LG XBR-446 Service manual

1-1

SECTION 1

SUMMARY

CONTENTS

PRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRODUCTS ............. 1-2

SERVICING PRECAUTIONS .................................................................................................. 1-3

THE STEPS FOR CHANGE THE OPTION CODE ........................................................... 1-4

SPECIFICATIONS ...................................................................................................................... 1-5

1-2

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 LG 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 LG 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 modi- fications 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.

1-3

SERVICING PRECAUTIONS

CAUTION: Before servicing the VCR + DVD RECODER 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.

Remember Safety First:

General Servicing Precautions

1. Always unplug the VCR + DVD RECODER AC power cord

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

module, or any other assembly.

(2) Disconnecting 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 VCR + DVD

RECODER 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 VCR + DVD RECODER and

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

6. Always connect the test instrument ground lead to an

appropriate ground before connecting 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 include 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 grounded-tip soldering iron to solder or unsolder ES devices.

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

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

6. Do not remove a replacement ES device from its protective 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.)

1-4

THE STEPS FOR CHANGE THE OPTION CODE

Push Switch POWER ON/ OFF

at remocon or timer keyborad

Select DVD MODE at the set

use remocon or timer keyborad

Push REC+ PLAY

at timer keyboard

Use remocon and push ENTER

Use Direction Key at

remocon (LEFT/ RIGHT)

for select the position of option

Use Direction Key

at remocon (UP/ DOWN)

for change the option

After finish edit code of option

push ENTER at remocon

For finishing and intialized

the option code push REC+ FF at remocon

NAME HEX BINARY OPT1 F2 00000000 OPT2 55 00000000 OPT3 53 00000000 OPT4 FD 00000000 OPT5 07 00000000 OPT6 0C 00000000 OPT7 20 00000000 OPT8 00 00000000 Press “Enter” key to Save and Exit

DETECT NEW EEPROM (OPTION EDIT SCREEN)

1-5

SPECIFICATIONS

General

Power requirements AC 100V, 50/60 Hz Power consumption 35W Dimensions (approx.) 430 X 79 X 367 mm Mass (approx.) 5.5 kg Operating temperature 5 °C ~ 40 °C Standard Condition -20 °C ~ -60 °C Signal system NTSC

VDR PART

Read Disc Format DVD Disc : DVD Video Specification Book.

CD-DA Disc : RED Book. Write Disc Format DVD±R/DVD±R/W Disc : DVD±RW Recorder Specification Book Video System NTSC Data Multiplexing MPEG-2(ISO/IEC 13818-1) Data Decoding Standards MPEG-1, MPEG-2 Audio Compression Read : AC-3 : ATSC Standard for ATV MPEG-1, MPEG-2

Write : MPEG-1, Layer-2

VCR PART

Video Head System Double azimuth 4head helical scanning Tape Format Tape width 12.7mm(0.5 inch) Timer 24hours display type

OUTOUT

VIDEO OUTPUTS 1.0 V (p-p), 75 Ω negative sync,RCA jack x 1 S-VIDEO OUTPUT (Y)1.0 V (p-p), 75 Ω negative sync, Mini DIN 4-pin x 1

(Pb)/(Pr)0.7 V (p-p), 75 Ω Audio output (analog output) (-)6dBm, less than 1kΩ RCA jack x 2 Audio output (digital output) 0.5 V (p-p), 75 Ω, RCA jack x 1 Audio output (optical output) 5 V (p-p), 75 Ω, Optical connector x 1

2-1

SECTION 2

EXPLODED VIEWS

CONTENTS

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

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

2. Deck Mechanism (RL-02A)......................................................................................................2-3

3. Packing Accessory Section ....................................................................................................2-4

2-2

EXPLODED VIEWS

1. Cabinet and Main Frame Section

250

469

463

255

469

256

257

469

470

47A

463

300

260

276

284

283

285

287

286

469

280

288

289

274

457

278

457

470

457

263

266

265

320

261

452

261A

323

321

264

468

469

BCD

2-3

1001

A001

A000

A60

A003

1434

1025

1030

1432

1038

1028

1040

1432

1021

1432

1032

1033

1023

1011

1019

1020

1019

1009

1012

1013

1435

1014

1016

1015

1017

1018

1018A

1018B

1018C

1018E

1018D

1006

1045

1436

1024

1433

1022

1432

1031

1029

1027

1005

1026

1003

1002

1431

A004

A002

A51

1041

1043

1042

1044

1042

1434

2. Deck Mechanism Section (RL-02A)

2-4

3. Packing Accessory Section

BATTERY

808

BAG

804

PACKING

803

806

INSTRUCTION ASSEMBLY

CABLE(COAXIAL)

810

CABLE ASS'Y RF

801

REMOCON

900

BOX CARTON

802

PACKING

803

811

812

PLUG ASS'Y 1WAY

PLUG ASS'Y 2WAY

OPTIONAL PARTS

3-13-1

SECTION 3

ELECTRICAL

CONTENTS

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

VCR PART ELECTRICAL ADJUSTMENT

PROCEDURES

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

VCR ELECTRICAL TROUBLESHOOTING GUIDE

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

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

2. SYSTEM/KEY CIRCUIT ..........................................3-7

3. SERVO CIRCUIT.....................................................3-8

4. OSD CIRCUIT........................................................3-10

5. Y/C CIRCUIT..........................................................3-11

6. TUNER/IF CIRCUIT ...............................................3-15

7. Hi-Fi CIRCUIT........................................................3-17

BLOCK DIAGRAMS................................................3-20

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

2. TUNER/MTZ BLOCK DIAGRAM ...........................3-22

3. Y/C BLOCK DIAGRAM ..........................................3-24

4. NORMAL AUDIO BLOCK DIAGRAM ....................3-26

5. JACK BLOCK DIAGRAM.......................................3-28

6. Hi-Fi BLOCK DIAGRAM ........................................3-30

7. SYSTEM BLOCK DIAGRAM .................................3-32

CIRCUIT DIAGRAMS..............................................3-34

1. POWER(SMPS) CIRCUIT DIAGRAM....................3-34

2. TU/IF CIRCUIT DIAGRAM.....................................3-36

3. A/V CIRCUIT DIAGRAM........................................3-38

4. JACK CIRCUIT DIAGRAM.....................................3-40

5. Hi-Fi CIRCUIT DIAGRAM ......................................3-42

6. SYSTEM CIRCUIT DIAGRAM...............................3-44

7. TIMER CIRCUIT DIAGRAM...................................3-46

8. FRONT A/V, 1394 JACK CIRCUIT DIAGRAM.......3-48

• WAVEFORMS..........................................................3-50

• CIRCUIT VOLTAGE CHART....................................3-52

PRINTED CIRCUIT DIAGRAMS.........................3-54

1. VCR P.C.BOARD....................................................3-54

2. POWER P.C.BOARD ............................................3-56

3. TIMER P.C.BOARD ...............................................3-56

4. KEY P.C.BOARD ...................................................3-58

5. JACK P.C.BOARD .................................................3-59

VDR PART ELECTRICAL TROUBLESHOOTING

GUIDE & WAVEFORMS

.........................................3-60

1. POWER(SMPS) CIRCUIT .....................................3-60

2. NO COMPONENT VIDEO SIGNAL WHEN

PLAYING DISC ......................................................3-62

3. NO COMPOSIT / S-VIDEO SIGNAL WHEN

PLAYING DISC ......................................................3-63

4. NO TV, EXTERNAL INPUT VIDEO SIGNAL .........3-64

5. WHEN PLAYING DISC, NO AUDIO OUTPUT.......3-65

6. NO TUNER AUDIO OUTPUT................................3-65

7. NO OPTICAL / DIGITAL OUTPUT.........................3-65

8. NO EXTERNAL INPUT 1 AUDIO ..........................3-66

9. NO EXTERNAL INPUT 2 AUDIO ..........................3-66

BLOCK DIAGRAMS................................................3-67

1. VDR MAIN H/ W BLOCK DIAGRAM .....................3-67

2. POWER BLOCK DIAGRAM...................................3-68

3. AUDIO IN/ OUT BLOCK DIAGRAM ......................3-69

CPU & CONTROL REGISTER BLOCK DIAGRAM

...3-70

5. VIDEO IN/ OUT BLOCK DIAGRAM.......................3-71

6. DV 1394 IN/OUT BLOCK DIAGRAM.....................3-72

7. MEMORY CARD IN/ OUT BLOCK DIAGRAM ......3-73

CIRCUIT DIAGRAMS..............................................3-74

1. BGA 308P CIRCUIT DIAGRAM.............................3-74

2. DDR & B TO B CONNECTOR CIRCUIT

DIAGRAM ..............................................................3-76

3. POWER, FLASH, CONNECTOR CIRCUIT

DIAGRAM ..............................................................3-78

4. RST, CONTROL/STATUS_REG., ATAPI,

HOST_CPLD, LATCH CIRCUIT DIAGRAM...........3-80

5. VIDEO_IN, VIDEO_OUT CIRCUIT DIAGRAM ......3-82

6. DV1394, HDMI CIRCUIT DIAGRAM......................3-84

7. AUDIO IN/OUT CIRCUIT DIAGRAM.....................3-86

• WAVEFORMS..........................................................3-88

• CIRCUIT VOLTAGE CHART....................................3-90

PRINTED CIRCUIT DIAGRAMS.........................3-92

1. VCR P.C.BOARD(TOP VIEW)................................3-92

2. POWER P.C.BOARD (BOTTOM VIEW).................3-94

RL-02A LOADER PART.................................3-98~160

OVERALL WIRING DIAGRAM

3-2

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) Connect the CH1 of the oscilloscope to the H/SW and CH2 to the “VCR VIDEO” TP for the VCR. c) Trigger the mixed Combo Video Signal of CH2 to the CH1 H/SW, and then check the distance (time dif-

ference), which is from the selected A(B) Head point of the H/SW(W5D1, W5D2) signal to the starting point of the vertical synchronized signal, to 6.5H ± 0.5H (412µs, 1H=63.5µs).

• PG Adjustment Method

a-1) Playback the SP standard tape b-2) Press the “ENTER” key on the Remote controller and the “REC” key on the Front Panel at the same

time, then it goes into Tracking initial mode. < Digitron[ - - ] > c-3) Repeat the above step(No.b-2), then it finishes the PG adjusting automatically. < Digitron[ PG ] > d-4) Stop the playback, then it goes out of PG adjusting mode after mony the PG data.

• CONNECTION

• WAVEFORM

V.Out

H/SW(W5D1, W5D2)

R/C TRK JIG KEY 6.5 ± 0.5H

MEASUREMENT POINT ADJUSTMENT POINT SPECIFICATION

H/SW

(W5D1, W5D2)

(VCR

VIDEO)

(CH2)

(CH1)

OSCILLOSCOPE

CH1 CH2

R/C KEY

H/SW

(W5D1, W5D2)

VCR BOARDVDR BOARD

"VCR VIDEO" TP

VCR PART

H/SW

Composite

VIDEO

6.5H(412µs)

3-4

VCR ELECTRICAL TROUBLESHOOTING GUIDE

1. Power(SMPS) CIRCUIT

NO 5.3VA.

Replace the F101 (Use the same Fuse)

Is the F101 normal?

Is the TH01 Normal?

Is the BD101 Normal?

Replace the BD101

Replace the TH01

Is the D102 normal?

Check or Replace the D102

Replace the D121

Replace the IC103

Replace the D126

Replace the D129

Replace the D130

Replace the D127

Replace the D128

YES

Is the Vcc (11V - 18V) supplied to IC101 Pin2?

Is the D121 normal?

Is there about 2.5V at the IC103 Pin1?

Is the D126 normal?

Is the D129 normal?

Is the D130 normal?

Is the D127 normal?

Is the D128 normal?

YES

Power Line of Main PCB(VCR) is short

VCR ELECTRICAL TROUBLESHOOTING GUIDE

3-5

No 12VA

Check or Replace the D126

Is the Vcc(13V) supplied to C130?

Check or Replace the Cap / Drum

Is the D132 Normal?

Replace the D132

YES

(To Cap, Drum Motor )

No REG 12V

Check or Replace the D126

Check the ‘PWR CTL “H”’signal from µ-com

Check the 33V Line

Replace the Q126

Is the Vcc(13V) supplied to Q126Collector?

Is the Vcc(33V) supplied to Q126 Base?

Is the Q126 Nomal?

Check or Replace the D126

YES

NO VFD

Check or Replace the R107

Is the R107 Normal?

Is the D128 Normal?

Check or Replace the D128

Check or Replace the ZD151

YES

Is the ZD151 Normal?

Check or Replace the D127

YES

No 33V

Check or Replace the D130

Is the Vcc(33V) supplied to Q123 Emittor?

Is the Q123 Base ‘H’?

Check the ‘PWR CTL “H”’signal from µ-com

YES

Check or Replace the Q123

YES

3-6

VCR ELECTRICAL TROUBLESHOOTING GUIDE

No 28V (HSR)

Check or Replace the D129

Is the Vcc(30V) supplied to Q120 Collector?

Is the Vcc(33V) supplied to Q121 Collector?

Is the Vcc(30V) supplied to Q120 Base?

Check or Replace the ZD153

Check the ‘HSR “H” signal from µ-com

Check or Replace the Q121/Q122 & 33V line

YES

Check or Replace the Q120

YES

3-7

2. SYSTEM/KEY CIRCUIT

(1) AUTO STOP

(2) The unstable loading of a Cassette tape

Auto Stop

Does the SW30 waveform appear at IC501 Pin18?

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

Is 12V applied to PMC01 Pin8?

Check the Drum Motor signal.

Does 5V appear at the RS501?

Check the Q124 Power Circuit.

Refer to “SMPS DRUM 12 Volt Trouble Shooting”.

Is 5V applied to R531 ?

Refer to SMPS 5.3VA troubleshooting.

Check 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 IC501 Pin60 while inserting the CST ?

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

Check the Deck Mechanism.

Note :

Auto stop can occur because Grease or Oil has dried up

YES

NO NO

YES

YES YES

VCR ELECTRICAL TROUBLESHOOTING GUIDE

3-8

3. SERVO CIRCUIT

(1) Unstable Video in PB MODE

Does the Noise level of the screen change periodically?

Do the CTL pulses appear at IC501 Pin97?

Is the height adjustment of

the CTL Head accurate?

Check Deck Motor.

Readjust the height of the CTL Head.

Replace IC501.

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

Confirm the CFG waveform at IC501 Pin87?

On tracking, do the CTL pulses move?

Does the Video Envelope waveform appear at IC501 Pin9?

Replace IC501.

YES

NO NO

(2) When the Drum Motor

(2) doesn’t run.

Do the DFG Pulses appear at PMC01 Pin11?

Replace the Cap M.

Are the foil patterns and the Components between IC501 Pin 90 and PMC01 Pin11 shorted?

Replace IC501.

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

Do the Drum PWM Pulses appear at IC501 Pin76?

Are the foil patterns and the Components between IC501 Pin76 and PMC01 Pin12 shorted?

Do the DFG Pulses appear at IC501 Pin90?

Do the Drum PWM Pulses appear at IC501 Pin76?

Are the connecting patterns and the Components between IC501 Pin76 and PMC01 Pin12 shorted?

When the Drum Motor

doesn’t run,

Does 12V appear at PMC01 Pin8?

Does 2.8V appear at PMC01 Pin12?

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

YES

VCR ELECTRICAL TROUBLESHOOTING GUIDE

3-9

Does the CFG signal appear at PMC01 Pin1?

Does the PWM signal appear at IC501 Pin77?

Does 2.8V appear at PMC01?

Check the PMC01 and the Capstan Motor Ass’y.

Does the Capstan PWM signal appear at IC501 Pin77?

Are the foil patterns and Components between IC501 Pin77 and PMC01 Pin9 shorted?

Does the CFG signal come into IC501 Pin87?

Are the foil patterns and Components between IC501 Pin77 and PMC01 Pin9 shorted?

2. SERVO CIRCUIT

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

YES

When the Capstan Motor doesn’t run,

Does 12VA appear at PMC01?

YES

Replace IC501.

YES

Refer to “SMPS(CAPSTAN/12Volt)

Trouble Shooting”.

Are the foil patterns and component between IC501 Pin87 and PMC01 Pin1 shorted?

Check the Capstan Motor Ass’y.

VCR ELECTRICAL TROUBLESHOOTING GUIDE

3-10

4. OSD CIRCUIT

(1) I2C BUS CHECK

Keys do not work

Is 5V applied to IC501 Pin78?

Does FLD change when a function button is pressed?

No I2C bus communication

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

Replace IC501.

Refer to “SMPS 5.3VA

Trouble Shooting”.

Replace the defective switches.

Refer to “SMPS 5.3VA Trouble Shooting”.

YES

2. SERVO CIRCUIT

(4) Keys do not work

VCR ELECTRICAL TROUBLESHOOTING GUIDE

3-11

5.Y/C CIRCUIT

(1) No Video in EE Mode,

No Video in EE Mode

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

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

Does the Video signal appear at IC301 Pin26?

Does the Video signal appear at PMD02 Pin7?

Does the Video signal appear at the PMD02 Pin5?

Does the Video signal appear at the JK602 Video Out Jack?

Check the REG 5V Line. (Power Circuit)

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

Replace IC301.

Is there REG12 on the plus terminal of C653?

Check the REG 12V Line. (Power Circuit)

Check the Q605 (Video Buffer)

Check the VDR Module

Check the IC601 and Video Out Line

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

YES

Check the REG 5V Line. (Power Circuit)

Check VDR Video Input (PMD02 Pin 5), Tuner Video Input (TU701 Pin24), Line Video Input (IC602 Pins 1, 3, 5, 7), respectively.

VCR ELECTRICAL TROUBLESHOOTING GUIDE

3-12

3.Y/C CIRCUIT

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

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

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

Does the normal RF signal appear at IC301 Pin14?

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 IC301 Pin57?

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

Clean the Drum.

Check C324.

Check R328, C322, C323.

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

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

Replace IC301.

YES

VCR ELECTRICAL TROUBLESHOOTING GUIDE

3-13

3.Y/C CIRCUIT

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

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

Does the Color signal appear at IC301 Pins41, 50?

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

Replace X301.

Check C342, C341, R333.

Is X301 (3.58MHz) normal?

Replace IC301.

Does the Color signal appear at IC301 Pin48?

Replace IC301.

YES

VCR ELECTRICAL TROUBLESHOOTING GUIDE

3-14

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*?

VCR ELECTRICAL TROUBLESHOOTING GUIDE

3-15

6. Tuner/IF CIRCUIT

(1) No Picture on the TV screen

No picture on the TV screen

Does the Video signal appear at TU701 Pin16.

YES YES

Is +33V applied to TU701 Pin14?

YES

Is +5V applied to TU701 Pin3?

Does the video signal appear at IC302 Pin32.

YES

Does the Video signal appear at IC601 Pin 4.

Check the signal flow from IC601 Pin23 to JK601 Pin Video out.

YES

Check 33V line.

Check 5V line.

YES

Does the Clock signal appear at TU701 Pin9?

Check the l2C Clock Signal of µ-COM Pin71.

YES

Does the data signal appear at TU701 Pin10?

Replace Tuner.

Check the signal flow from IC501 Pin26.

Check the signal from IC301 Pin26 to IC601 Pin4

Check the l2C Data Signal of µ-COM Pin72.

VCR ELECTRICAL TROUBLESHOOTING GUIDE

3-16

VCR ELECTRICAL TROUBLESHOOTING GUIDE

(B) No Sound

No Sound.

Check the Vcc of IC801 Pins15, 32, 36,

46.

YES

Check 5.2V Line.

Check the Tuner SiF signal at IC801 Pin57.

YES

Check the oscillator of IC801 Pin51.

YES

Check the Audio of IC801 Pins78, 80.

Check the Tuner SIF of TU701 Pin22.

Replace X301

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

3-17

VCR ELECTRICAL TROUBLESHOOTING GUIDE

7. Hi-Fi CIRCUIT

(1) No Sound(EE Mode)

YES

No Sound.

Check the DVD Audio of IC801 Pins12, 74.

Check the AV1 Audio of IC801 Pins11,73.

Check the AV2 Audio of IC801 Pins9, 71.

Check the Vcc of IC801 Pins3, 54.

YES

Check the IIC Clock and DATA at IC801 Pins37, 38.

YES

Check the Audio of IC801 Pins78, 80.

YES

Check the JK601.

Check the VDR MODULE. (PMD02 Pins23, 25).

Check the RCA Jack. (JK601 Scart1 Audio in L, R).

Check the VDR MODULE. (PMD02 Pins27, 29).

Check the Power 9V.

YES

Check the IC501 Pins71, 72.

Replace IC801.

3-18

VCR ELECTRICAL TROUBLESHOOTING GUIDE

3.Y/C CIRCUIT

(2) Hi-Fi Playback

YES

PB mode

No Sound.

Check the Vcc of IC801 (Pins3, 15, 32, 36, 46, 54)

Check the Hi-Fi Selection switch. (IC801 Pin39) and the Tape quality.

Is the RF Envelope at IC801 Pin23 over 2Vp-p?

YES

Check IC801 Pin37(Data), Pin38(Clock)

YES

Do Audio Signals appear at IC801 Pin80(L-CH), 78(R-CH)?

YES

Do Audio Signals appear at JK601?

Check Power 5.2V, 9V.

Check IC501 Pin19 (A.H/SW)

Check the parts of µ-COM (IC501 Pins71, 72)

Check the Connection at P3D01 Pins7, 9.

Check the Jack(JK601)

3-19

(3)

Hi-Fi REC.

It can’t be recorded Hi-Fi Audio signal.

Check Vcc of IC801.

(Pins3, 15, 32, 36, 46, 54)

YES

Check IC801 Pin37(Data), Pin38(CLOCK).

YES

Do Audio signals appear at IC801 Pins78, 80?

YES

Do FM Audio signals appear at IC801 Pin27?

YES

Check the Contact Point of Drum Connector if good then Replace the Drum.

YES

Check Power 5V, 9V.

Check ports of µ-COM. (IC501 pins 71, 72)

Check Audio input signal of IC801 Pins11, 73(AV1), 12, 74(VDR.A.), 9, 71(AV2).

Replace IC801.

FUSE (F101)

NOISE FILTER

BLOCK (C101,L102, L101, C102)

SNUBBER

BLOCK

(D103,C115,C116

,R112,R115)

DRIVE & S/W BLOCK

(IC104, D104, R113,

C117,C114)

BD101

TH01

Y-CAP C110

Y-CAP C111

BR BL

(BK)(WH)

2.5V

3.3V

TO VDR

(P102)

C103

12V

5.0V

TO LOADER

(P103)

FD( +)

FD(-)

-28VA

TO VCR

(P101)

5.3VA

5.0V

Cap Vcc

12VA( DRUM)

33V

REG 12V

PWR CTL 'H'

HSR 'H'

DVD PWR CTL

5.0V

SNUBBER

BLOCK (D101,C105 C106,R103)

DRIVE & S/W BLOCK

(IC101, D102, R105,

C108,C112)

T101

T102

PHOTO COUPLER

(IC102)

ERROR AMP

(IC103)

FEED-BACK

BLOCK R121,R122, C121,R123.

R124.R125

R126)

RECTIFIER &

SMOOTING BLOCK

(D128,C133,R130)

RECTIFIER &

SMOOTING BLOCK

(D127,C131,L125,C132)

RECTIFIER &

SMOOTING BLOCK

(D125,C139,L127,C140)

RECTIFIER &

SMOOTING BLOCK

(D124,C129)

RECTIFIER &

SMOOTING BLOCK

(D123,C126,L124,C127)

RECTIFIER &

SMOOTING BLOCK

(D122,C123,L123,C125)

PHOTO COUPLER

(IC105)

ERROR AMP

(IC106)

FEED-BACK

BLOCK R131,R132, C141,R133.

R161.R162

R163)

12V REG & S/W Block

(IC157,R156,C155)

-12V 12V

1.8V

8.7V

TO FAN

(P103)

RECTIFIER &

SMOOTING BLOCK

(D129,C128,R147)

RECTIFIER &

SMOOTING BLOCK

(D130,C137,R146)

5.0V REG & S/W Block (IC151,R151,C151)

1.8V REG & S/W Block (IC160,R159,C152)

3.3V REG & S/W Block (IC154,R154,C154)

RECTIFIER &

SMOOTING BLOCK

(D126,C136,L122,C130)

RECTIFIER &

SMOOTING BLOCK

(D121,C122,L121,C124)

HSR S/W Block

(Q120,ZD153,C135,

R144,R145,D155,C157)

12V REG & S/W Block

(Q126,R150,ZD152,

C156,C153)

5.0V S/W Block

(Q124,R140,R135,R136

D134,C134)

33V S/W Block

(Q123,R143,R134)

HSR CTL Block

(Q121,Q122,R141)

PWR CTL Block

(Q125,R137,R138)

5 6 7 8

6 7 8

LGXBR446 (LGEUS)

3-20 3-21

BLOCK DIAGRAMS

1. POWER(SMPS) BLOCK DIAGRAM

A.IN

CH S/W

REG 5V

CONTROL

V.IN

RF AGC

ENABLE

CLOCK

DATA

AFT

A.OUT

SIF

TU 30V

V.OUT

999 GND

100AFT

731TU.V.OUT

875 MOD A.IN

61 MOD CTL

106 5V

26 VCR 'H'

671 MOD VEDIO

71 IIC CLK

72 IIC DATA

781 SIF OUT

LGXBR446 (LGEUS)

45833V

3-22 3-23

2. TUNER/MTZ BLOCK DIAGRAM

+ 114 hidden pages