1 IC Line Up

Reference Information

2-4 Samsung Electronics

Loc No.

IC603

IC604 ICD601 ICD602

IC701

IC702

IC703

IC704

IC901

IC902

IC903

IC905

ICT01

ICT02

IC301

IC403

IC801

IC803

IC804

IC805

IC806

IC501

IC502

IC503

IC504

No.

27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51

Specification TDA7050 TL062C DPL3519A TL062C

TDA6920X

TL062C

SDA30C264 ST24W16 TMS27C040 SAA1300 SDA5273P KM44C1000 TDA8351 TDA8145 STR-S6709 TOP210ES TL431 LTV817B KA7805

TDA6111Q

TDA2030

Description AUDIO AMP OP AMP Dolby Pro Logic Processor OP AMP

7 X 5 Video Matrix Switch

OP AMP

8 bit Micro controller ROMILESS 16K EEPROM 512K * 8 EPROM

MEGATEXT IC DRAM DC-coupled vertical deflection EW SMPS Stand-by SMPS

Photo-Coupler Regulator (5V)

Video Output Amplifier

AMP

Remarks

Table 2-1 IC Line Up

Specifications

Samsung Electronics 3-1

3. Specifications

MODEL

CW-30A80SA (CW764AHA)

O O O O

CW-30A90SD (CW764AHD)

O X

MAIN CHARACTERISTICS

SYSTEM

ANTENNA INPUT

POWER

TUBE

NUMBER OF CHANNELS TUNING RANGE

SOUND OUTPUT

SOCKETS

100 Hz Dolby Pro Logic EPG AV_LINK TUNING COLOR SOUND

CONSUMPTION REQUIREMENTS

FREQUENCY SIZE TYPE

FRONT

BACK (3 SCARTS)

Frequency Synthesizer

PAL, SECAM, NTSC(only AV mode)

NICAM, A2 STEREO, AM

75ohms,Coaxial Cable

180W -

Main Voltage : 230V

Input Range : 220-240V

50Hz/60Hz

30” (76Cm)

12.8:9, 2.5R Invar 100

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

Right : 15W Left : 15W Center : 15W Surround : 15W (L+R)

Right : 15W Left : 15W

- RCA : Input/S-VHS

- Headphone Audio Output

- EXT1 : full RGB Scart / AV-LINK

- EXT2 : Scart (Output Selectable)

- EXT3 : Decoder (Output Selectable)

- Surround SPK Jack

- Rear AMP Jack

Specifications are subject to change.

JUMPER JUMPER

3812-000219 3812-000219

DEL DEL

DEL DEL DEL DEL DEL DEL DEL DEL DEL DEL DEL DEL DEL DEL DEL DEL DEL DEL DEL DEL DEL DEL DEL DEL DEL DEL DEL DEL DEL

C-FILM 103 C-FILM 103

C-AL 1000 mF

C-FILM 104

C-AL 1000mF

C-FILM 104 C-FILM 104

C-AL 1000mF

C-AL 1 mF

C-AL 100mF

C-AL 1mF

C-AL 10 mF

IC;TDA7265

IC;4053B

JUMPER JUMPER JUMPER 1/2 1.8K 1/2 1.8K 1/2 1.8K 1/2 1.8K

1/2 4.7 1/8 10K 1/8 300 1/8 300

JUMPER JUMPER

1/8 10K

2301-000380 2301-000380 2401-000192 2301-000530 2401-000192 2301-000530 2301-000530 2401-000192 2401-000603 2401-000318 2401-000603 2401-002265 3711-000900

AA96-50279A

0801-000961 3812-000219 3812-000219 3812-000219 2001-001055 2001-001055 2001-001055 2001-001055 2001-001146 2001-000290 2001-000628 2001-000628 3812-000219 3812-000219 2001-000290

Specifications

3-2 Samsung Electronics

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

CW-30A80A : 3D SOUND

SPECIFICATION

CODE NO

Loc No.

C601 C602 C612 C613 C614 C615 C616 C617 C618 C619 C620

C635 CN17 IC602 IC604

J013

J168

J169

R610

R611

R613

R614

R615

R616

R617

R618

R619

R620

R629

J061

J062

CW-30A90SD : DOLBY SOUND

SPECIFICATION CODE NO

4P, JACK

RCA-2P

AA63-40276A

3722-001158

Loc No.

CN706 CN707

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

Specifications

Samsung Electronics 3-3

CW-30A80A : 3D SOUND

SPECIFICATION

CODE NO

CW-30A90SD : DOLBY SOUND

SPECIFICATION CODE NO

RCA-5P 3722-001157

Disassembly and Reassembly

Samsung Electronics 4-1

4. Disassembly and Reassembly

4-1 Back Cover Removal

4-2 Speaker Removal

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

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

Disassembly and Reassembly

4-2 Samsung Electronics

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.

Alignment and Adjustments

Samsung Electronics 5-1

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 color- bar 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.

+ 32 hidden pages