GOLDSTAR XBS448 Service Manual

CONTENTS

SECTION 1 . . . . SUMMARY

SECTION 2 . . . . CABINET & MAIN CHASSIS

SECTION 3 . . . . ELECTRICAL

SECTION 4 . . . . MECHANISM OF VCR PART

SECTION 5 . . . . MECHANISM OF DVD PART

SECTION 6 . . . . REPLACEMENT PARTS LIST

1-2

SECTION 1

SUMMARY

CONTENTS

PRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRODUCTS ............. 1-3

SERVICING PRECAUTIONS .................................................................................................. 1-4

• General Servicing Precautions

• Insulation Checking Prodedure

• Electrostatically Sensitive Devices

1-3

IMPORTANT SAFETY NOTICE

This manual was prepared for use only by properly trained audio-video service technicians.

When servicing this product, under no circumstances should the original design be modified or altered without permission from ZENITH Electronics Corporation. All components should be replaced only with types identical to those in the original circuit and their physical location, wiring and lead dress must conform to original layout upon completion of repairs.

Special components are also used to prevent x-radiation, shock and fire hazard. These components are indicated by the letter “x” included in their component designators and are required to maintain safe performance. No deviations are allowed without prior approval by ZENITH Electronics Corporation.

Circuit diagrams may occasionally differ from the actual circuit used. This way, implementation of the latest safety and performance improvement changes into the set is not delayed until the new service literature is printed.

CAUTION: Do not attempt to modify this product in any way. Never perform customized installations without manufacturer’s approval. Unauthorized modifications will not only void the warranty, but may lead to property damage or user injury.

Service work should be performed only after you are thoroughly familiar with these safety checks and servicing guidelines.

GRAPHIC SYMBOLS

The exclamation point within an equilateral triangle is intended to alert the service personnel to important safety information in the service literature.

The lightning flash with arrowhead symbol within an equilateral triangle is intended to alert the service personnel to the presence of noninsulated “dangerous voltage” that may be of sufficient magnitude to constitute a risk of electric shock.

The pictorial representation of a fuse and its rating within an equilateral triangle is intended to convey to the service personnel the following fuse replacement caution notice:

CAUTION: FOR CONTINUED PROTECTION AGAINST RISK OF FIRE, REPLACE ALL FUSES WITH THE SAME TYPE AND RATING AS MARKED NEAR EACH FUSE.

SERVICE INFORMATION

While servicing, use an isolation transformer for protection from AC line shock. After the original service problem has been corrected, make a check of the following:

FIRE AND SHOCK HAZARD

1. Be sure that all components are positioned to avoid a possibility of adjacent component shorts. This is especially important on items trans-ported to and from the repair shop.

2. Verify that all protective devices such as insulators, barriers, covers, shields, strain reliefs, power supply cords, and other hardware have been reinstalled per the original design. Be sure that the safety purpose of the polarized line plug has not been defeated.

3. Soldering must be inspected to discover possible cold solder joints, solder splashes, or sharp solder points. Be certain to remove all loose foreign particles.

4. Check for physical evidence of damage or deterioration to parts and components, for frayed leads or damaged insulation (including the AC cord), and replace if necessary.

5. No lead or component should touch a high current device or a resistor rated at 1 watt or more. Lead tension around protruding metal surfaces must be avoided.

6. After reassembly of the set, always perform an AC leakage test on all exposed metallic parts of the cabinet (the channel selector knobs, antenna terminals, handle and screws) to be sure that set is safe to operate without danger of electrical shock. DO NOT USE A LINE ISOLATION TRANSFORMER DURING THIS TEST. Use an AC voltmeter having 5000 ohms per volt or more sensitivity in the following manner: Connect a 1500 ohm, 10 watt resistor, paralleled by a .15 mfd 150V AC type capacitor between a known good earth ground water pipe, conduit, etc.) and the exposed metallic parts, one at a time. Measure the AC voltage across the combination of 1500 ohm resistor and .15 mfd capacitor. Reverse the AC plug by using a non-polarized adaptor and repeat AC voltage measurements for each exposed metallic part. Voltage measured must not exceed 0.75 volts RMS. This corresponds to 0.5 milliamp AC. Any value exceeding this limit constitutes a potential shock hazard and must be corrected immediately.

TIPS ON PROPER INSTALLATION

1. Never install any receiver in a closed-in recess, cubbyhole, or closely fitting shelf space over, or close to, a heat duct, or in the path of heated air flow.

2. Avoid conditions of high humidity such as: outdoor patio installations where dew is a factor, near steam radiators where steam leakage is a factor, etc.

3. Avoid placement where draperies may obstruct venting. The customer should also avoid the use of decorative scarves or other coverings that might obstruct ventilation.

4. Wall- and shelf-mounted installations using a commercial mounting kit must follow the factory-approved mounting instructions. A product mounted to a shelf or platform must retain its original feet (or the equivalent thickness in spacers) to provide adequate air flow across the bottom. Bolts or screws used for fasteners must not touch any parts or wiring. Perform leakage tests on customized installations.

5. Caution customers against mounting a product on a sloping shelf or in a tilted position, unless the receiver is properly secured.

6. A product on a roll-about cart should be stable in its mounting to the cart. Caution the customer on the hazards of trying to roll a cart with small casters across thresholds or deep pile carpets.

7. Caution customers against using extension cords. Explain that a forest of extensions, sprouting from a single outlet, can lead to disastrous consequences to home and family.

PRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRODUCTS

A.C. Voltmeter

Good Earth Ground such as the Water Pipe, Conduit, etc.

0.15uF

1500 OHM

10 WATT

Place this probe on each exposed metal part.

1-4

SERVICING PRECAUTIONS

CAUTION : Before servicing the COMBI HOME THEATER SYSTEM covered by this service data and its supplements and addends, read and follow the

SAFETY PRECAUTIONS.

NOTE

: if unforeseen circumstances create conflict between the following servicing precautions and any of the safety precautions in this publications, always follow the safety precautions.

Remembers Safety First:

General Servicing Precautions

1. Always unplug the COMBI HOME THEATER SYSTEM AC

power cord from the AC power source before: (1) Removing or reinstalling any component, circuit board,

module, or any other assembly.

(2) Disconnection or reconnecting any internal electrical

plug or other electrical connection.

(3) Connecting a test substitute in parallel with an elec-

trolytic capacitor. Caution : A wrong part substitution or incorrect polarity installation of electrolytic capacitors may result in an explosion hazard.

2. Do not spray chemicals on or near this COMBI HOME

THEATER SYSTEM or any of its assemblies.

3. Unless specified otherwise in this service data, clean

electrical contacts by applying an appropriate contact cleaning solution to the contacts with a pipe cleaner, cotton-tipped swab, or comparable soft applicator. Unless specified otherwise in this service data, lubrication of contacts is not required.

4. Do not defeat any plug/socket B+ voltage interlocks with

whitch instruments covered by this service manual might be equipped.

5. Do not apply AC power to this COMBI HOME THEATER

SYSTEM and/or any of its electrical assemblies unless all solid-state device heat sinks are cerrectly installed.

6. Always connect test instrument ground lead to the

appropriate ground before connection the test instrument positive lead. Always remove the test instrument ground lead last.

Insulation Checking Procedure

Disconnect the attachment plug from the AC outlet and turn the power on. Connect an insulation resistance meter(500V) to the blades of the attachment plug. The insulation resistance between each blade of the attachment plug and accessible conductive parts (Note 1) should be more than 1Mohm. Note 1 : Accessible Conductive Parts including Metal panels, Input terminals, Earphone jacks, etc.

Electrostatically Sensitive (ES) Devices

Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components commonly are called Electrostatically Sensitive (ES) Devices. Examples of typical ES devices are integrated circuits and some field effect transistors and semiconductor chip components. The following techniques should be used to help reduce the incidence of component damage caused by static electricity.

1. Immediately before handling any semiconductor component or semiconductor-equipped assembly, drain off any electrostatic charge on your body by touching a known earth ground. Alternatively, obtain and wear a commercially available discharging wrist strap device, which should be removed for potential shock reasons prior to applying power to the unit under test.

2. After removing an electrical assembly equipped with ES devices, place the assembly on a conductive surface such as aluminum foil, to prevent electrostatic charge buildup or exposure of the assembly.

3. Use only a grouned-tip soldering iron to solder or unsolder ES devices.

4. Use only an anti-static solder removal device. Some solder removal devices not classified a “anti-static” can generate electrical charges sufficient to damage ES devices.

5. Do not use freon-propelled chemicals. These can generate electrical charge sufficient to damage ES devices.

6. Do not remove a replacement ES device from its protec tive package until immediately before you are ready to install it. (Most replacement ES devices are packaged with leads electrically shorted together by conductive foam, aluminum foil, or comparable conductive material).

7. Immediately before removing the protective material from the leads of a replacement ES device, touch the protective material to the chassis or circuit assembly into which the device will be installed.

Caution : Be sure no power is applied to the chassis or circuit, and observe all other safety precautions.

8. Minimize bodily motions when handling unpackaged replacement ES devices. (Normally harmless motion such as the brushing together of your clothes fabric or the lifting of your foot from a carpeted floor can generate static electricity sufficient to damage an ES device.)

2-1

SECTION 2

CABINET & MAIN CHASSIS

CONTENTS

EXPLODED VIEWS .....................................................................................................................2-2

1. Cabinet and Main Frame Section ...........................................................................................2-2

2. Woofer Speaker Section (LSH-C640W)..................................................................................2-3

3. Speaker Cener Section (LSH-C640C) ....................................................................................2-4

4. Speaker Rear/Front Section (LSH-C640T) .............................................................................2-5

5. Packing Accessory Section ....................................................................................................2-6

2-2

EXPLODED VIEWS

1. Cabinet and Main Frame Section

BCD

468

471

467

300

264

453

A48

263

457

266

462

A44

261A

330

261A

452

467

251

252

250

467

469

323

473

470

A46

457

A00

471

260

262

322

A46A

A26

276

A50

261

276B

274

261A

283

286

285

280

452

A43

284

287

277

2-3

2. Woofer Speaker Section (LHS-C640W)

952

953

955

951

954

A900

956

950

2-4

3. Speaker Center Section (LHS-C640C)

A700

755

750

752

751

754

753

756

2-5

4. Speaker Rear/Front Section (LHS-C640T)

852

853

A800

855

854

850

851

856

857

2-6

5. Packing Accessory Section

810

CABLE SET ASS'Y, RF

806

CABLE, COAXIAL

822

CABLE, DIN

808

BATTERY

900

REMOCON

811

PLUG ASS'Y 1WAY(YELLOW)

812

PLUG ASS'Y 2WAY

820 PLUG ASS'Y 1WAY(BLACK)

824

ANTENNA LOOP(AM)

825

ANTENNA (FM)

OWNER'S MANUAL

801

SHEET

804

PACKING, CASING

803

PACKING, CASING

803A

PACKING, CASING

803B

803C

PACKING, CASING

BOX

802

OPTIONAL PARTS

3-1

SECTION 3

ELECTRICAL

CONTENTS

OVERALL WIRING DIAGRAM .............................3-2

VCR PART

ELECTRICAL ADJUSTMENT PROCEDURES

...........................................................3-3

ELECTRICAL TROUBLESHOOTING

GUIDE ............................................................................3-4

1. POWER(SMPS) CIRCUIT.......................................3-4

2. SYSTEM/KEY CIRCUIT..........................................3-6

3. SERVO CIRCUIT ....................................................3-7

4. OSD CIRCUIT .........................................................3-9

5. Y/C CIRCUIT.........................................................3-10

6. TUNER/IF CIRCUIT ..............................................3-14

7. Hi-Fi CIRCUIT .......................................................3-16

BLOCK DIAGRAMS ...............................................3-18

1. POWER(SMPS) BLOCK DIAGRAM 1 .................3-18

2. POWER(SMPS) BLOCK DIAGRAM 2 .................3-20

3. Y/C BLOCK DIAGRAM ........................................3-22

4. NORMAL AUDIO BLOCK DIAGRAM ..................3-24

5. Hi-Fi BLOCK DIAGRAM ......................................3-26

6. SYSTEM BLOCK DIAGRAM ...............................3-28

CIRCUIT DIAGRAMS .............................................3-30

1. POWER(SMPS) CIRCUIT DIAGRAM 1 ...............3-30

2. POWER(SMPS) CIRCUIT DIAGRAM 2 ...............3-32

3. JACK/TUNER CIRCUIT DIAGRAM .....................3-34

4. A/V CIRCUIT DIAGRAM.......................................3-36

5. Hi-Fi, DIGEST CIRCUIT DIAGRAM .....................3-38

6. SYSTEM CIRCUIT DIAGRAM..............................3-40

7. KEY CIRCUIT DIAGRAM .....................................3-42

• WAVEFORMS .........................................................3-44

• CIRCUIT VOLTAGE CHART ..................................3-46

PRINTED CIRCUIT DIAGRAMS ........................3-48

1. MAIN P.C.BOARD ................................................3-48

2. POWER P.C.BOARD............................................3-50

3. KEY 1(LEFT) P.C.BOARD....................................3-52

4. KEY 2(RIGHT) P.C.BOARD..................................3-52

DVD & AMP PART

ELECTRICAL TROUBLESHOOTING GUIDE

..........................................................................3-54

1. SYSTEM OPERATION FLOW..............................3-54

2. TEST & DEBUG FLOW........................................3-55

3. AUDIO µ-COM CIRCUIT(DVD & AMP)................3-63

DETAILS AND WAVEFORMS ON SYSTEM TEST AND DEBUGGING

..................3-62

1. SYSTEM 27MHZ CLOCK,

RESET, FLASH R/W SIGNAL ..............................3-62

2. SDRAM CLOCK ...................................................3-64

3. TRAY OPEN/CLOSE SIGNAL..............................3-64

4. SLED CONTROL RELATED SIGNAL

(NO DISC CONDITION)........................................3-66

5. LENS CONTROL RELATED SIGNAL

(NO DISC CONDITION)........................................3-66

6. LASER POWER CONTROL RELATED

SIGNAL(NO DISC CONDITION) ..........................3-67

7. DISC TYPE JUDGEMENT WAVEFORMS ...........3-67

8. FOCUS ON WAVEFORMS ...................................3-69

9. SPINDLE CONTROL WAVEFORMS

(NO DISC CONDITION)........................................3-70

10. TRACKING CONTROL RELATED

SIGNAL(SYSTEM CHECKING) .........................3-71

11. RF WAVEFORM ..................................................3-72

12. MT1379 VIDEO OUTPUT WAVEFORMS...........3-72

13. AUDIO OUTPUT FROM AUDIO DAC ................3-74

14. DVD & AMP WAVEFORMS................................3-75

BLOCK DIAGRAMS ...............................................3-76

1. OVERALL BLOCK DIAGRAM .............................3-76

2. SERVO BLOCK DIAGRAM ..................................3-77

3. MPEG & MEMORY BLOCK DIAGRAM...............3-78

4. VIDEO & AUDIO BLOCK DIAGRAM...................3-79

5. DVD & AMP BLOCK DIAGRAM ..........................3-80

CIRCUIT DIAGRAMS .............................................3-81

1. MPEG CIRCUIT DIAGRAM..................................3-81

2. RF & SERVO CIRCUIT DIAGRAM ......................3-83

3. AUDIO, µ-COM

CIRCUIT DIAGRAM(DVD & AMP) .......................3-85

4. DIGITAL AMP CIRCUIT

DIAGRAM (DVD & AMP)......................................3-87

5. PWM & CODEIC

CIRCUIT DIAGRAM (DVD & AMP)......................3-89

6. INTERFACE

CIRCUIT DIAGRAM (DVD & AMP)......................3-91

• CIRCUIT VOLTAGE CHART ..................................3-93

PRINTED CIRCUIT DIAGRAMS ........................3-97

1. DVD & AMP P.C.BOARD .....................................3-97

3-2

OVERALL WIRING DIAGRAM

PMC01

CFG

CAP Vcc

5.2VA

CAP REV’H’

V-limit

MOTOR GND

S.GND

DRUM(L/M)Vcc

CAP CTL

L/M CONTROL

DPG/FG

DRUM CTL

P3D01

SP PB A

SP REC

SP PB B

EP PB B

EP REC

EP PB A

HiFi PB A

HiFi REC

HiFi PB B

PVS01 PSV01

GND

5.3VA

GND

3.8VA

GND

13VA

GND

33VA

GND

-29VA

FD(-)

FD(+)

PSW01

32VA

32VA GND

GND

PWR SENSE

123456789

PDM01

H FM_VCC

RF_VCC

LD_DVD

MD_DVD

VR_DVD

GND_PD

VRBF

FOCUS+

TRACKING-

TRACKING+

FOCUS-

SW_PDIC

GND_LCD

LD_CD

MD_CD

VR_CD

123456789

10111213141516171819202122

123456789

10111213141516171819202122

PV601 P6M01

KEY RETURN 1

KEY RETURN 2

5.3VA VIDEO IN

GND

AUDIO ’L’ IN

GND

AUDIO ’R’ IN

GND

FD(-)

-27VA

FD(+)

123456789

101112

123456789

101112

PV602 P6M02

REMOCON

GND

FLD CLOCK

FLD DATA

FLD ENA

VOLUME DOWN

VOLUME UP

1234567

PDM03

SPM -

SPM +

FM -

FM +

LM -

LM +

SW(OPEN)

SW(CLOSE)

GND

SW(LOADIN)

GND

123456789

P3D02

CTL(+)

CTL(-)

A/E(+)

A/E(-)

A.REC

A.PB

GND

FULL ERASE

P3D03

5.3VA

NC(-9V)

REG 8V(M)

GND(M)

REG 9V(+9V)

A. GND

REG 3.3V

D. GND

REG 3.3V

A.GND

D.GND

PDV02PVD01

DVD V.IN

GND

DVD A.L IN

GND

DVD A.R IN

GND

VCR A.L OUT

VCR A.R OUT

GND

Pb/B

Y/G

Pr/R

PDV02PVD02

DVD ENA

GND

DVD DATA OUT

DVD DATA IN

DVD CLOCK

DVD RESET

AMP DATA IN

AMP CLOCK

GND

AMP ENA

AMP DATA OUT

AMP RESET

PDV02PVD02

GND(D)

KEY RTN 1

GND(A)

F.A.R.IN

GND(A)

F.A.L.IN

GDN(D)

VIDEO IN

P6602P6603

DECK MD

MPEG/AMP

BOARD

SMPS

BOARD

TIMER

BOARD

KEY BOARD

VCR

3-3

ELECTRICAL ADJUSTMENT PROCEDURES

1. Servo Adjustment

1) PG Adjustment

• Adjustment And Specification

• Test Equipment a) OSCILLOSCOPE b) NTSC MODEL : NTSC SP TEST TAPE

MODE

PLAY

• Adjustment Procedure

a) Insert the SP Test Tape and play. b) Press the “O” key on the Remote controller and the “PLAY” key on the Front Panel the same time, the

unit then goes in to Tracking initial mode.

c) Trigger the mixed Combo Video Signal of CH2 to the CH1 H/SW(W373, W374), and then check the dis-

tance (time difference), which is from the selected A(B) Head point of the H/SW(W373, W374) signal to the starting point of the vertical synchronized signal, to 6.5H ± 0.5H (412µs, 1H=63µs). Note - Press FRONT CH UP KEY and FRONT PLAY KEY on Deck playback, and it goes in to ATR PRE-

SET. after the SP Test Tape is inserted.

• PG Adjustment Method

a-1) Playback the SP standard tape b-2) Press the “O” key on the Remote controller and the “PLAY” key on the Front Panel the same time,

Tracking initial mode. c-3) Repeat the above step(No.b-2), the unit will then finish the PG adjusting automatically. d-4) Stop the playback, the unit then exits PG adjusting mode after saving the PG data.

• CONNECTION

• WAVEFORM

V.Out

H/SW(W373, W374)

R/C TRK JIG KEY 6.5 ± 0.5H

MEASUREMENT POINT ADJUSTMENT POINT SPECIFICATION

V.Out

H/SW(W373, W374)

OSCILLOSCOPE

CH1 CH2

V.outH/SW

R/C KEY

(W373, W374)

H/SW

Composite

VIDEO

6.5H(412µs)

VCR PART

3-4

ELECTRICAL TROUBLESHOOTING GUIDE

1. Power(SMPS) CIRCUIT

NO 5.3VA.

Replace the F101.

(Use the same Fuse)

Is the F101 normal?

Is the TH101 normal?

Is the BD101 normal?

Replace the BD101.

Replace the TH101.

Is the D105 normal?

Check or Replace the D105.

Replace the D129.

Replace the IC106.

YES

Is Vcc(8.5~21V) supplied to IC104 Pin3?

Is the D129 normal?

Is there about 2.5V at the IC106 Vref?

Check the Main PCB

5.3VA/5.0V Line short?

(1) No 5.3VA (SYS/Hi-Fi/TUNER)

NO 12VA.

Check or Replace the D126.

Is the Vcc(13V) supplied to (+) terminal in D126?

Check or Replace the Motor Vcc.

YES

(2) No 12VA (TO CAP, DRUM MOTOR)

NO 5.0VA.

5.3VA Line Check.

Is 5.3VA put into the Q167 Emitter?

Is about 5V put into the Q167 Base?

Is the Q169 Base “H”?

Check the Power Control.

Check or Replace the Q169, R175, R176, R177.

YES

Check or Replace the Q167/Q169.

YES

(3) No 5.0V (SYS/Hi-Fi/TUNER)

3-5

NO 5V.

5.3VA Line Check.

Is 5.3VA put into the Q168 Emitter?

Is about 5V put into the Q168 Base?

Is the Q169 Base “H”?

Check the Power Control.

Check or Replace the Q169, R175, R176, R177.

YES

Check or Replace the Q168/Q169

(4) No 5V (TO DVD)

No 33V.

Check the Power Control.

Is Q163 Base “H”?

Check or Replace Q163, R168, R169.

YES

(5) No 33V (TUNER)

NO 8V.

Check or Replace the D126.

Is Vcc(13V) supplied to (+) terminal in D126?

Check or Replace IC161, C163.

Is Vcc(12V) supplied to IC160 Pin1?

Check or Replace the D163.

YES

(6) No 8V(TO DVD)

3-6

2. SYSTEM/KEY CIRCUIT

(1) AUTO STOP

(2) The unstable loading of a Cassette tape

Auto Stop

Does the SW30 waveform appear at the IC501 Pin18?

Do the T-UP Reel Pulses appear at the IC501 Pin80?

Is 12V applied to the

PMC01 Pin8?

Check the Drum Motor signal.

Does 5V appear at the RS501?

Check the Q160 Power Circuit.

Refer to “SMPS DRUM 12 Volt Trouble Shooting”.

Is 5V applied to the R531 ?

Refer to SMPS 5.3VA troubleshooting.

Check the IC501 Pins22, 23, 24, 25.

Do T/UP Reel Pulses appear at the point between R556 and R536?

Replace the T/UP Reel Sensor (RS501).

Check the CST SW and the peripheral circuitry.

Replace the IC501.

The unstable loading of a

Cassette tape

Does the “H” signal appear at the IC501 Pin58 during inserting the CST ?

Does the “L” signal appear at the IC501 Pin60 during inserting the CST?

Check the Deck Mechanism.

Caution :

Auto stop can occur because Grease or Oil has dried up

YES

NO NO

YES

YES YES

3-7

3. SERVO CIRCUIT

(1) Unstable Video in PB MODE

Unstable Video in PB Mode.

Does the Noise level of the screen change periodically?

Do the CTL pulses appear at the IC501 Pin97?

Is adjusting the height of the CTL Head accurate?

Readjust the height of the CTL Head.

Replace the IC501.

Refer to “When the Y signal doesn’t appear on the screen in PB Mode”.

Does the CFG waveform appear at the IC501 Pin87?

On tracking do the CTL pulses move?

Does the Video Envelope waveform appear at the IC501 Pin9?

Replace the IC501.

YES

(2) When the Drum Motor

(2) doesn’t run.

Do the DFG Pulses appear at the PMC01 Pin11?

Replace the Cap M.

Aren’t the foil patterns and the Components between IC501 Pin 90 and PMC01 Pin11 short?

Replace the IC501.

Refer to “(2) No 12VA of Power section”

Do the Drum PWM Pulses appear at the IC501 Pin76?

Aren’t the foil patterns and

the Components between IC501 Pin76 and PMC01 Pin12 short?

Do the DFG Pulses appear

at the IC501 Pin90?

Do the Drum PWM Pulses appear at the IC501 Pin76?

Aren’t the connecting patterns and the Components between IC501 Pin76 and PMC01 Pin12 short?

When the Drum Motor doesn’t run,

Does 12V appear at the PMC01 Pin8?

Does 2.8V appear at the PMC01 Pin12?

Check the connector (PMC01) and the Drum Motor Ass’y.

YES

3-8

Does the CFG signal appear at the PMC01 Pin1?

Does the PWM signal appear at the IC501 Pin77?

Is “DRUM CTL” 2.8V appear at the PMC01?

Check the PMC01 and the Capstan Motor Ass’y.

Does the Capstan PWM signal appear at the IC501 Pin77?

Aren’t the foil patterns and Components between IC501 Pin77 and PMC01 Pin9 short?

Does the CFG signal come into the IC501 Pin87?

Aren’t the foil patterns and Components between IC501 Pin77 and PMC01 Pin9 short?

2. SERVO CIRCUIT

(3) When the Capstan Motor doesn’t run,

YES

When the Capstan Motor doesn’t run,

Does 12VA appear at the PMC01?

YES

Replace the IC501.

YES

Refer to “SMPS(CAPSTAN/12Volt) Trouble Shooting”.

Aren’t the foil patterns and component between IC501 Pin87 and PMC01 Pin1 short?

Check the Capstan Motor Ass’y.

3-9

4. OSD CIRCUIT

(1) No OSD display.

(2) I

C BUS CHECK

KEY doesn’t working.

Is 5V applied to the IC501 Pin2, 3?

Does LED or FLD change when a function button is pressed?

No OSD or F.OSD display.

Is 5.3V applied to the IC501 Pin53?

Does oscillation occur at the IC501 Pins44, 45?

Replace the IC501.

The I2C waves don’t

come out.

Does Power appear at the Pull up impedence (R569, R507)?

Replace the IC501.

Refer to “SMPS 5.3VA Trouble Shooting”.

Replace the defective switches.

Refer to “SMPS 5.3VA Trouble Shooting”.

Check or Replace the pheripheral Circurity.(L511, R598, C596, C595)

Refer to “SMPS 5.3VA Trouble Shooting”.

YES

2. SERVO CIRCUIT

(4) KEY doesn’t working

3-10

5. Y/C CIRCUIT

(1) No Video in EE Mode,

No Video in EE Mode

Does the Video signal appear at the IC302 Pins1, 5?

Is there 5V at the IC302 Pin6?

Replace the IC302.

Does the Video signal appear at the IC301 Pins28, 30, 32?

Is REG 5.0V applied to the IC301Pins23, 44, 45, 52, 68, 77?

Does the Video signal appear at the IC301 Pin26?

Does the Video signal appear at the IC501 Pin52?

Does the Video signal appear at the IC602 Pin7?

Check the REG 5V Line. (Power Circuit)

Is I2C BUS signal applied to the IC301 Pins53, 54, 55?

Replace the IC301.

Check the path of the signal between the IC301 Pin 26 and IC501 Pins50, 52.

Is there 5V on the plus terminal of the C614?

Check the REG 5V Line. (Power Circuit)

Replace the IC602.

Check the System Circuit. (Refer to ‘SYSTEM I2C BUS CHECK Trouble Shooting’)

YES

Check DVD Video Input (IC602, Pin4), Tuner Video Input (TU701 Pin16), Line Video Input (JK601), respectively.

3-11

3. Y/C CIRCUIT

(2) When the Y(Luminance) signal doesn’t appear on the screen in PB Mode,

Is 5V applied to the IC301 Pins23, 44, 45, 52, 68, 77?

Is the Y/C Bus siganl applied to the IC301 Pins53, 54, 55?

Does the normal RF signal appear at the IC301 Pin 14?

Check the line of the REG 5V Line. (Power Circuit)

Check the System Circuit. (IC501 Pin18)

Check the V.H.S/W level.

Refer to ‘SYSTEM Y/C BUS CHECK Trouble Shooting’.

Is the V.H.S/W signal applied to the IC301 Pin57?

Does the Rectangular waveform(5V) appear at the IC301 Pin57(V.H.S/W)

Clean the Drum.

Check the C324.

Check the R328, R347, C322, C323.

Does the Y(Luminance) signal appear at the IC301 Pin20?

Is the Y(Luminance) Video waveform showed up at the IC301 Pin22?

Replace the IC301.

YES

3-12

3. Y/C CIRCUIT

(3) When the C(Color) signal doesn’t appear on the screen in PB Mode,

Is 5V applied to the IC301 Pins23, 44, 45, 52, 68, 77?

Does the fsc signal appear at the IC301 Pins41, 50?

Check the line of the REG 5V Line. (Power Circuit)

Replace the X301.

Check the C342, C341, R333.

Is normal the X301 (3.58MHZ) of oscillation Frequency?

Replace the IC301.

Does the Color signal appear at the IC301 Pin48?

Replace the IC301.

YES

3-13

3. Y/C CIRCUIT

(4) When the Video signal doesn’t appear on the screen in REC Mode,

YES

Check system part (V.H/SW)

Replace the IC301.

Check the drum

*OPTION Pins72, 73, 74(SP) Pins65, 66, 67(EP)

REC mode

Check the EE mode

Is EE mode normal?

Is color

normal?

YES YES

Is brightness normal?

Does signal appear at IC301 Pins41, 50?

Check X301 oscillation frequency.

YES

Is the brightness signal supplied to IC301 Pins18?

Is 5V supplied to IC301 Pins23, 44, 45, 68, 77?

Check the power of Pins23, 44, 45, 52, 68, 77.

Check the 5V power

Is Y/C Bus applied to IC301 Pins53, 54, 55?

Check the REG 5V power

Check system part

Do X301 and X-TAL oscillate?

Check X301.

Is V.H SW supplied to IC301 Pin57?

Does the FM signal appear at IC301 Pins73(SP)/ 66(EP)?

3-14

6. Tuner/IF CIRCUIT

(1) No Picture on the TV screen

No picture on the TV screen

Does the Video signal at the TU701 Pin16.

YES

Is +33V applied to TU701 Pin14?

YES

Is +5V applied to TU701 Pin3?

Does the video signal appear at IC302 Pin7.

Does the Video signal at the IC501 Pin 52.

YES

Does the Video signal at the IC602 Pin 7.

YES

Check the signal flow from IC602 Pin7 to JK601 Pin Video out.

YES

Check 33V line.

Check 5V line.

YES

Does the Clock signal appear at TU701 Pin9?

Check the lIC Clock Signal of µ-COM Pin71.

YES

Does the data signal appear at TU701 Pin10?

Replace Tuner.

Check the signal flow from IC501 Pin27.(Pin27 is ‘L’ state in Tuner Mode)

Check the signal from IC301 Pin26 to IC501 Pin50.

Check the signal from IC501 Pin52 to IC602 Pin1 and IC602 Pin2. (IC602 Pin2 is ‘L’ state in VHS mode)

Check the lIC Data Signal of µ-COM Pin72.

3-15

(2) No Sound

No Sound.

Check the Vcc of TU701 Pins3, 14.

YES

Check 5.2V, 33V Line.

Check the Tuner SiF signal at IC801 Pin57.

YES

Check the Audio of IC801 Pins78, 80.

YES

Check the Signal flow from IC801 Pins78, 80 to JK601 Audio out(L), (R)

YES

Check the Tuner SIF of TU701 Pin13.

1. Check the Vcc(5.3VA, 9V) of IC801 Pins3, 5, 36, 54.

2. Check the IIC Clock and Data at IC801 Pins37, 38.

3-16

Check power.

Check REC start “H” signal of µ-COM.

Check IC501 Pin 19.

(Audio Swich 30)

Check the Vcc of IC801. (Pins 3, 15, 32, 46)

Is Pin 30 of IC801 over

3.5V ?

Is the Head switching signal IC801 Pin 39 O.K?

Check the connection at P3D01 if good then Replace IC801.

Check Ports of µ-COM.

Check A.MUTE port of µ-COM (Pin High of IC501).

Replace IC801.

Hi-Fi Playback.

No sound

Check the Hi-Fi Selection Switch and the Tape quality.

Is the RF waveform at IC801 Pin 23 over 3V Vp-p?

Check the Contact point of Audio Output.

Do Audio signals appear at IC801 Pin 80(L-CH), 78 (R-CH)?

Is IC801 Pin 49(A.Mute) “High”?

Check IC801 Pin 37(Data), Pin 38(Clock).

YES

7. Hi-Fi Circuit

YES

3-17

Hi-Fi REC.

It is impossible to record and playback Hi-Fi Audio signal.

Check Vcc of IC801. (Pins 3, 15, 32, 46)

Check Power.

Check ports of µ-COM.

Check the Port of µ-COM.

Check Audio Input signal Line (9, 11, 12, 71, 73, 74), Tuner(57).

Replace IC801.

Check the Port of u-COM.

Check IC801 Pin 37(Data),Pin 38(CLOCK).

Is IC501 Pin 84(A.Mute) “High”?

YES

Are Audio signals present at IC801 Pins 78, 80?

Do FM Audio signals appear at IC801 Pin 26?

YES

Is IC801 Pin 17(REC “H”) “High”?

Check the Contact Points of Drum

Connector if good then Replace the Drum.

YES

3-18 3-19

BLOCK DIAGRAMS

1. POWER(SMPS) BLOCK DIAGRAM 1

BD101

LINE FILTER

BLOCK

( C101, C102,

L101, L102 )

V101

F101

BD101

C103

DRIVE & S/W BLOCK

QUASI-RESONANT BLOCK

( IC101, R114, R115, C123, C107,

BC101, D108, R101, D102, R102,

D103, R106, ZD102, Z101, C108,

R104, C109, C110)

DRIVE & S/W BLOCK SOFT-START BLOCK

( R107, R108, C121, R105,

C120, C119, ZD1103, D105,

R111, BC102 )

T101

32VA

PSW01

RECTIFER & SMOOTHING

BLOCK

( D122, C131, R131,

C132, C133, C135, L122 )

PWR SENSE

FEED-BACK

BLOCK

SNUBBER

BLOCK

( R110, C115,

D104, C117 )

IC102

IC103

T102

( R122, R121, C136,

R123, R124, R125,

F102

(D123, C130, ZD121, R127)

R126 )

RECTIFIER & SMOOTHING

BLOCK

RECTIFIER & SMOOTHING

BLOCK

( D124, C137, R128 )

RECTIFIER & SMOOTHING

BLOCK

( D125, R129, C138 )

RECTIFIER & SMOOTHING

BLOCK

( D126, C140, L122, C141 )

PWR SENSE

BLOCK

( R184, R185 )

PSV01

FD(+)

FD(-)

-29VA 33VA 13VA

3.8VA

5.3VA

RECTIFIER & SMOOTHING

BLOCK

( D127, C142, L123, C146 )

PW101

(BK)

(WH)

NOTES) Symbol denotes AC ground.

NOTES) Symbol denotes DC chassis ground.

C113C114

C122

RECTIFIER & SMOOTHING

BLOCK

( D129, C144, L124, C147 )

FEED-BACK

BLOCK

IC105

IC106

( R132, R133, C148,

R134, R135, R136,

R137 )

TOSHIBA

LH-C444M

3-20 3-21

2. POWER(SMPS) BLOCK DIAGRAM 2

33VT BLOCK

(Q163, R168,

R169, R170)

TO SYS

FD(+)

TO SYS

FD(-)

TO SYS

-29VA

3.3V BLOCK

(IC161, C164)

TO TU

33V

FD(+)

FD(-)

-29VA GND

33VA

GND

13VA

GND

3.8VA

3.8VA GND

5.3VA

5.3VA GND GND

PVS01

15 14 13 12 11 10

1 2 3 4 5 6 7 8

9 10 11 12

TO SYS

PVD01

5.3VA

5.0V 8V

GND (M)

GND (A)

3.3V 5V

GND

3.5V

A.GND D.GND

5.3VA

8V BLOCK

(IC160, D163,

C163, R161)

9V BLOCK

(Q162, R171, ZD163)

9 8 7 6 5 4 3 2

3.3V BLOCK

(IC163, C177)

3.5V BLOCK

(IC162, D165, C172)

5V BLOCK

(Q168, R178, R179,

R180, C169)

5.2V BLOCK

(Q167, C168, R175,

R176, R177)

TO TU/SYS/ Hi-Fi

5.2V

FROM µ-COM

PWR CTL 'H'

TO A VCP

REG 5V

(Q166, C166, C167,

R174, ZD161)

PWR CTL BLOCK

(Q169, C170, R181,

R182, R183)

TOSHIBA

LH-C444M

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