SAMSUNG TB531VCT1X Service Manual

Television Video Cassette Recorder

Chassis : SCV11F Model: TB531VCT1X/XSA

TB331VDZ1S/XSA

Television Video Cassette Recorder CONTENTS

Precautions Specifications Disassembly and Reassembly

Alignment and Adjustment (Mechanical)

Alignment and Adjustment (Electrical)

Troubleshooting Exploded View and Parts List Electric Parts List Block Diagram PCB Layout Wiring Diagram Schematic Diagrams

10.

11.

12.

ELECTRONICS

Samsung Electronics Co., Ltd. NOV.1998

Printed in Korea

3SCV11F-3115

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)

Samsung Electronics 2-1

2. Specifications

TELEVISION

Colour system PAL/SECAM Multistandard Optional Systems L/L’ (Option), B/G (Option), D/K (Option), I (Option) Number of channels 100 Tuning Range: Off-Air/Cable Hyperband/interband tuner Aerial input 75 Ohms, coaxial cable

VCR

Format VHS standard (PAL/SECAM Option)/MESECAM (Option) /NTSC (playback only) Heads Video: 2 rotary heads, LP (Option), 4 Heads (Option)

Audio/Control: 1 stationary head (linear)

Erase: 1 full track erase head Video system CCIR standard Audio system Mono Luminance FM azimuth recording Colour Down converted subcarrier phase shifted direct recording Wow and flutter (WTD) 0.4% maximum (SP) Frequency response 100Hz - 8 KHz

GENERAL

Power supply 220~240V; 50Hz; Option: 110~260V, 50~60Hz Consumption 14 Inch (80W), 20 Inch (100W), 21 Inch (105W) Audio output power 14 Inch (2.0 watts), 20 Inch, 21 Inch ( 2Watts x 2) Number of loudspeakers 14 Inch (1), 20 Inch, 21 Inch (2) Tube size 14” (37 cm), or 20” (51 cm), 21” (55 cm) Tube type BLACK MATRIX Sockets 1 full RGB SCART: Rear (Option); 1 RCA output (Option): Rear

1 RCA input (audio and video): Front

Earphones (3.5 mm mini-jack)

1 aerial/cable TV coaxial input Dimensions (W x D x H) 14 Inch (362x383x382), 20 Inch (482x465x479), 21 Inch (502x494x498) Weight 14 Inch (12.5kg), 20 Inch (22KG), 21 Inch (25kg) Operating temperature 5°C - 40°C (41°F-104°F) Relative humidity 10%-75%

MEMO

2-2 Samsung Electronics

Disassembly and Reassembly

Samsung Electronics 3-1

3. Disassembly and Reassembly

3-1 Disassembly

3-1-1 Back Cover Removal

Fig. 3-1

1. Remove the screws located on the side of the back cover.

2. Pull the Main Assembly backward and remove it from the front cabinet.

3-1-2 Main Assembly Removal

Disassembly and Reassembly

3-2 Samsung Electronics

Fig. 3-2

1. Release two connectors between sub PCB and Main Assembly.

2. Pull the Main Assembly backward. Remove it from the front cabinet.

3-1-3 Monitor Frame Removal

Disassembly and Reassembly

Samsung Electronics 3-3

Fig. 3-3

1. Remove 2 screws from the Main Assembly. Remove the dust cover.

2. Remove 2 screws from the Deck Assembly. Remove the dust-cover bracket.

Disassembly and Reassembly

3-4 Samsung Electronics

3-1-4 Deck Assembly Removal 3-1-5 Main Assembly Removal

1. Remove 4 screws holding the bottom cover.

2. Remove one screw from Main PCB Assembly. Take out the deck assembly.

1. Remove 2 screws holding the upper chassis housing.

2. Remove 3 screws holding the deck assembly.

3. Lift the deck assembly upward to remove.

Samsung Electronics 4-1

4-1 Deck Parts Locations

4-1-1 Deck (Top View)

5 6

141516

Fig.4-1 Deck Top Parts Location (DX7-A/DX8-A DECK ONLY)

4. Alignments and Adjustments (Mechanical)

1. ARM TENSION FULL ASS’Y

2. BRAKE MAIN “L” ASS’Y

3. GUIDE ROLLER ASS’Y “T”

4. FULL ERASE HEAD

5. GUIDE ROLLER ASS’Y “S”

6. CYLINDER ASS’Y

7. LEVER PINCH COMP ASS’Y

8. LEVER PINCH CAM

9. FULL ACE HEAD AAS’Y

10. UNIT PINCH ROLLER ASS’Y

11. LEVER REVIEW

12. BRAKE SUB “R” ASS’Y

13. REEL DISK “R” ASS’Y

14. GEAR RELAY “T” ASS’Y

15. IDLER ASS’Y

16. GEAR RELAY “S” ASS’Y

17. REEL DISK “L” ASS’Y

18. LEVER JOG ASS’Y (DX8-A/AC ONLY)

19. LEVER REC SWITCH

4-1-2 Deck (Top View)

Alignments and Adjustments (Mechanical)

4-2

Samsung Electronics

465

151617

Fig.4-2 Deck Top Parts Location (DX7-AC/DX8-AC DECK ONLY)

1. ARM TENSION FULL ASS’Y

2. BRAKE MAIN “L” ASS’Y

3. GUIDE ROLLER ASS’Y “T”

4. FULL ERASE HEAD

5. HEAD CLEANER ASS’Y (DX7-AC/DX8-AC ONLY)

6. GUIDE ROLLER ASS’Y “S”

7. CYLINDER ASS’Y

8. LEVER PINCH COMP ASS’Y

9. LEVER PINCH CAM

10. FULL ACE HEAD AAS’Y

11. UNIT PINCH ROLLER ASS’Y

12. LEVER REVIEW

13. BRAKE SUB “R” ASS’Y

14. REEL DISK “R” ASS’Y

15. GEAR RELAY “T” ASS’Y

16. IDLER ASS’Y

17. GEAR RELAY “S” ASS’Y

18. REEL DISK “L” ASS’Y

19. LEVER JOG ASS’Y (DX8-A/AC ONLY)

20. LEVER REC SWITCH

Alignments and Adjustments (Mechanical)

Samsung Electronics 4-3

4-1-3 Deck (Bottom View)

Fig.4-3 Deck Bottom Parts Location

1. LEVER SLIDE PINCH

2. BELT CAPSTAN

3. MOTOR D.D CAPSTAN

4. BRAKE CAPSTAN ASS’Y

5. GEAR LOADING “R” ASS’Y

6. MOTOR CYLINDER

7. GEAR LOADING “L” ASS’Y

8. SLIDE MAIN

9. LEVER REC SWITCH

10. LEVER IDLER CHANGE

11. CLUTCH ASS’Y

12. UNIT LOADING

13. GEAR MASTER

Alignments and Adjustments (Mechanical)

4-4

Samsung Electronics

4-1-4 Housing View

2 3

Fig. 4-4 Housing Parts Location

1. CHASSIS SIDE “L” ASS’Y

2. UPPER CHASSIS

3. CHASSIS SIDE “R” ASS’Y

4. SHAFT ARM ASS’Y

5. HOLDER CASSETTE ASS’Y

6. LEVER DOOR

Alignments and Adjustments (Mechanical)

Samsung Electronics 4-5

4-2 Housing Assembly

4-2-1 Removal from Main Base

1. Remove 3 Screws ① .

2. Lift the Housing AssÕy in the direction of arrow ÒBÓ, while pushing the tab ➁ in the direction of arrow

ÒAÓ. (Refer to detail drawing)

3 SCREWS

MAIN BASE

TAB

"A"

Fig. 4-5 Housing Ass’y Removal from Main Base

Alignments and Adjustments (Mechanical)

4-6

Samsung Electronics

4-2-2 Diassembly

2 SCREWS

UPPER CHASSIS

CHASSIS SIDE "R"

HOLDER

CASSETTE ASS'Y

SHAFT ARM ASS'Y

CHASSIS SIDE "L"

Fig. 4-6 Housing Ass’y Removal

Alignments and Adjustments (Mechanical)

Samsung Electronics 4-7

4-2-3 Upper Chassis Removal

1. Remove 2 Screws ①.

2. Lift the Upper Chassis ➁ in the direction of arrow ÒAÓ.

2 SCREWS

UPPER CHASSIS

"A"

Fig. 4-7 Upper Chassis Removal

Alignments and Adjustments (Mechanical)

4-8

Samsung Electronics

4-2-4 Holder Cassette Ass’y and Chassis Side L/R Removal

1. Lift the Cassette Holder ① in the direction of arrow ÒAÓ (Refer to Fig. A).

2. Remove the Side Chassis ÒLÓ ② and ÒRÓ ➂ from Arm Shaft AssÕy ➃in the direction of arrow ÒBÓ, ÒCÓ

(Refer to Fig. B).

HOLDER CASSETTE ASS'Y

"A"

SHAFT ARM ASS'Y

CHASSIS SIDE "L"

CHASSIS SIDE "R"

SLIDE DAMPER

"B"

<Fig. A>

<Fig. B>

(REASSEMBLY OF CHASSIS SIDE "R" & SHAFT ARM "R")

(SIDE VIEW)

"C"

"D"

SHAFT ARM "R"

Fig. 4-8 Holder Cassette Ass’y and Chassis Side L/R

Alignments and Adjustments (Mechanical)

Samsung Electronics 4-9

4-2-5 Chassis Side “R” Parts Locations

CHASSIS SIDE "R"

(SIDE VIEW "A")

SLIDE DAMPER

LEVER-LID OPENDER

"A"

SPRING-SLIDE DAMPER

SPRING-LID OPENDER

Fig. 4-9 Chassis Side “R” Parts Locations

Note : If you operate the deck when the Cassette AssÕy Holder is removed, the Arm Shaft ÒRÓ and the

Damper Slide are not returned to their original positions. If this happens by accident, push the Damper Slide of Side Chassis ÒRÓ in the direction of arrow ÒDÓ, and return the Damper Slide in the reverse direction of arrow ÒDÓ when the Arm Shaft AssÕy is in eject mode.

Alignments and Adjustments (Mechanical)

4-10

Samsung Electronics

4-2-6 Slide Damper Removal

1. Remove the Slide Damper Spring ①.

2. Push the Stopper ➂ of the Side Chassis ÒRÓ ➃. Move the Damper Slide ➁ in the direction of arrow.

3. Align the Damper Slide ✠ with the chassis side tab (as shown detail drawing).

CHASSIS SIDE "R"

CHASSIS SIDE "R" TAB

SLIDE DAMPER

STOPPER

SLIDE DAMPER

SPRING- SLIDE DAMPER

Fig. 4-10 Slide Damper Removal

Alignments and Adjustments (Mechanical)

Samsung Electronics 4-11

4-3 Cylinder Ass’y

4-3-1 Exploded View of Cylinder Ass’y

ASS'Y MOTOR - ROTOR

ASS'Y - SUB CYLINDER

2 SCREWS

3 SCREWS

2 SCREWS

ASS'Y - MOTOR STATOR

ASS'Y - BASE CYLINDER

SPRING

CARBON TIP

Fig. 4-11 Exploded View of Cylinder Ass’y

Alignments and Adjustments (Mechanical)

4-12

Samsung Electronics

4-3-2 Head Cleaner Ass’y Removal (Only for Deck : DX7-AC/DX8-AC)

1. Release 1 tab ① in the direction of arrow ÒAÓ. (Refer to detail drawing)

2. Lift the Head Cleaner ➁ in the direction of arrow ÒBÓ.

ASS'Y HEAD CLEANER

"B"

TAB

"A"

Fig. 4-12 Head Cleaner Ass’y Removal

Alignments and Adjustments (Mechanical)

Samsung Electronics 4-13

4-3-3 Cylinder Ass’y Removal from Main Base

1. Remove 3 Screws ① holding the Main Base and the Cylinder AssÕy.

2. Lift the Cylinder AssÕy ➁in the direction of arrow.

Note : Do not touch the video heads during removal or installation.

3 SCREWS

CYLINDER ASS'Y

Fig. 4-13 Cylinder Ass’y Removal from Main Base

Alignments and Adjustments (Mechanical)

4-14

Samsung Electronics

4-3-4 Holder FPC Removal

1. Release the Holder FPC tab holding the Cylinder Base ➁ in the direction of arrow.

(Refer to detail drawing)

2. Disconnect the Holder FPC ① from the Cylinder Base ➁.

3. Note : When disconnecting the FPC Holder ① from the Cylinder Base ➁ :

Take care not to disconnect the FPC cable from the FPC Holder (The FPC cable is very short).

HOLDER FPC

CYLINDER BASE

HOLDER FPC

Fig. 4-14 Head Brush and Holder FPC Removal

Alignments and Adjustments (Mechanical)

Samsung Electronics 4-15

CYLINDER SUB ASS'Y

CYLINDER BASE

3 SCREWS

Fig. 4-15 Cylinder Ass’y Removal from Cylinder Base

4-3-5 Cylinder Ass’y Removal from Cylinder Base

1. Remove 3 Screws ① from the Cylinder Base ➁.

2. Lift the Cylinder AssÕy ➂ from the Cylinder Base ➁ in the direction of arrow.

Alignments and Adjustments (Mechanical)

4-16

Samsung Electronics

4-3-6 Motor Stator Removal

1. Remove 2 Screws ①.

2. Remove the Motor Stator ➁ from the Cylinder Sub AssÕy ➄.

3. Note : When disassembling the Motor-Stator, be careful not to loose the carbon-tip and spring.

MOTOR - STATOR

CYLINDER SUB ASS'Y

2SCREWS

SPRING

CARBON TIP

Fig. 4-16 Motor Stator Removal

Alignments and Adjustments (Mechanical)

Samsung Electronics 4-17

4-3-7 Motor Rotor Removal

1. Remove 2 Screws ①.

2. Lift The Motor Rotor②.

MOTOR - ROTOR

DRUM SUB ASS'Y

2 SCREWS

Fig. 4-17 Motor Rotor Removal

Alignments and Adjustments (Mechanical)

4-18

Samsung Electronics

4-3-8 Motor Rotor and Cylinder Sub Ass’y

1. Make sure that phase matching holes of the Motor Rotor and the Cylinder Sub AssÕy are aligned correctly as shown in Fig. 4-18 (Refer to phase matching hole).

2. Secure 2 Screws.

MOTOR - ROTOR

PHASE MATCHING HOLE

DRUM SUB ASS'Y

2 SCREWS

Fig. 4-18 Assembly of Motor Rotor and Cylinder Sub Ass’y

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