SHARP VT-3418X, VT-5118X Service Manual

SHARP CORPORATION

1

DEPT.

2148

SERVICE MANUAL

TV/VCR COMBINATION

Chassis No. VP-

In the interests of user-safety (Required by safety regulations in some countries ) the set should be restored to its original condition and only parts identical to those specified should be used.

18X

MODELS

18X

FEATURE

n Full Auto Search Tuning System n

On Screen Digital Channel/Sound Level/ Tuning Display, Control (Contrast, Brightness, Tint, P-Tone) Symbol and Level

Blue Back Off Timer

n

40 Key, Wireless Remote Control Unit

n Channel Skip

Dew Warning Indicator

(Digital Program Search System)

.

SPECIFICATIONS

l

IMPORTANT SERVICE NOTES

l

LOCATION OF USER’S CONTROL

.

DISASSEMBLY AND REASSEMBLY

. ADJUSTMENT OF THE

TV ELECTRICAL CIRCUITRY

.

FUNCTION OF MAJOR MECHANICAL PARTS

. ADJUSTMENT, REPLACEMENTAND

ASSEMBLY OF MECHANICAL UNITS

. ADJUSTMENT OF THE

VCR ELECTRICAL CIRCUITRY

. TROUBLESHOOTING

........................

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.........

........

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.........

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High Speed Video Search System

l

PAUSECAM: 7 times

l

Quick Start Playback with Full Loading System

n

Still/Slow Function with Noiseless Frame Still

n n n

5

Digital Automatic Tracking Control Automatic Playback Function

(Automatic Head Cleaning System)

15 times

CONTENTS

Page Page

l

2 3

4 7

8

14

..

16

41 47

OVERALL SCHEMATIC DIAGRAM

l

CHASSIS LAYOUT OF TV SECTION

l

BLOCK DIAGRAM OF TV SECTION

.

DESCRIPTION OF TV SECTION

SCHEMATIC DIAGRAM

.

CHASSIS LAYOUT OF VCR SECTION

.

BLOCK DIAGRAM OF VCR SECTION

. DESCRIPTION OF VCR SECTION

SCHEMATIC DIAGRAM . PRINTED WIRING BOARD ASSEMBLIES . . .

REPLACEMENT PARTS LIST

.

PACKING OFTHESET

.................

........

.......

.............

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.....

......

.....

65 69 73

82 99

101

111 119 129 167

WARNING

The chassis in this receiver is partially hot. Use an isolation transformer between the line cord plug and power receptacle, when servicing this chassis. To prevent electric shock, do not remove cover. No user qualified service personnel.

serviceable parts inside. Refer servicing to

SHARP CORPORATION

n

OUTLINE OF THE PRODUCT

Power Source:

Power Consumption:

Receiving Broadcast Standard:

Receiving Channel:

Receiving System:

Antenna Input Impedance:

Video Signal:

Audio Signal:

Temperature:

mentions

Weight (Approx.):

Cabinet Material:

Accessories:

n

TV SECTION

Viewing Area:

Picture Power:

Speaker Output:

Picture Tube:

n

VCR SECTION

SPECIFICATIONS

PAL System B/G, I, D/K, M

VHF;

UHF; Sound;

VHF/UHF; Input; output;

Input;

output; Operation;

Plastic

Operation Manual Infrared Remote Control Unit Dry Batteries, Type AA Guarantee Card

Heater;

Focus;

V AC,

w W

PAL

ohm Unbalanced (DIN)

1

8 d b

W at Max.

High

Hz

MHz

mm

kg kg

cm Diagonal Measurement

Vp-p ohm (RCA)

75 ohm (RCA)

ohm (RCA)

to

x

cm Diagonal Measurement

at

cm Round Dynamic x 2 cm Round Dynamic x 2

mm

2

Beam Current

x

U-S (Tint Tube)

(TintTube)

mA

mm

Outline:

Format:

Video Recording System :

Luminance: FM Recording

Chrominance: Low Frequency Converted Direct Recording

Video Signal System: PAUSECAM/NTSC MHz

Cassette Tape:

Tape Width:

Tape Speed:

Recording/Playback Time:

Note: The antenna must correspond to the new standard DIN 45325

antenna with

ohm connector.

Video System

Rotary Slant Azimuth 2-Head Helical Scan System

Type Video Cassette Tape mm

PAL;

Standard

mm/s

Max. Max.

Max.

Video Cassette Recorder

mm/s

11.68 mm/s

(with

PAL only)

only)

only),

mm/s

for combined UHF

IMPORTANT SERVICE NOTES

Maintenance and repair of this receiver should be done by qualified service personnel only.

SERVICING OF HIGH VOLTAGE SYSTEM AND

PICTURE TUBE

When servicing the high voltage system,

connecting a probe) between picture tube

k ohm Resistor in series with an insulated wire (such as a test

and

remove static charge from it by

anode lead. (AC line cord should

be disconnected from AC outlet.)

Picture tube in this receiver employs integral implosion protection. Replace with tube of the same type number for continued safety. Do not lift picture tube by the neck.

Handle the picture tube only when wearing shatterproof goggles and after discharging

the high voltage completely.

X-RAY

This receiver is designed so that any X-Ray radiation is kept to an absolute

minimum. Since certain malfunctions or servicing may produce potentially hazardous radiation with prolonged exposure at close range, the following precautions should be observed:

If there is a possibility that the high voltage fluctuates as a result of the repairs, never

forget to check for such high voltage after the work.

DO not substitute a picture tube with unauthorized types and/or brands excess X-ray radiation.

When repairing the circuit, be sure not toincrease the high voltage to more than When repairing the circuit, be sure not to increase the high voltage to more than

To keep the set in a normal operation, be sure to make it function on

been factory

To keep the set in a normal operation,

factory -Adjusted to the above-mentioned high voltage.

+

(at beam 0

-Adjusted to the above-mentioned high voltage.

(at beam

for the set.

(at beam

in the case of the set. The set has

be sure to make it function on

in the case of the set. The set has been

BEFORE RETURNING THE RECEIVER

Before returning the receiver to the user, perform the following safety checks.

Inspect all lead dress to make certain that leads are not pinched or that hardware is not

lodged between the chassis and other metal parts in the receiver.

Inspect all protective devices such as non-metallic control knobs, insulating fishpapers,

cabinet backs, adjustment and compartment covers or shields, isolation resistorcapacity networks, mechanical insulators etc.

LOCATION OF USER’S CONTROL

STOP/EJECT BUlTON

PLAY BlJlTON

(Forward video search)

CONTROL PANEL

INSIDE THE COVER

POWER BUTTON

AUDIO INPUT JACK

I

VIDEO AUDIO

VOLUME UP/DOWN

I

CHANNEL UP/DOWN

r

video search)

I

SENSOR AREA FOR REMOTE CONTROL

q

MAIN POWER SWITCH

ANTENNA IN TERMINAL AUDIO OUT TERMINAL

OUT TERMINAL

I

. . .

POWER CORD

I)

MAIN POWER SWITCH

4

.

CORD

ANTENNA IN TERMINAL AUDIO OUT TERMINAL

VIDEO OUT TERMINAL

Remote Control Battery Installation

The remote control lets you operate this product at a distance. Just aim the front of the remote control at the photoreceptor window situated on the front panel and press the appropriate buttons.

Inserting the Batteries

The remote control operates on two AA)

volt batteries (included). If the remote control does not operate or fails to function normally due to weak batteries, new batteries can be purchased at

electronics or camera stores.

(UM/SUM-3,

Battery

cover

Location

POWER ON/OFF button EJECT/LOAD button

CHANNEL SELECT

buttons

DISPLAY button

button

of Controls

buttons

button

Open the battery cover. (Remove any old batteries that may be in the remote control.)

Insert new batteries and match their polarities ( + and ment.

Replace the cover.

with the markings inside the compart-

SHARP

VIDEO

I

MUTE button

CHILD-LOCK button

CHANNEL UP/DOWN&&tons

VOLUME ADJUSTMENT

buttons SLOW PLAYBACK button COUNTER RESET button

STOP button

(TRACKING buttons)

button

Video Search button

TIMER ON/OFF button CONFIRMING TIMER

PROGRAMME button

PAUSE/STILL button

Video Search button

PLAY button

+ buttons PROGRAMME button

MENU button

SET button

5

8X

n

TV SECTION

DISASSEMBLY AND REASSEMBLY

18X: Remove the nine screws off the rear cover.

Disconnect the F and G connectors from the main Remove the screws off the video unit and take out the unit. Remove the two screws from the main

Remove the eight screws off the rear cover.

and separate the

from the video unit

6

n

CONNECTIONS FOR SERVICING

Use the following extension cables in servicing the VCR unit taken out of the set.

Extension cables:

l

Connecting the extension cables

Between

Part codes

(TV unit) and

Connect the cable

jack):

between the

plug and the

socket.

Between AL (TV unit) and LA (LED unit):

Connect the cable

between the AL plug and the AL socket.

Extension cable: QCNW-3780CEZZ

Extension

cable: QCNW-3778CEZZ

Remove the CRT

the main

upright.

Reconnect the CRT

power switch remote control

VT-51 18X

Only for

Put the main

coil connector

and the VCR unit together as shown below. Keep the front

speakers and

and front power switch remote control

coil connector G off position.

Place

(Only for VT-341 8X)

Power

,

‘LINE FILTER PWB

PWB

DA

8X

I I

ADJUSTMENT

TV ELECTRICAL CIRCUITRY

ADJUSTMENT

I

Adjusting Conditions

CRT Cut-off Adjustment

Adjusting Point Cl

Cl

Note: Prior to this adjustment, warm up the unit with the beam current of more than

Receive “MONOSCOPE PATTERN” signal with

pattern generator.

Set Red bias control at

Set Green bias control at Set Blue bias control at Set Green drive control at CENTER position. Set Blue drive control at CENTER position.

Set the control at the “NORMAL” position that

Contrast is MAX Brightness is CENTER

Set the Screen control at Turn on

line position.

Connect the oscilloscope to

Red Bias control

Green Bias control

Blue Bias control

Green Drive control Blue Drive control

keys.

for more than

(Service switch) at the horizontal

minutes.

(O/l

using control, “A” and

position.

(O/l

position.

is CENTER

position.

(Red Cathode).

an

Adjusting Procedures

Adjust the Sub-Brightness control

the blanking pulse on oscilloscope is

Slowly turn the Screen control clockwise and stop

I

it where the horizontal raster appears slightly, in one of the three

Carefully adjust the Bias controls of the other two

untii the horizontal raster becomes white.

Turn the Screen control counterclockwise until

the horizontal raster disappears, and stop it.

so that

Sub-Contrast Adjustment

Adjusting Point

Sub-Contrast control

Note: Prior to this adjustment, warm up the unit with the beam current of more than

Receive “MONOSCOPE PATTERN” signal with

pattern generator.

Set the Contrast and Brightness controls at MAX

position.

Connect DC

(Full scale: 3

for more than 30 minutes.

to

and

8

Adjust Sub-Contrast control so that the beam

current becomes

I

mA

1

mA

ADJUSTMENT (Continued)

White Balance and Back Ground Adjustment

Adjusting Point

Green Drive control

Cl

Blue Drive control

Sub-Contrast control

Vote:

to this adjustment, warm up the unit with the

current of more than

for more than 30 minutes.

(VT-3418X) I

I. Receive “MONOSCOPE PATTERN” signal with

pattern generator.

Set the Contrast and Brightness controls at MAX

position.

Connect beam ammeter to

and

(Full scale: 3 mA)

Sub-Tint Adjustment

Adjusting Point

Feed

with Connect oscilloscope to Set the Tint control at the CENTER

Set Service switch

to cut off the Y-signal.

Sub-Tint control

COLOUR BAR” signal to video in jack

bar generator at the

mode.

position.

at the Video Cut position

Adjust the Sub-Contrast control so that the beam

current becomes

mA

1

mA

Adjust the Green Drive control and Blue Drive

control so that the colour temperature is at

l

High beam:

mA

mA(VT-5118X)

Adjust the Contrast control and Brightness

control so that the beam current is

at

and check that the

If the temperature is not at

temperature is

go back to “CRT CUT-OFF ADJUSTMENT” and repeat the adjustment.

Y = 0.292)

Adjust

control key to obtain the output of

Adjust Sub-Tint control

so that the output

waveform is as shown in figure below.

Return

Same

to CENTER (normal position).

level

Bell Filter Adjustment

Adjusting Point

Receive

bar generator.

Connect oscilloscope to TP1801 with the

following settings.

l

Range:

l

Sweep Time:

l

Probe:

Bell Filter

COLOUR BAR” signal with colour

div. AC

div.

l/l 0

1

or more)

B-Y

.

W Y

Adjust the Bell Filter

output and blue amplitude.

R

9

R B

so that the red

output will have the same

Same amplitude

ADJUSTMENT (Continued)

Adjusting Conditions

PAL

Adjusting Point

Cl

Note: Before this adjustment, the

adjustment must have been completed.

Receive “PAL COLOUR BAR” signal with pattern

generator.

Connect the following resistance matrix to pins 3

and 4 of the connector oscilloscope is connected.

Set the Service switch

position to cut off the Y-signal.

Adjustment

1 H Delay Amp. control 1 H Delay Phase control

to which an

To oscilloscope

Resistance Matrix

at the Video Cut

I

Adjust the

waveform of

vp-p.

Adjust

waveform shown in Fig. a is corrected to that shown in Fig.

Return

Adjusting Procedures

control key so that the output

difference signal becomes

and

to CENTER (normal position).

W

G Mg R B

so that the output

1

Figure a. Waveform before the adjustment

r

Adjusting Point

bar generator.

Connect oscilloscope to

following settings.

l

Sweep Time:

Killer Adjustment

COLOUR BAR” signal with

DC

(Adjust vertical position proper

div.

control

with the

Figure

Adjust

Waveform after the adjustment

to obtain maximum DC voltage at

ADJUSTMENT (Continued)

Adjusting Conditions Adjusting Procedures

R -Y/B

Adjusting Point

Receive “SECAM COLOUR BAR” signal with colour

bar generator.

Connect the oscilloscope (with two

on the CRT Socket Unit of the set.

l

Sweep Time:

Set service switch

to cut-off the Y-signal.

Set both the Contrast and Brightness controls to

their maximum postions.

Discriminator Adjustment

R Discriminator B

Y Discriminator

to

and the

DC

div.

at the Video Cut position

both located

Adjust

output level with will be the same as that with

of saturation. (A

* Connect capacitor (0.001

Set service switch

thus to prevent noise interference.

and

control set at minimum

to the canter position.

so that DC

control set at

to

and

Same

B

DC

DC output level

DEFLECTION LOOP ADJUSTMENT

Adjusting Conditions

Focus Adjustment

Adjusting Point

Receive “MONOSCOPE PATTERN” signal.

2 Set the Brightness and Contrast controls at

NORMAL position.

Horizontal Center Adjustment

Adjusting Point

RI

Note: This adjustment should be performed after

the purity and convergence adjustments.

Receive “MONOSCOPE PATTERN” signal.

Adjusting Procedures

l

During the adjustment, keep the unit facing the east.

Adjust Focus control (a part of

focus at the central area of CRT.

l

During the adjustment, keep the unit facing the east.

Adjust

picture is at the position which gives the relation

so that the horizontal center of

A-

l

to have best

Adjust point

4

Vertical Linearity Adjustment

Adjusting Point

Vertical Linearity control

Receive “MONOSCOPE PATTERN” signal.

Vertical Size Adjustment

Adjusting Point

Vertical Size control

Receive “MONOSCOPE PATTERN” signal. Set the Brightness and Contrast controls at MAX

position.

I

l

During the adjustment, keep the unit facing the east.

Adjust

picture is at best point.

l

During the adjustment, keep the unit facing the east.

Adjust

the same size as horizontal size. . V-SIZE

so that the vertical linearity of

so that the vertical size of picture is at

DEFLECTION LOOP ADJUSTMENT (Continued)

Adjusting Conditions

Vertical Centering Adjustment

Vertical Center Adjust switch

This adjustment should be performed after

the purity and convergence adjustments.

“MONOSCOPE PATTERN” signal.

ADJUSTMENT OF THE IF CIRCUIT

Adjustment of the RF

Test point

Adjusting point

I

(Video Output)

control)

Adjusting Procedures

l

During

Adjust

so that the picture’s vertical center is

Adjustment of the AFT

Measuring instrument Signal generator

Mode

Input signal

Test point

I

Adjusting point

keep the unit facing the east.

Oscilloscope

I

frequency

dBp)

I

(Video Output)

(AFT coil)

Receive the

strength:

bar signal (input field

Observe the video output terminal waveform

on the oscilloscope. Adjust

control)

in the IF pack until the noise disappears from

the oscilloscope screen and the waveform

nearly comes into sync.

Just before shrinking

Figure

Specification

I

Receive the colour bar signal (input field

strength:

Using the signal generator, feed the

frequency

MHz) signal (sinewave) to the

tuner IF output terminal.

Set the tuning switch to the VHF or UHF

position. Keep the tuning button

or depressed until the beating on the oscilloscope screen be minimum.

Set the tuning switch on the normal position.

Adjust

(AFT coil) so that beating on the

oscilloscope screen be minimum.

Figure

IF Pack

FUNCTION OF MAJOR

MECHANICAL PARTS

Take-up pole

Drum

Full erase head

Supply pole base

Tension arm

base

I

Brake shifter

Back tension lever

Head Cleaner)

Dew sensor

Loading motor Master cam

Pinch roller lever Relay shifter lever

Capstan

motor

Reverse guide

Take-up reel disk

Video

search brake

lever

Main supply brake

No.

Full erase head Erase the whole records on the tape in the recording mode.

Tension arm

Detects the tension of tape while running, and brakes

the supply reel disk via the tension band.

Brake shifter

the modes such as stop and playback.

Back tension lever Brakes the supply reel disk to a certain degree to .

prevent tape slackening during “half-loading”,

“loading” and “shifting from playback to video search rewind”.

Main supply brake lever Brakes the supply reel disk to prevent tape slackening

when the unit is stopped in fast forward or rewind

mode. Main take-up brake lever

Brakes the take-up reel disk to prevent tape slackening Rotates synchronously with the master cam, and

when the unit is stopped in fast forward or rewind detects the position of each mode by means of the

mode.

Function

No.

Reverse guide

Pulls out the tape in the video search rewind mode,

and controls the tape drive train height with the upper

and lower guides. Relay shifter lever

Transmits the operation of the master cam to the brake shifter, and operates the reverse guide.

Pinch roller lever Press-fits the tape to the capstan during tape running. The right protrusion switches the clutch of the cassette housing control assembly in “tape eject”, and makes the mechanism eject the tape.

Master cam Turns clockwise during loading, and counterclockwise during unloading, and moves the shifter or the like in accordance with each mode.

Loading motor A motive power which drives the mechanism. It transmits the power to the master cam and cassette housing control assembly via the belt.

Cam switch

internal switch.

Function

Video search brake lever

It is in contact with the take-up reel disk normally, and brakes it to a certain degree. It applies larger brake in unit. This element is activated, when it senses

the video search rewind mode.

Dew sensor An element which detects condensation inside the

condensation, to interrupt the mechanism.

FUNCTION OF MAJOR

Slow brake lever

Loading relay gear

Capstan

motor

Reel belt

MECHANICAL PARTS

Relay gear drive lever

I

VIEW)

IO

Supply loading gear

Reel sensor

Brake

No.

Slow brake lever Gets in contact with the capstan the master cam in the slow still mode, and brakes it to a certain degree.

Capstan

A motive power which runs the tape. It transmits the

power via the reel belt.

Reel belt

Transmits the power to run the tape to the reel pulley.

Brake solenoid Adsorbs and holds the brake shifter in the fast forward and rewind modes, and releases it in the stop mode.

Reel pulley Transmits the power of the capstan reel disk via the reel idler.

motor

Function

motor linking to

5

motor to the

Reel pulley

No.

Reel sensor

An element which sheds the light onto the reflection

plate affixed to the bottom side of the reel disk, and detects the rotation of the reel disk through receiving the reflected light.

Take-up loading gear Shifts the take-up pole base and guide roller via the loading relay gear, and applies the tape around the

assembly, as well as transmits the power to the

supply loading gear.

Supply loading gear

.

Shifts the supply pole base and guide roller via the

take-up loading gear, and applies the tape around the

drum assembly.

Relay gear drive lever Transmits the movement of the master cam to the take-up loading gear via the loading relay gear.

Function

ADJUSTMENT, REPLACEMENTAND

ASSEMBLY OF MECHANICAL UNITS

Here we will describe a relatively simple service

work in the field, not referring to the more

complicated repairs which would require the use of

special equipment and tools (drum assembly

We are sure that the easy-to-handle tools listed below would be more than handy for periodical maintenance to keep the machine in its original working condition.

replacement, for example).

TOOLS NECESSARY FOR ADJUSTING THE MECHANICAL UNITS

The following tools are required for proper service and satisfactory repair.

These Jigs are used for checking and adjusting the reel disk height

A/C Head Tilt Adjusting Jig

6

Cassette Torque Meter

Tension Gauge (3009) .

7

Tension Gauge

Hex Wrench (0.9mm)’

Hex Wrench (1.2mm)

8

Hex Wrench (1.5mm)

Alignment Tape (PAL)

9

Alignment Tape

.

These Jigs are used for checking and

for checking and adjusting the torque of take-up for measuring

There are two gauges used for the

tension measurements, 300 g and

kg.

These Jigs are used for loosening or tightening special hexagon type screws.

This tape is especially used for

electrical fine adjustment.

Drum Replacing Jig

This is used for replacement of the VCR’s upper drum.

No.

Tension Gauge Adapter

Jig Item

Part No.

Code

Configuration

Remarks

This Jig is used with the tension gauge. Rotary transformer clearance adjusting jig.

Special Bladed Screwdriver

Tension Band and Plate Adjusting Jig

Torque Driver JiGTDl200

Box Driver

Reverse Guide Height Adjusting Jig

JiGDRiVER-

AS

1

This screwdriver is used for adjusting the guide roller height.

This Jig is used for adjusting the tension band and tension plate.

This is used to screw down resin-

made parts: the specified torque is 5 kg-

This Jig is used for height adjustment of the A/C head and X-

position.

This Jig is used for height

&@

adjustment of the retaining guide.

This Jig is used for height adjustment of the reverse guide.

the

table as a guide to maintain the mechanical parts in good operating condition.

roller

impedance roller

hole and shaft)

impedance roller flange

Retaining guide

pole

Video head (upper drum

Full-erase head

head

Lower drum

Capstan

Pinch roller

Motor

q

q 0

0

q

q q q q

q

q q

q q q 0

q

q q

cl

q 0

q cl q 0

q

q 0

Possible symptom encountered Remarks

Abnormal rotation or significant vibration requires replacement.

q

Lateral noises

. Head occasionally blocked

Poor S/N ratio, no color

Poor colour, beating

Sound too small or distorted

Poor flatness of the envelope with alignment tape

No tape running, uneven color

No tape running, tape slack

Clean with pure high quality isopropyl alcohol.

Clean tape contact part

with the specified cleaning

liquid.

Clean tape contact area with the specified cleaning liquid.

Reel belt

Loading belt

Cassette loading belt

Tension band

Loading Motor 0

(Automatic Head Cleaner)

Reel block*

* See the table below for servicing the reel block parts.

q

0 0

A 0 No tape running, tape slack

Video search brake lever

Idler gear

Reel Pulley

No tape running, tape slack, no

0

fast forward/rewind motion

0

Cassette not loaded or unloaded

Lateral image swing

0

Cassette not loaded or unloaded

See the chart below.

0

No tape running

0

Clean rubber and rubber

contact area with the

specified cleaning liquid.

Replace the roller of the cleaner when it wears down. Just change the

roller assembly for

new one.

Clean with pure high quality isopropyl alcohol.

Main

NOTE:

If the reading

brake levers

0 Tape slack

Part replacement.

Cl

Cleaning (For cleaning, use a lint-free cloth dampened with pure isopropyl alcohol).

Oil refilling (The indicated point should be lubricated with high quality spindle oil every

out of the specified value, clean or replace the

REMOVAL AND REASSEMBLY OF CASSETTE HOUSING CONTROL ASSEMBLY

l

Removal

Set the cassette ejected condition in the cassette

eject mode. Unplug the recorder from the main source. Follow the procedures below in the specified

order.

a) Remove the cassette loading belt

Disconnect the

Remove the cassette housing installation

screws

Slide and pull out the cassette housing control

assembly @ upward.

(Full Flat Cable)

loading Note the

When the detached, tuck it as in the figure so that it is kept free from grease.

belt is

In removal and reassembly, take care not to hit

the cassette housing control assembly or tools against the guide pin, drum, or the like thereabout.

Place the unit in the eject mode in removal or

reassembly of the cassette housing control assembly.

Load the cassette once onto the cassette housing

control assembly after reassembly. (If the cassette housing control assembly normally operates after this, the phases of mechanism and

the cassette controller are accurately adjusted

after

on.)

MECHANICAL OPERATION CHECK WITHOUT

When power is on, the general operations of the mechanism can be checked without a cassette.

following points.

Check video search rewind and rewind, rotating

the take-up reel disk

normal or reverse direction). If it is not rotated, the reel sensor works to shift the mechanism to the eject mode. When the stop button is pressed, the mechanism

does not stop at a normal stop position. It shifts to the eject mode and stops.

When the stop button is pressed in the playback,

video search rewind, and video search forward

modes, the supply reel disk

for several seconds for elimination of tape slack

in the course of shifting to the eject mode. In such a case, rotate the take-up reel disk somewhat by hand, and the supply reel disk stops, which can reduce the working time.

by hand (in either

keeps on rotating

insert the tab of the Cassette housing control assembly to the mechanism chassis.

Reassembly

.

Before installation of the cassette housing control assembly, place the unit in the stop mode with the power on, then unplug the power cord. (The main body is placed in the eject mode.)

Follow the procedures for removal in the reverse

order.

Notes:

Be sure to unplug the power cord in removal and

Keep the cassette loading belt free from grease.

In case of its adhesion, clean the belt.

In using a magnet screw driver, be sure to keep it away from the A/C head, FE (Full Erase) head, or the drum.

REPLACEMENT OF WORM WHEEL

ASSEMBLY

Cassette housing frame

Figure

Worm wheel

Cassette switch

Worm bracket

tight screw

18X

l

Removal

Unsolder the cassette switch connectors (No.

from the start sensor

Start sensor

Cassette switch

connector

Figure

Lift the start sensor

sensor

fixing hooks inward.

pressing the two start

Start sensor

Place the slider pin just above the worm wheel

assembly (Figure l-7). (The retainer of the slider is locked at two positions. So unlock it as in the Figure Pull out the worm wheel assembly toward you

6

pressing the switch lever upward. (Figure

itch lever

Phase

shaft

Tally mark

washer

Figure

Unscrew one B tight screw to detach the worm bracket. Note:

The worm shaft bearing can easily come-out of

position. So be careful not to lose it.

-Worm bracket

wheel

Figure

Remove the worm shaft assembly, pulley, and

cassette loading belt all from the cassette

housing frame

Worm shaft a

Cassette housing

frame

the

/-Slider

Cassette housing frame

(R)/(L) side

Figure

Reassembly Turn the phase gear clockwise until the slider comes to a halt in the cassette insertion direction. (See the Figure

Insert the set up worm wheel gear assembly into

the cassette housing frame

matching the

mark on the phase gear with the mark on the

worm wheel gear. Detach the cut washer on the

phase gear assembly and the phase gear for

easier installation of worm wheel assembly.

Note: Make sure that the slider pin is in the groove of

the drive gear arm.

Figure

Phase

washer

Figure

wheel

Install the pulley and the cassette loading belt on the worm shaft assembly. Couple the clutch to the clutch lever. And mount them together in the cassette housing frame Note:

Keep in mind that the clutch switching lever

should be in the correct position.

The

mechanism might malfunction if the lever is

slightly out of position. (See page

Cassette loading belt

Tighten one B tight screw.

Note: Do not over-tighten the B tight screw (no more

than

kg-cm), because the lower threads

of the screw hole at the resin-made boss can be

arm

broken. Place the start sensor housing frame Note: Check that the switch connectors (No. are in the cassette switch mounting hole.

Finally resolder the cassette switch connector to

the start sensor

REASSEMBLY OF DRIVE GEAR

Drive gear spring

on the cassette

Worm wheel square hole

Cassette housing frame

-Cassette housing

frame(R)

shaft bear

Worm wheel

Figure

Attach the worm bracket to the worm shaft

assembly. Place them onto the boss on the cassette housing frame

Note:

Insert

before screwing into

Cassette housing frame

Figure l-l

and

Drive gear arm

Drive gear spring

1

Drive gear arm

spring-shaft

(Drive gear bottom view)

Figure

Pass the tip of the drive gear spring

through the square hole of the drive gear

hook the spring in position. Hook one end

of the reciprocating spring to the catch of the drive gear Hook the other end

of the reciprocating spring to the catch of the worm wheel. Insert the pillar

of the drive gear

into the square hole of the worm wheel. Turn the worm wheel somewhat counterclockwise for insertion of the worm wheel to the drive gear

because

the reciprocating spring is at work.

to

REPLACEMENT OF CASSETTE LOADING BELT

Cassette

Remove the start sensor

Remove the worm shaft assembly Replace the cassette loading belt

Notes:

housing frame

bracket

Figure

from the cassette housing frame

Worm bracket

and worm

with a new

one.

Do not over-tighten the B tight screw which holds the worm bracket in position. The specified torque is

0.5 Make sure that the cassette loading belt is free from grease.

If stained with grease, clean the belt with the cleaning liquid. Perform checking of the clutch switch lever for proper action.

CHECKING THE CLUTCH SWITCH LEVER

l

Checking

Place the mechanism in the cassette eject mode

when removing and attaching the cassette

housing from and to the mechanism chassis. Make sure enough that each part in the cassette housing such as the clutch switch lever is in position. If not, it causes malfunction. Note: Figure

the cassette eject mode.

shows the position of each part in

Figure l-l

First make sure that the tip of the switch lever is held at the rib of the drive gear

Check that the rib of the cassette housing frame

and the concavity of the clutch lock lever are

engaged.

Finally be sure that the relationship between the clutch lever and the clutch, as well as between the clutch and the pulley, are correct as in the

Figure l-1

.

Check that the clutch is engaged

with the pulley through the coupling.

Figure l-l

Resetting Take the following steps to reset the clutch if it is unlocked or if the switch lever and the clutch lock lever are unlocked.

lever

gear

lever

Rib of cassette housing frame

Figure

lock lever

6.

Shift the slider by turning the coupling in the arrow direction (clockwise) until the slider pin is at the bottom of the slider groove as shown in

the Figure l-16. (The loading mode)

Note: Note that the slider is mechanism. housing frames

Unlock the locks on cassette

and

side before shifting

a lock

the slider.

When the position is set as shown in the Figure 4-

16, push the clutch release lever in the direction

of the arrow by hand until the clutch lock lever

becomes tightly locked by the rib of the cassette housing frame

Then turn the coupling counterclockwise until the slider reaches the cassette insertion opening

and the reciprocating spring is activated.

Note:

There is no need to unlock the slider when shifting the slider to the cassette insertion opening. Just keep shifting the slider.

REPLACEMENT OF LOCK RELEASE LEVER

l

Removal

Place the slider in the cassette down position.

(Turn the coupling on the worm shaft clockwise until the slider is in the cassette down position.) Note: Before shifting, unlock the slider.

Slightly widen the cassette housing frames

and the slider assembly off the grooves of the

cassette housing frames.

to unhook the slider holders

and

Pulley

of

Remove the lock release lever from the slider

holder(R)

l

Reassembly

Follow the steps for removal in the reverse order.

(See Figures

and

Attach the lock release lever to the slider holder

Slide the slider holder

two catches of the slider holder

downward so that the

fit the

opening of the slider.

Slightly widen the cassette housing frames, and

set the pins of slider holders

and

into the grooves of the cassette housing frames. Note: Check if the pins of the slider holders

and fit the grooves of the cassette housing frames, and if the drive gear arm is sufficiently engaged with the slider holders.

Turn the coupling counterclockwise until the

slider is at the cassette insertion opening.

TO RUN A TAPE WITHOUT THE CASSETTE HOUSING CONTROL ASSEMBLY

Plug in the power cord. Turn on the power switch. Open the lid

Hold the lid with two pieces of vinyl tape Set the cassette tape in the mechanism chassis. Stabilize the cassette tape with a weight prevent floating. Perform running test.

of a cassette tape by hand.

to

Figure l-l

Lift the slider holder

upward about the slider by pressing two catches with a thin tip screw driver. catches.

Take care not to damage the

lock catch

Figure

/-Slide

off

Note: The weight should not be more than

Figure

REPLACEMENT AND HEIGHT CHECKING

AND ADJUSTMENT OF REEL DISKS

Remove the cassette housing control assembly. Set the mechanism in the playback mode with no cassette tape in place. Unplug the power cord. Set the idler gear in the center (neutral).

Removal (Supply reel disk)

Remove the tension band deform it.)

Unscrew the screw @ and remove the supply reel retainer assembly

Release the supply reel disk catch tension lever Pull the supply reel disk upward.

Notes:

Take care not to deform the tension band. Check and adjust the tension pole position. (See

page 30.)

Be careful not to damage the gear and the idler

gear on the supply reel disk.

Press the tension band in the direction of the

arrow for removal (See Figure

(Take care not to

and back

Removal (Take-up reel disk) Unscrew the screw

and remove the take-up reel retainer. Release the take-up reel disk catch Pull the take-up reel disk

Take-up reel disk

Figure

upward.

e-up reel

retainer

Note: When the tension band is pressed in the direction of the arrow for removal, the catch is hard to be deformed.

Reassembly (Supply reel disk) Clean the reel disk shaft Release the supply reel disk catch

and apply oil to it.

and back

tension lever

Install a new supply reel disk Replace the tension band

onto the shaft.

around the supply

reel disk, and insert it to the hole of the tension

arm.

Replace the supply reel retainer assembly place, and tighten up the screw

Notes:

Take enough care not to deform the tension

band during installation of the supply reel disk. Be careful not to damage the supply reel disk gear, back tension lever, supply reel disk catch, or the Ii

with tools.

5 Tension band

Q

in

Figure

Supply reel

disk catch

Reassembly (Take-up reel disk) Clean the reel disk shaft Release the take-up reel catch

and apply oil to it.

and video

search brake lever

Install a new take-up reel disk @ onto the shaft. Replace the take-up reel retainer

in position

and tighten up the screw Note: Take care not to damage the video search brake lever.

Take-up

reel disk

Apply a thin tip driver to the arrow position in releasing for easier setting of the take-up reel disk.

Clean the reel disk shaft well, and

oil to it.

Set the master plane releasing the reverse guide by a finger.

guide

Master

Figure

For height adjustment, press the reel disk with a

finger, and turn it right and left with a screwdriver (see Figure

(a)).

Check that the reel disk is lower than part A but

higher than part

If the height is not correct,

adjust the height adjusting screw (see Figure

Note: Whenever replacing the reel disk, perform the height checking and adjustment.

Figure

* After reassembly, check the video search rewind

back tension (see page

and check the brake

torque (see page

l

Height checking and adjustment Note: Place the master plane onto the mechanism unit,

taking care not to hit the drum (see Figure

Setting

Master plane

L

Reel disk

Slide it right and left, and check contact with

Reel disk height

‘,‘, ,

adjusting jig

‘-

/Mechanism chassis

’

Figure

CHECKING AND ADJUSTMENT OF TAKE-UP

TORQUE IN FAST FORWARD MODE

l

Remove the cassette housing control assembly.

l

Setting

Torque gauge

CHECKING AND ADJUSTMENT OF TAKE-UP TORQUE IN REWIND MODE

l

Remove the cassette housing control assembly.

l

Setting

Torque gauge

Set the scale to

l

Checking

Turn the torque gauge slowly (one rotation every 2 to 3 seconds) by hand in the take-up direction

Setting

Figure

Take-up reel disk

or more

Set the scale to

l

Checking

Turn the torque gauge slowly (one rotation every 2 to 3 seconds) by hand in the take-up direction

Figure

or more

The gauge is held at its maximum value.

The gauge is held at

Id

Figure

l Adjustment

its maximum value. (Red mark)

Take-up direction

If the take-up torque is outside the range, clean

the capstan

motor pulley, reel belt and reel

pulley with cleaning liquid, then recheck the

torque.

If the take-up torque is still out of range, replace

the reel belt.

Notes:

Hold down the torque gauge so that it may not

fly off.

When checking the take-up torque, do not keep

the reel disk locked for a longer time.

Figure

l

Adjustment

If the take-up torque is outside the range, clean

the capstan

motor pulley, reel belt and reel

pulley with cleaning liquid, then recheck the

torque.

If the take-up torque is still out of range, replace

the reel belt.

Notes :

Hold down the torque gauge so that it may not

fly off.

When checking the take-up torque, do not keep

the reel disk locked for a longer time.

CHECKING AND ADJUSTMENT OF TAKE-UP TORQUE IN PLAYBACK MODE

Remove the cassette housing control assembly.

the lid of the cassette torque meter, and

hold it with two pieces of vinyl tapes.

Open here

Cassette torque meter

Load a cassette torque meter into the unit.

CHECKING AND ADJUSTMENT OF TAKE-UP TORQUE IN VIDEO SEARCH REWIND MODE

l

Remove the cassette housing control assembly.

Checking

Push the play button to place

the unit in the playback mode.

Push video search rewind button to place the unit in the video search rewind mode.

Torque gauge

Figure

l

Checking

Set value

Check that the torque is in the range of

The torque fluctuates due to the rotational

deviation of the reel drive unit. Use the center of the fluctuation as the value.

Place the unit in the

record mode, and check

that the take-up torque is within the range.

Place the torque gauge on the supply reel disk, and turn it counterclockwise very slowly (one rotation every 2 to 3 seconds) and check

that the torque is within the set value

Figure

Note:

Set the torque gauge securely on the supply reel

disk. If it is not secure, the measurement will be incorrect.

l

Adjustment

If the take-up torque in video search rewind mode

is outside the range, replace the supply reel disk.

Note: The torque fluctuates due to the rotational deviation of the supply reel disk. Use the center of the fluctuation at the value.

Supply reel disk

l

Adjustment

If the take-up torque in the playback mode is

outside the range, replace the take-up reel disk.

Note: Stabilize the cassette torque meter to prevent floating.

CHECKING THE FAST FORWARD BACK TENSION

l

Remove the cassette housing control assembly.

l

Checking

CHECKING THE VIDEO SEARCH REWIND

BACK TENSION

Remove the cassette

l

Checking

housing control assembly.

fast forward mode.

Place the torque gauge on the supply reel disk, and turn it clockwise very slowly (one rotation every 2 to 3 seconds) and check that the torque is within

Figure

Supply reel disk

Note :

Set the torque gauge securely on the supply reel

If the torque gauge is not securely set on the

disk.

reel disk, measurement will be incorrect.

CHECKING

l

Check

REWIND BACK TENSION

Push the play button to place

the unit in the playback mode. button to place the unit in the

Place the torque gauge on the take-up reel disk, and turn it counterclockwise very (one rotation every 2 to 3 seconds) and check

that the torque is within the set value

5 2Ogcm.

Push the video search rewind

videosearch rewind mode.

Torque gauge

Figure

Take-up reel disk

Note :

Set the torque gauge securely on the take-up reel disk. If it is not secure, the measurement will be

incorrect.

CHECKING THE PINCH ROLLER PRESSURE

Remove the cassette housing control assembly.

l

Place the unit in the

Take-up reel disk

rewind mode.

Place the torque gauge on the

take-up reel disk, and turn it

counterclockwise very slowly (one rotation every 2 to 3 seconds) and check that the torque is within

Figure

Note: Set the torque gauge securely on the take-up reel

disk. If it is not secure, the measurement will be

incorrect.

unit in the playback mode.

Capstan shaft

Figure

Detach the pinch roller from the capstan shaft.

Set the tension gauge by hooking the tension

gauge adapter onto the pinch roller shaft.

Gradually release the pressure to allow the pinch

roller to touch the capstan shaft. When the pinch roller just touches the capstan shaft, read the indication on the gauge.

Check that the reading of the tension gauge is in

the range of

to

CHECKING AND ADJUSTMENT OF TENSION POLE POSITION

l

Remove the cassette housing control assembly.

l

Setting

At the beginning of the tape

check that the tension pole’s left side is aligned with the supply impedance roller’s center by sight.

Check that the end of the tape is neither curled

against the flange of the supply impedance

roller nor over it.

During the video search rewind mode with no

cassette tape in place, check that the supply reel disk is free from the tension band.

l

Position adjustment (record mode)

When the tension pole is at the right of the supply

impedance roller’s center:

tension band adjustment bracket in the direction of the arrow using a tension band and plate adjusting Jig until it is in the set value range (center). Then secure it with the tightening screw.

Guide roller A

head

impedance.

roller

Check the left side position (by sight).

Place the unit in

the record mode.

T

roller B

Center

I

impedance roller

Tension pole

Tension band

and plate adjusting jig

Figure

l

Position adjustment (record mode)

When the tension pole is at the left of the supply

impedance roller’s center:

tension band adjustment bracket in the direction of the arrow using a tension band and plate adjusting

Jig until it is in the set value range (center). Then secure it with the tightening screw.

Tension and plate adjusting jig setting hole

l

Checking

I. The guide rollers (A,

Figure

Video Cassette tape (E-l

operate to bring the tape outside the cassette tape and simultaneously the tension pole moves to the left, loading the tape.

At that time (loading completed), check the

position of the tension pole.

g

I

Supply impedance

roller

Tension pole

Tension band

and plate

adjusting jig

Tension band adjustment bracket

Figure

CHECKING AND ADJUSTMENT OF

RECORD

l

Remove the cassette housing control assembly.

l

Checking

PLAYBACK BACK TENSION

Tension spring

spring

Weight a

chassis

.

I\’

Push the record button to place the unit

in the record mode.

Figure

Put a cassette torque meter into the unit.

Push the record button to place the unit

record mode.

Check that the back tension indicated by the

gauge is within the set range

Notes:

Make sure that the video cassette tape is over

the retaining guide.

Make sure that the tape is not slack nor

damaged at either end.

to

the

Tension spring hook plate

Figure

Tension spring

hook plate

CHECKING THE BRAKE TORQUE

l

Checking the brake torque at the supply side

Torque gauge

reel

l Adjustment

If the reading of the cassette torque meter is less

than specified, move the tip of the tension spring

hook plate toward the hole A.

If the reading of the cassette torque meter is

more than specified, move the tip of the tension spring hook plate toward the hole Note: Put a thin screw driver it toward you, and turn it for easier shift of the

tension spring hook plate in the direction of A or

in the shaft hole, lean

idler gear

Mechanism chassis

Figure

Remove the cassette housing control assembly.

Place the mechanism in the stop mode by

unplugging the power cord in the fast forward

or rewind mode.

Slowly rotate the torque gauge in the clockwise

direction and counterclockwise direction of the supply brake so that the reel disk and the indicator of the torque gauge rotate at an equal rate. Check that the values are within

the range of

direction

brake torque in the

as high as that in the

direction =

to

direction is at least twice

direction.

to

and that the

l Checking the brake torque at the take-up side

chassis

REPLACEMENT OF MAIN BRAKE

Remove the reel belt and the reel block

Flat Cable). Remove the cut washer Unscrew the four screws

up reel retainer. Remove the reel block assembly Remove the cut washer

pulley.

Unscrew the two screws

assembly. Unhook the back tension lever spring

remove the back tension lever

hook under the reel chassis.)

Open the shifter latch

shifter assembly

Release the reel disk catchesand

the left and right reel disk assemblies

Finally remove the main brake levers

main brake spring

off the brake shifter.

and then the

downward.

first and then the reel

and detach the idler

and remove the brake

then remove

.

(Full

and

(Undo the

and

and the

Figure

Remove the cassette housing control assembly.

Slowly rotate the torque gauge in the clockwise

direction and counterclockwise

direction of the take-up brake so that the reel

disk and the indicator of the torque gauge

rotate at an equal rate. Check that the values

are within the range of

direction

that the brake torque in the

direction

to

and

direction is at

least twice as high as that in the CW direction.

Adjustment of the brake torque at the supply

side and the take-up side

If the supply or take-up brake torque is outside the range, clean the supply or take-up reel disk break lever felt, then recheck the torque.

If the supply or take-up brake torque is still outside the range, replace the main brake or the main brake spring.

Figure

Note:

When the main brake is replaced, perform the

height checking and adjustment (see page

and

the brake torque checking (see page

REPLACEMENT OF A/C (Audio/Control) HEAD

Remove the cassette housing control assembly. Place the unit in the unloading mode, and

unplug the power cord.

l

Removal Loosen the tilt adjusting screw Remove the azimuth adjusting screw Remove the A/C head screw Unsolder the A/C head

head assembly.

Notes:

After replacement, be sure to perform the

adjustment of the tape drive train (see page

Under any circumstances, avoid touching the head. Clean the head, if touched with your

finger, with alcohol.

Take care that the azimuth spring does not fly

off when removing the A/C head screw.

4

soldered to the

Figure

l

Adjustment

[A/C head tilt angle]

Set the mechanism to the loading mode. Place the A/C head tilt adjusting Jig

3 Slowly turn the tilt adjusting screw

screw driver until there is no gap between the Jig and the A/C head.

with a

Pay attention to

Figure

l

Replacement

Solder the removed A/C head

A/C head assembly.

The A/C head assembly is attached so that the

A/C head arm and

parallel to each other.

head plate are roughly

onto a new

Solder

A piece of white paper

1

Screw driver

New

head

Never touch the head

head arm

Figure 1-48.

[A/C head height rough adjustment]

head

adjusting

Weight

Roughly adjust the height of the AK head by turning

the

head adjusting hexagon nut with the specialized box drive until the tape is in the position shown

Reverse guide

adjusting jig

of 5009

chassis

HEIGHT ADJUSTMENT OF REVERSE GUIDE

Note: Before the rough adjustment of the tape drive

train, check that the retaining guide height is within the value in Figure

Jigs.

height-\

-Reverse guide Reverse guide

height

.

To readjust the height, remove the cut washer from behind, take out the spring, lift the

reverse guide and add a washer.

by using the special

7

Reverse guide

head

Adjust the nut visually so that

.

the control head is visible to

mm below the bottom

of the tape.

Figure

Adjust the height using

of washers

Spring

Mechanism chassis

.-Spring

(iron flat)

washer

Figure

8X

ADJUSTMENT OF TAPE DRIVE TRAIN

Remove the cassette housing control assembly. Check and adjust the position of the tension

pole. (See page

Check and adjust the video search rewind back

tension. (See page 28.) Set the tilt angle of the A/C head. (See page Rough adjustment of tape drive train.

Connect the oscilloscope to the test point for

the synchronism of the oscilloscope to EXT. The the head switching pulse

Loosen the setscrew at the lower part of the guide roller, and adjust it with an adjusting screw driver

roller turns smoothly. (Do not overloosen the setscrew, which causes insecurity of the guide

roller.) (See Figure Set the alignment tape (monoscope pattern)

on the reel disk, and place the unit in the

playback mode.

(Place a

prevent floating of the cassette tape.)

envelope output

signal is to be triggered by

so that the guide

g weight on the cassette tape to

Set

Wrinkles at upper flange

Wrinkles at lower flange

Clockwise

Counterclockwise

Guide roller

Hexagon

Figure

Change the envelope waveform from MAX to

or

is obtained on the waveform.

adjust the guide rollers on the supply side and

take-up side using an adjusting screw driver

until a flat response can be obtained.

Turn the

head tilt adjusting screw with a screwdriver to prevent the tape from wrinkling at the upper and lower flanges of the fixed guide.

Wrinkles at the upper flange

Turn the

above adjusting screw clockwise, as shown

in Figure

(a).

Wrinkles at the lower flange : Turn the

above adjusting screw counterclockwise, as shown in Figure

Figure

Notes:

Place the tracking control in the center position, and adjust the X-position adjusting nut so that

the

envelop becomes maximum for easier rough adjustment of the tape drive train. In the rough adjustment, pay particular attention to the outlet side.

. .

Loosen the setscrew o

Figure 1-54.

Figure

X-position adjusting nut

Head switching pulse

envelope

Azimuth adjusting screw

Figure

Adjustment of A/C head height and azimuth

a) Connect an oscilloscope to the audio output.

(Pin

of EL connector)

Use the alignment tape and play back its

audio 7

signal (monoscope pattern for

video signal). Adjust the azimuth adjusting

screw to obtain the maximum audio output on an oscilloscope. (See Figure

Use the alignment tape and play back its

audio 1 kHz signal (colour bar for video signal) and slowly rotate the A/C head height adjusting nut with the special box driver to obtain the maximum audio output.

Perform the adjustment in

again.

After this adjustment, apply glyptal to the

screws and nuts to fix them.

Figure

Adjustment of tape drive train and X-Position.

a) Connect the oscilloscope to the test points

for

CHROMA envelope output. Set the synchronism of the oscilloscope to EXT. The

signal is to be triggered by

the head switching pulse (TP2202).

Play back the tape drive train alignment tape.

Push the

envelope waveform from MAX to

or

button to change the

and

on the supply and take-up sides with an adjusting screw driver, to obtain an envelop waveform that is as flat as possible.

If the tape is above or below the helical lead,

the

waveform will take the shape

shown in Figure

Adjust for maximum flatness of the envelope

the step in page

Adjustment

When the tape is above the helical lead.

Supply side

Take-up side

Supply side guide Take-up side guide roller rotated in roller rotated in clockwise direction (lowers guide roller) to flatten envelope. flatten envelope.

clockwise direction

(lowers guide roller) to

Figure

When the tape is below the helical lead.

Supply side

Supply side guide

roller rotated in counterclockwise direction (raises guide

roller) to make the tape float above the

helical lead. The supply side guide roller is then rotated in the clockwise direction to flatten the envelope.

Take-up side

Take-up side guide

roller rotated in counterclockwise direction (raises guide roller) to make the tape float above the

helical lead. The take-up side guide

roller is then rotated in the clockwise direction to flatten the envelope.

8X

Push the

that a flat response is obtained on the

envelope waveform.

Secure the guide roller by tightening the

guide roller setscrew in the unloading mode.

Play back the tape drive train alignment tape

to check that the envelope waveform does

not change.

Adjustment of A/C head X-position.

a) Push the (

same time to the preset mode.

Rotate the X-position adjusting nut with an

adjusting box driver, and adjust the position for maximum head switching pulse low side envelope.

Adjust the playback switching point.

Check the flatness of the envelope waveform

and sound by playing back a recorded tape.

X-position adjusting

or (-) tracking button to check

and

tracking buttons at the

nut

head

l

Reassembly

Mount the capstan motor on the mechanism

chassis making sure not to allow the capstan shaft to hit the mechanism chassis, and attach it with the three screws.

Insert the

into the capstan

motor

control

Attach the reel belt.

Notes:

After installing the capstan

to rotate the capstan

motor, be sure

motor and check the

movement.

Check and adjust the servo circuit.

REMOVAL AND REASSEMBLY OF THE LOADING GEAR BLOCK

Notes:

Remove the cassette housing control assembly. Remove the reel belt. Remove the reel block.

mm

Main

chassis

Figure

REPLACEMENT OF THE CAPSTAN D.D.

(DIRECT DRIVE) MOTOR

l

Remove the cassette housing control assembly.

l Removal (Follow the order of

numbers.)

Remove the three screws.

l

Notes:

Remove the washer

Removal

Use care not to deform the parts hooked to the

slow brake shaft cap, take-up loading gear and supply loading gear as shown in Figure

Figure

in removing the loading gear, secure the guide

roller with a rubber band or the like beforehand

for easier reassembly.

Remove the E-ring

Loading relay gear

Figure 1-61.

Figure

Remove the slow brake spring Remove the washer Remove the slow brake lever Remove the E ring Rotate the take-up loading gear, take-up loading arm assembly, supply loading gear and supply loading arm assembly slightly in the loading direction, and take them

all out. Remove the E ring Remove the relay gear drive lever

Reassembly Reverse the procedure. Be sure to match the tally marks on the gears.

Screws

Figure

Note: When using a magnetic screw driver in removal of three screws, do not allow the magnetic driver to

hit the A/C head or drums.

Figure

Notes:

When reassembling, apply specified grease to the following points; all the gear teeth, all the

gear shafts and the cam groove of loading relay gear.

Be careful not to deform the supply/take-up

loading arms. Be careful to keep clean the slow brake lever felt. Be also careful to keep the outer surface of the capstan

motor free from dust and dirt. (If stained, the MR (Magnet Resistor) element might be damaged.) Take care not to deform the anti-fall hooks of the slow brake lever, slow brake shaft cap and supply/ take-up loading gears more than required.

REMOVAL AND REASSEMBLY OF LOADING BLOCK

l

Removal Remove the cassette loading belt Unscrew the three screws Pull the loading block upward.

Reassembly Turn the master cam all the way counterclockwise.

the tally mark on the cam switch with the

matching mark.

Fit the loading block and the

master cam with each other. Tighten up the

three screws.

Tally mark

Cam switch

Figure

Finally connect the leads and apply the cassette loading belt.

Notes:

Be careful not to scratch the gear. Be careful not to stain the belt. If dirty, clean it

up with the specified cleaning liquid.

REPLACEMENT OF LOADING MOTOR

Set the cassette ejected condition by placing the

unit in the cassette eject mode. Unplug the power cord. Remove the loading block in accordance with

the statements and drawings above.

8X

I

Removal

Figure

Unsolder the leads Unlock the left and right catches

switch off the loading block. Take out the cam switch and loading block

from the loading motor.

of the cam

(See Figure

marks

block

Loading mot

Note:

When press-fitting the loading

motor pulley, keep the pressure less than 5 kg, and the gap between the motor and pulley should be

Figure

Set the loading block

position.

Resolder the leads to the loading motor.

Finally place the loading block (See page

Attach the loading belt.

Figure

and the cam switch in

mm

mm.

Pull up the cam switch pressing the catches. Remove the cam switch

Catches of cam switch

Take out the loading belt Pry up the back end of the loading motor with a

screw driver or the like as in Figure out the motor.

screwdriver or the

like here. Pry UP the back end of the

loading motor and

take out the motor.

l

Reassembly

Remove the loading motor, and mount a new

loading motor as in Figure

Place the loading motor so that its label is visible

as screw hole at the motor shaft, protuberance *on

the

marked with the arrow are mated with each

other.

a

in Figure

block, and the motor’s back end

together with the loading btock

Figure

and take

Motor label

Figure

Make sure that the

Loading belt

Q

REPLACEMENT OF MASTER CAM

l

Removal Remove the E ring Remove the pinch roller lever Pull out the master cam

Master cam

I

upward.

Pinch roller lever

Pinch

roller lever

Bottom side of master

lever cam follower

(Place the relay shifter

lever to the unloading position.)

brake lever cam follower

Figure

cam

Reassembly Place the relay gear drive lever in the unloading

state.

Place the relay shifter so that it is in contact with the reverse guide spring hole in the mechanism chassis. Release the slow brake lever with a finger to bring it away from the capstan (in the direction of arrow). Then place the master cam so that the D cut-off part of the master cam faces the direction of arrow.

Turn the master cam somewhat clockwise until

the pinch roller lever’s cam follower goes into

the master cam’s groove (marked with arrow).

Mount the pinch roller lever and then attach the

E ring.

Rotate the master cam by hand to make sure all the four levers (relay gear drive lever, pinch roller lever and relay shifter lever) are in the cam grooves in place. Mount the loading block. (See page

Notes:

Be careful not to scratch the teeth and grooves

of the master cam.

After installation of the master cam, be sure to

rotate the master cam by hand before installing the loading block.

If the levers are in wrong

position, the master cam and the levers may get damaged when the motor stares. Apply specified grease to the master cam’s

3

grooves and teeth.

Unsolder the leads.

and tighten the

Turn

Figure

l

Reassembly

Notes:

Before setting the drum, check that there are no scratches or dust on the edge of the surface and circumference of the disk.

Before setting the drum, check that there are no scratches or dust on the internal surface and

edge of the surface of the upper drum.

On assembling these parts, insert the upper drum onto the disk with care, so that the upper drum is not tilted. When assembling these parts, do not allow dust

or dirt come between the disk and the upper drum.

Do not use excessive force when driving in the screws.

REPLACEMENT OF UPPER DRUM

Note: The gap between the lower drum and the upper drum is very accurate, in the order of microns, and care should be paid to their replacement. Even a slight amount of foreign material will affect the

accuracy of their reassembly.

l Replacement (Follow the order of the indicated

numbers.)

Notes:

Avoid touching the drum surface

hands. Pull out the upper drum with care so that it may not be tilted, and replace it with the upper drum replacing jig using care not to damage the disk

circumference.

Do not hit the screws when tightening them.

Figure

Set the new drum.

Fasten the upper drum in place with the two screws. Solder the leads. Note: Soldering should be performed quickly and carefully without touching adjacent patterns. After replacement, be sure to check the tape drive train adjustment (see page 34.) and the following electric adjustments.

l

Adjustment of the playback switching point.

l

Checking and adjustment of the X-position.

l

of

and

slow

8X

18X

REPLACEMENT OF D.D. MOTOR

Put the unit in the cassette eject position. Unplug the power cord.

l

Removal (Reverse the order in reassembly.) Remove the Remove the two

Pull out the

Remove the three

Remove the

Notes:

When removing the

assembly, use care not to hit the loading

relay gear.

Secure the

installation positioning holes in the assembly and lower drum assembly match.

Be careful not to damage the upper drum or the

video head.

Be sure that the hall device and the

assembly are not damaged by the assembly or other parts.

After installation, adjust the playback switching

point.

rotor assembly setscrews

rotor

stator setscrews

stator assembly

rotor assembly or

rotor assembly so that the

rotor

REPLACING THE

CLEANER)

(AUTOMATIC HEAD

setscrew

Figure

setscrew

positioning

rotor

Figure

l

Removal

Unhook pat-t

ass

,

arrow.

with a finger in the direction of

Hold the rib (marked with an arrow) of the

with electrician’s pliers or the like, and

pull the

upward in the direction of arrow

Note:

To pull out the AHC

l

Reassembly

Push down the

arrow

Make sure that the

hold the AHC lever down.

in the direction of

is secured in

position by the hook of part

Notes:

Be careful to keep the

out of contact

with the drum.

Be careful to keep the cleaner section of the

free of grease of contaminants.

ADJUSTMENT OF THE

VCR ELECTRICAL CIRCUITRY

Notes:

Before the adjustment:

Electrical adjustments discussed here are often required after replacement of electronic mechanical parts such as video heads. Check that the mechanism and all electric components are in good working condition prior to the adjustments, otherwise adjustments can not be completed.

l

Instruments required:

signal generator

e oscilloscope

milli-voltmeter

Frequency counter Blank video cassette tape Screwdriver for adjustment

n

SERVO CIRCUIT ADJUSTMENT

Adjustment of head switching point

Measuring instrument

Dual-trace oscilloscope

voltmeter

@Alignment tape

Extension connector

AL

AL)

Mode Cassette Test point

Control

Specification

Play the alignment Short circuit test points

the A/V Jack housing (See Note below)

Connect a dual trace oscilloscope to the VIDEO

OUT (pin (Trigger the oscilloscope with the head switching pulse on TP2202.)

Adjust

head switching pulse is 6.5H (lines) ahead of the

vertical sync as shown in Figure

Playback

Alignment tape

VIDEO OUT (pin

connector) to

(Trigger) to

(Located on the Y/C

head switching point

adjustment control

H (lines)

or remove the cassette

to set the auto tracking to center.

of EL connector) and TP2202.

so that the leading edge of the

of EL

1

and

on

HEAD . SWITCHING PULSE

Figure

Notes: To make this adjustment, disable the AUTO TRACKING function. The AUTO TRACKING function is disabled in the following cases. (In the playback mode only.)

the cassette housing control

removed, press both tracking control buttons of the remote control unit at the same time to set the tracking in center.

When test points

jack

are short-circuited.

(lines)

and

V-sync.

is

on the A/V

n

Test points layout of VCR Main Unit.

I

1

I

0

I

Adjustment of PAL System tracking Preset

Measuring instrument

Mode

Monitor TV

Recording and playback on recording tape at

and

8

U

mode.

~10~

Figure 2-2.

ED

I

Adjustment of

tracking Preset

Measuring instrument

Mode

.

I

and

I

mode.

slow

System

Monitor TV

Recording and playback on

recording tape at

EL

Input signal

Test point Adjusting point

Specification

Play back the

PAL System Commercial broadcastor video signal.

Monitor screen

Tracking control button

No noise bar on the monitor TV screen.

self-recorded tape in the PAL

System slow mode.

Make the test points

and

circuited in the Jack

Be sure that the

mode display

disappears

on the screen. Remove the short-circuit. Adjust the tracking control using the TRACKING

buttons on the remote controller so that there is no noise on the screen.

Play back the

self-recorded tape in the PAL

System Slow mode.

Make the test points

and

circuited in the Jack Be sure that the

mode display

disappears

on the screen. Remove the short-circuit.

buttons on the remote controller so that there is no noise on the screen.

Input signal

Test point

Adjusting point

Specification

Play back the

system

Commercial broadcast or video signal.

Monitor screen

Tracking control buttons

No noise bar on the monitor TV screen.

self-recorded tape in the

System slow mode.

Make the test points

and

circuited in the Jack

Be sure that the

mode display

disappears

on the screen. Remove the short-circuit. Adjust the tracking control using the TRACKING

buttons on the remote controller so that there is no noise on the screen.

Play back the

self-recorded tape in the

System Slow mode.

Make the test points

and

short-

circuited in the Jack

Be sure that the

mode display

disappears

on the screen.

Remove the short-circuit.

the tracking control using the TRACKING buttons on the remote controller so that there is no noise on the screen.

I

18X

Adjustment of PAL System still

vertical sync

Measuring instrument

Mode

Input signal Test point Adjusting point

Specification

Flay back the self-recorded tape in

System still mode.

Using the TRACKING buttons on the remote

controller, make adjustment so that jitter becomes minimum.

Now press the STOP button to stop the tape.

Adjustment of

Monitor TV Still picture playback

PAL self-recording tape Monitor screen Tracking control buttons (

No noise jitter

System still picture

),

vertical sync

PAL

Y/C CIRCUIT ADJUSTMENT

Adjustment of video E-E level

instrument Mode

I

Input signal

Test point

I

Control

Specification

Connect an oscilloscope to the VIDEO OUT

(pin

Feed a

and put the unit in

Adjust

(See Note below)

of EL connector).

as shown in Figure

I loscope

E-E or Record

I

PAL colour bar

VIDEO OUT (pin

I

bar signal to the VIDEO IN jack

so that the signal amplitude is

of EL connector)

E-E level control

input mode.

I

Measuring instrument

Mode

Input signal Test point Adjusting point

Specification

Play back the self-recorded tape in the

System still mode.

Using the TRACKING buttons on the remote

controller, make adjustment so that jitter becomes minimum.

Now press the STOP button to stop the tape.

Monitor TV Still picture playback

I

self-recording tape

Monitor screen

I

Tracking control buttons ( + ),

No noise jitter

I

Figure 2-3.

I

Note:

After this adjustment, check the deviation of FM

luminance signal.

adjustment.)

(Frequency and Deviation

Adjustment of

Measuring instrument

Mode

I

Input

I

Test point

I

Control

I

Specification

DC Voltmeter

E-E or Record

I

PAL colour bar Vp-p)

O.lV

I

I I

Feed a

and put the unit in

Connect the DC voltmeter to test points

Adjust

bar signal to the VIDEO IN jack

input mode.

and

so that the DC voltmeter reads

points

layout of Y/C Unit.

Adjustment of white clip

Measuring instrument

Mode

I loscope

E-E or Record

LEVEL

Figure

----

CLIP

DEVIATION

cl

PB CHROMA HEAD SWITCHING PULSE

REC SIGNAL

Note:

From sync tip to white peak, the level is The white clip level is (There is no dark clip adjustment.)

above the white level.

Input signal

Test point

Control

Specification

Connect the oscilloscope to test points

Feed the

and put the unit in

Adjust

signal is clipped at 190% as shown in Figure

PAL colour bar

white clip control

5% (See note below)

and

bar signal to the VIDEO IN jack

input mode.

so that the overshoot of the video

N

.

. .

.

l-

I

WHITE CLIP LEVEL

Figure 2-5.

Adjustment of FM carrier frequency and deviation

Measuring

instrument Mode

Input signal

Test point

Control

Specifications

Be sure that R2202 (E-E LEVEL) has been

correctly adjusted.

Connect an oscilloscope to the VIDEO OUT (pin

of EL connector).

Connect a frequency counter to test points

Frequency counter

Oscilloscope Record/Playback PAL colour bar

VIDEO OUT (pin

of EL connector)

FM carrier control Deviation control

0.05MHz O.lVp-p

of playback level

Measuring instrument

Mode Cassette Test point

Control Specifications

Connect an oscilloscope to the VIDEO OUT (pin

Play the

tape and adjust

amplitude is

I

Playback Alignment tape VIDEO OUT

(pin

bar portion of the alignment

of EL connector)

playback level control

vp-p

so that the signal

as shown in Figure

Put the unit in

signal to the VIDEO IN jack. (Disconnect any cable from video input terminal.)

Under this condition, adjust

frequency counter reads

Feed the PAL standard

VIDEO IN jack and adjust

frequency counter reads Repeat step 5 Under this condition record the

on tape, rewind and playback. Make sure that the amplitude of the playback

bar signal is

Figure the PLAYBACK LEVEL adjustment.

If it is out of specified value, check

input mode. Do not feed any

so that the

bar signal to the

so that the

7 a few times.

Vp-p as shown in

and retry this

. . . . . . . . .

bar

Figure 2-7.

Figure

. . . . . .

n

AUDIO CIRCUIT

Checking of audio play-back level

Measuring instrument

Mode

I

Input signal

Test point

Specification

Playback the Alignment tape.

level adjusting signal)

Connect an AC

OUT (pin

Make sure that the output level is

AC milli-voltmeter

Playback

I

Alignment

kHz level adjusting signal.)

AUDIO OUT

(pin

of EL connector).

of EL connector)

9

to the AUDIO

9

Checking of audio record level

Measuring instrument

Mode

I

Input signal

I

Test point

AC

I

Record/Playback

I

AUDIO OUT (pin

of EL connector)

or

Connect an AC milli-voltmeter to test points

+ ) and

(Use Set the unit in recording mode. Adjust

for ground lead.)

so that the signal amplitude is

I

Checking of erase voltage and oscillation

I

Control

I

Specification

I

Put the unit in record mode. Connect an oscilloscope across the full erase

head.

Make sure the erase voltage across the full

erase head is frequency is

1

I

or greater

or more and

I

Specification

Connect an AC

OUT (pin

Feed the audio signal shown in

AUDIO IN jack.

Make the self-recording and playback of the

signal.

Make sure that the AUDIO OUT level is as

specified. If it is out of specified value, verify

the bias current (ADJUSTMENT OF AUDIO BIAS

CURRENT below).

of EL connector).

to the AUDIO

Adjustment of audio bias current

Measuring instrument

I

Mode

I

Input signal Test point Control Specification

AC Oscilloscope

I

Record

I

Not required

0.3mVp-p)

or

TP6602(

)

the

.

I

Figure 2-8.

I

MECHANISM OPERATION FLOWCHART

l This flowchart describes the outline of the mechanism’s operation, but does not give its details. l Function of cam switch bit reading.

The on/off of cam switch is cam position switch

‘ON’

Mechanism position SW (1) input

Mechanism position

Mechanism position SW

input

L

input

H H H

H

input signals in conditions as shown in below.

SW

‘ON’ ‘ON’

H H H H

L

H

‘ON’

H

SW

‘ON‘

L I

L I L I H I

‘ON’

L

L L

I

‘OFF’

H

I

H

CASSETTE INSERTION -+ STOP

I

Turn off cassette switch.

Loading motor starts in normal

Cassette

direction and master cam clockwise.

inserting

Does cassette control clutch come off within 2.5 sec. after cassette switch has turned off?

Insert cassette.

t

I

t

End

I

I I

,

I

Cassette is ejected and loading motor stops.

t

Cassette switch turns on.

Loading motor turns in reverse direction and master cam counterclockwise.

t

(Cassette is judged caught halfway.)

n

0

I

J

1

I

1

I

Mechanism position SW (1)

position SW

Mechanism position

CAM SW

h

.

: :

. . .

,

: : : : : : :

:

: . : :

. . : :

. .

CD SW

SW

: : :

. , : :

:

. Shift zone

: : : .

:

Mechanism position SW Mechanism position SW (2) Mechanism position SW (3)

Mechanism position SW (4)

. .

: :

: : : : :

. . : :

: .

: : : :

.

: :

. .

: :

SW

input input input Input

Are start/end sensors at low level before cassette insertion?

I

Drum motor starts.

t

Pinch roller comes into contact.

Cam switch is at

Is drum

I

position.

pulse outputted?

End

NO

(Cassette LED or some judged defective.)

I

part is

Unloading

STOP

PLAY

STILL

Picture appears.

t

Is take-up reel sensor signal outputted?

PLAY

Press

key.

Set capstan motor to search speed.

t

End

Slow brake pressing

Slow brake comes into

Loading motor stops

Capstan motor stops.

End

STOP

Press STOP key.

I

Stop capstan motor.

Press

I

Pinch roller

releasing

Idler swinging

I

Release

Camswitchis;tPUposition.

,

Stop

Turn capstan motor in

reverse direction.

I

Stop

Is take-up reel sensor signal

outputted?

I

key.

roller.

motor.

to search

I

Loading motor turns in reverse direction and master

I

Unloading

I

STOP

Press

I

key.

I

STOP *CASSETTE EJECT

Cassette control clutch is engaged by pinch roller lever.

t

Cassette is ejected.

I

Brake

function

I

,

Cam switch

Stop loading motor.

I

Stop capstan motor.

Release brake solenoid and brake reel disk.

.

t

End

STOP

Press STOP key.

t

End

Tape unloading

Capstan motor turns in reverse direction

I

Cam switch is at

Stop position.

t

Cassette ejection

1

switch is on.

Stop loading motor.

Stop capstan motor.

1

Stop drum motor.

t

I

Brake latching

Tape slack

I

Loading motor turns in reverse direction and master cam

Energize brake solenoid.

Cam switch is at

Turn loading motor in normal direction.

Cam switch is at UC stop position.

Is take-up reel pu-Ire outputted?

Release brake solenoid and brake reel disk.

clock wise.

Turn capstan motor in reverse direction.

position.

Stop capstan motor in about 5 sec.

I

MECHANISM TROUBLESHOOTING

I

FAILURE(N0 TAPE WINDING)

Remove cassette controller, turn

I

REVPLAY FAILURE (MODE RELEASE)

I

Remove cassette

I

reel disk

Is

motor turning?

gear in

I--

Tape travel is presumably overloaded due to damage on tape. Damaged tape is to be out of use.

Are

and

applied ?

Replace capstan

motor.

YES

I

Check for broken solenoid lead (turn power off, disconnect check with tester).

t

Replacesolenoid.

and

I

Disconnect and reconnect

while attracted, or

broken lead)

1

Is brake shifter at PLAY (MC) position?

YES

brake shifter at

NO

Replace relay shifter.

I

Is take-up reel disk NO

pulse outputted

H

Is motor turning ?

YES

sensor.

I

Are

applied ?

and

NO

H

Disconnect and

reconnect main

WINDING FAILURE AT

UNUSUAL SOUND

IN EACH MODE

Remove cassette controller, turn power on and press PLAY key.

Is take-up normal

during playback

Press take-up reel disk by hand.)

Y

Is brake shifter at

position

YES

NO

key. (Turn

NO

Replace brake

shifter.

Insert cassette and press play and STOP keys repeatedly.

Y

Is rattling sound heard during loading/ unloading

YES

Turn power off and remove cassette controller.

Is reel disk height as

specified (using jig)

Power ON

key IN

Is unusual sound heard at

NO Press REW key and turn

take-up reel disk by hand.

Is unusual sound heard at

7

I

NO

Replace L block

assembly.

loading block)

,

Turn take-up reel disk

YES

slowly with finger. Are

take-up reel stopper and

gear rubbing each

other ?

Is unusual sound heard with capstan running

block

YES

Undo reel belt, turn take-up disk by hand and press

motor

NO

YES

J

key.

If there is no unusual sound heard again in each mode, go back to the start of routine to recheck.

I

L

and down. Is there

NO

Replace supply reel disk.

I

VCR POWER

The VCR

FLOW CHART NO. l-l

KEY-IN

Key-h Input is not received.

I

FLOW CHART NO. 1-2

I

Unplug the AC power cord. it a few minutes later.

I

IS the fuse

mother

I

Are the

normal in the VCR

Is the AT

Are the

properly connected with

Is there oscillation at pins (31) and

of

I

YES

and

line normal ?

and

YES

in the TV

lines

?

t

Does pin from the AC cord is plugged in or ALL CLEAR button is pressed and released?

the power button is pressed

to

of

to

IS

the PC

IS

the PC

of

change

L

level when

YES

1

e

level w

en

YES

-NO line normal

YES

line normal ?

YES

Is the key switch in good contact 7

I

NO

?

I

NO

I

.

Replace the fuse

Check the AT

Replace

Check pin

Check power key input to and serial dataslclocks between

in

line,

and

Check poor soldering.

and /or

of

or

and

of connector

Check Q9903.

an

I

short-circuit in the key

the set

?

.

YES

of

YES

and signal

serial clock and

I

YES

of the

YES

? YES

or

YES

and signal

serial clock and

of

when

INFRARED R/C

No operation is possible from the infrared remote control.

I

Are signals received at pin

and pin

the key is activated

Check

of serial

:eady(L).

Does the infrared remote control function ?

Is

applied at pin

remote control receiver ?

I

away from

Is there short-circuit in the key input or

Check line of serial ready

NO

1

I

NO

Check the switch contact.

Check soldering.

I

lines to input

Replace the infrared remote

control as required.

Check the

I

Check pin

Reposition the set not to be exposed to strong light.

Check key input terminals.

and switches for poor

FLOW CHART NO.

I

and

of

or

lines.

and /or

I

1

I ,

Check wire harness to mechanism.

I

CASSETTE CONTROL

A cassette tape is not taken in.

I

t

the cassette housing in shape?

I

Are the cam switch and cassette

slider properly positioned ?

I

cassette tape is inserted ?

Does of go to cassette tape is inserted ?

when the cassette tape is inserted ?

I

YES

level when the

of

YES

go to 1lV

I

FLOW CHART NO.

I

J

NO

I

J

Check the cassette switch and all .

Check the cassette housing.

I

Reposition the cam switch.

the way up to pin

Check to pin

of

I

Check

of

and all the way up

J

I

J

I

Does the capstan motor start

when the EJECT button is pressed

Does the take-up reel disk turn

when the capstan motor is

running

reel socket when theta e-up reel disk is turning ?

Is pulse at pin the take-up reel disk is turning

inputted

LOADING MOTOR AND EJECT

Acassette tape fails to eject.

t

YES

at pin

YES

of

YES

of

when

NO

ND

FLOW CHART NO.

I I

See FLOW CHART NO. l-7.

Check the reel disk and reel drive

Check the reel sensor.

Check between pin socket and all the way up to

and

Check between pin and all the way up to pin

of

A cassette tape is taken in, but ejected at once.

f

Do start/end sensors voltage at

I(8) of

. to

L

when the cassette tape is loaded ?

Does cassette switch voltage at pin

of

to

cassette tape is loaded

I

Replace

level

change from

e from

when the

Is

Is the correct voltage at the loading motor terminal ?

.

ND

I

Check the start

Check the cassette switch and all the way up to

end sensors and

Does the loading motor run?

Replace the cassette cam, gear, etc.

of

YES

NO

Check

of it.

Check between

the way up to the loading motor.

Replace the loading motor.

and

level of pin

all

18X

U

J

TAKE-UP REEL PULSE GENERATOR TROUBLESHOOTING

No reel sensor pulse appears.

I

FLOW CHART NO.

DRUM MOTOR TROUBLESHOOTING

The drum motor fails to run.

I

FLOW CHART NO.

I

NO

Check

Check between the MC socket and socket and \C880

.

and between the MC

Check the

I

line.

Is there the reel sensor pulse at pin (13) of the connector EA ?

NO

Is there the reel sensor pulse at pin (3) of the connector

Replace the reel sensor (located in the reel sensor

?

NO

YES

Check the harness

Is pulseatof

Is

H l voltage at pin

socket

Replace the drum motor.

of ME

YES

The drum motor runs only for a few seconds.

I

,

HEAD SWITCHING PULSE

No head switching pulse.

I

Is

rotating ?

Are the drum drum to pins

YES

and

signal inputted

and

of

NO

I

,

YES

FLOW CHART NO.

See FLOW CHART NO.

pulse.

,

Is drum ME socket 7

Is drum PC signal at pin

IS pulse at pin

signal at pin

YES

of

NO

Check between the ME socket

NO

Check the drum motor.

,

and pin

of

Check

DRUM SERVO TROUBLESHOOTING

FLOW CHART NO.

NO

Check pin (4) of the harness ME and the drum motor.

In

Drum servo

Is there 8MHz oscillation at ins and

mode

Is there the

,

Is there the head switching pulse at pin

Is there the drum control to pin ME?

Check and replace the drum motor.

of

not function.

3

of

YES

?

YES

e applied

oft

e harness

YES

of

NO

.

?

NO

I

amplifier circuit of

Check

and

See FLOW CHART NO. l-l

Does the drum error (pins

and

operate normally ?

NO

in

Is there the reference

YES

signal (V-sync. ) at pin

of

Check the composite sync. signal at pin (1) of connector El from Y/C

I

mode

?

NO

I

Replace IC880

Check

I

CAPSTAN SERVO TROUBLESHOOTING

Capstan servo does not function.

I

OW CHART NO.

Does

t

appear at pin 62) of

Is the harness EO-MR

normal ?

I t YES

YES

NO

Replace the harness MR.

Replace

Check

YES

Check the composite

sync. slgnal line and pin

circuit.

VCR RECORDING MODE

No record.

FLOW CHART NO.

VCR RECORDING MODE (CHROMA) TROUBLESHOOTING

Record Is In black and white ( E-E color mode

FLOW CHART NO.

I

Is there a signal at pin (32)

Is there a signal at pin (2)

of connector

Is there a signal at pin

of

Is pin level

Check cylinder.

of

YES

Are there clock signals at pins (9) and

YES

Is there a signal at pin

I

Is there a signal at pin

I I

Is there a signal at pin

J

NO

l

I

Check the BIAS line.

I

,

of

YES

of connector

YES

t ,

and

of

YES

7

NO

I L

NO

I

NORMAL

I I

Is there

Check pin CC and signal line.

I

Check the signal at pin (Frequency,

Frequency, 3.58 MHz.

of

DATA and

respectively?

at pin

YES

of connector

?

NO

and .

ABNORMAL

I-I I

Check

and peripheral circuit.

Check data and clock signals from

Check the PC

Check

peripheral circuit.

Check the

Check the CHROMA ROTARY line.

and

harness.

L

t

line.

Replace

I

VCR PLAYBACK MODE (LUMINANCE)

No Playback.

VCR PLAYBACK MODE

Playback is in black and white.

I

FLOW CHART NO. 1-16

Are there at pin

of

YES

I

YES

t

Is there a

of

I

1 ?

YES

at pin

I

I I

Are there clock signals at pins (9) and

Check

of

DATA and

respectively?

?

YES

Head

circuit of

I

YES

Check the harness from

I

the pin

level ?

YES

of

YES

I

NO

H

NO

Check data and clock

signals from

Check the PC 5V line.

GOOD

Q2202-

I

Check

I

Replace

J

signal line.

Are there clock signals at pins (9) and

I

Is there a signal at pin

of

I

Is there a

of

YES

? YES

at pin

NO

Check all the way up to pin the harness from

Check and adjust VCO

Is there signal at pin

Check the signal at pin

of

toiCE

?

of

Replace

DATA and

respectively?

YES

and

rotary

of

YES

?

,4.43

I

Check DL550 1 and Q55

(PAL),

NO

Check the

ROTARY line.

ABNORMAL

peripheral circuit.

1

and Q5513,

and

Is there a chroma signal at pin (5) of CC connector

I

Check Q230 1 and harness from

YES

EL J to

NO

I

there a signal at pin

t

of

YES

of

,

?

YES

r

Is there a signal at pin

J

NO

VCR E

E MODE

NO E-E signal.

Check the harness from

I

Is there

and

at pins

of

1 ?

AD

NO

to

EL

and input signal line.

FLOW CHART NO. 1-17

Sound is not heard >

I

Check the ‘L” level at

in

VCR SOUND

I

Is there Bias Oscillator signal at pin pin Oscillator) ?

Check the line between pin

of Head.

No Sound

But audio

of

YES

Signal

and Audio

Sound is heard

and (Bias

is not

FLOW CHART NO.

Sound is not heard

Is there an Audio Signal at pin

?

of

NO

clock signals at pins and

of

Replace

signals from

Replace

Check pin (19) of parts.

I

Signal at pin

connector?

I I

Check the

TV mother

I

YES

of

YES

and peripheral

Check Q6602,Q6601 and peripheral parts.

I

Check the Audio mute circuit;

and

(TDA7233) on the

Check the

mode.

I

level at

I

and Q6607.

TROUBLESHOOTING OF TV SECTION

I I I

.I

ii

E

Circuit to be checked:

TUNER

control

power source

NO PICTURE, NO SOUND

I

t

Does the noise level increase at max

Contrast, Brightness, and Sound Control ?

FLOW CHART

FLOW CHART NO.

NO

I

SCAN

1

Check the tuner bias.

t

I

Normal

I

I I

t

Abnormal

t

Is there a signal at pin (7) of

1

Does the 9V appear at pin (9) of

+ 6)

Is there a signal at

t

Check

and adjacent parts.

bias check.

0

check

Normal

I

bias

I

parts.

I

AND WHITE

FLOW CHART NO. 1-8

mode)

FLOW CHART NO.

I

NO SOUND

I

Circuits to be checked:

IC1801 and its

l

Output Circuit

,

NO SPECIFIC COLOUR (PAL)

Specific colours are not produced in

of

.

and at pin

there a

at pin

pin (3) of AD?

signal

Check the VCR: TROUBLE SHOOTING

No

‘RECORD IS IN

I

Check adjacent parts

and

Check speaker.

NO PLAYBACK PICTURE

I

NO PLAYBACK SOUND

FLOW CHART NO.

FLOW CHART NO. Z-7

(PAL

Check Q851 and its adjacent circuits.

The picture colour is

I

adjacent circuits

Readjust the white balance.

The picture

I

is

I

Circuits to be checked:

l IC1801 and its Adjacent

Circuit

Output Circuit

NO SPECIFIC COLOUR (SECAM)

IS there a chroma signal at pin (20) of IC1801

YES

No

and at

FLOW CHART NO. 1-9

Specific colours are not produced in

No

YES

Circuits to be checked:

l

and its Adjacent Circuit

l

8. Output Circuit NO SPECIFIC COLOUR (NTSC)

,

Specific colours are not produced in

Is there a at pin

of

and at pin

signal

pin (3) of AD?

Yes

receptron.

Check the VCR: TROUBLE SHOOTING

No

‘RECORD IS IN

FLOW CHART NO.

mode)

When change channel No does colour appear?

YES

----

Check

of connector

abnormal colour.

Check Pins

Abnormal

Signal

level at pm (9)

AG

in

t

When colour control minimum,

No

I

t

I

of

bias.

I

YES

No

I

i

Re-adjust the white balance. I

X1801 (NTSC

Check adjacent circuits.

_

1401

and its

I

adjacent circuits

I

Readjust the white balance.

Check

I

adjacent circuits.

I

and its

I

I I

MODEL

FULL ERASE HEAD

OVERALL SCHEMATIC DIAGRAM

L---_---J

I

1

I

2

I

3

I

4

I

5

I

6

I

TV MAIN

2 3 3 .

6 6

I

7

638PEZZ

7

I

8

I

9

I

MODEL VT-51

FULL ERASE HEAD

OVERALL SCHEMATIC DIAGRAM

DRUM MOTOR UN

1

I

2

I

3

I

4

I

5

I

6

7 z

4

I

7

I

4 5

I

8

I

9

I

1

MODEL

H

G

F

E

[G-DRIVE]

CHASSIS LAYOUT OF TV SECTION

I

K

H

0

I

0

cl

D

C

0

I

l

--

B

A

.

B-A ,

VIDEO IN

AUDIO IN

L

IL-

L

cl

l

I

7

AD

3

I

8

I

9

I

1

MODEL VT-51

H

G

F

CHASSIS

K

UT OF TV SECTION

E

D

C

I

r

B

I

UP

I

A

1

I

2

I

3

0

I

4

I

AU

5

0

I (VIDEO)

I

6

18X

VIDEO IN

7

J

, \

AUDIO IN

I I

.

DA

I

0

1

a

XI

I

0

1

3

0

L-l

n

AD

1

3

l

I

7

I

8

9

I

MODEL

Mother Unit

H

G

F

BLOCK DIAGRAM OF TV SECTION

E

D

C

I

PHOTO

.

A

1

I

2

I

3

I

4

I

5

I

6

I

UNIT

7

I

8

I

9

I

MODEL

Mother Unit

18X BLOCK DIAGRAM OF TV SECTION

r

t i

,-

I

1

I

2

I

3

I

4

I

5

I

6

UNIT

I

7

I

8

I

9

I

1

MODEL

BLOCK DIAGRAM OF TV SECTION

Cl CRT Socket, Power SW, R/C, Line Filter,

AN Unit

----HER,

1

I

2

I

3

I

4

I

5

,

I

6

I

VIDEO

CHROMA

JUNGLE

7

I

8

I

9

I

MODEL

CRT Socket, Power SW,

H

G

F

BLOCK DIAGRAM OF TV SECTION

R/C,

Line Filter,

AN Unit

E

D

C

B

A

-- -z

-----

E

1

2

I

3

I

4

I

5

I

6

I 1

VIDEO

CHROMA

JUNGLE

r

I

7

I

8

I

9

I

MODEL

BLOCK DIAGRAM OF TV SECTION

Sound Output Unit

H

G

F

E

D

C

B

A

1

I

2

I

3

I

4

I

5

6

DESCRIPTION OF TV SECTION

SCHEMATIC DIAGRAM

I

DISCONNECT THE AC PLUG FROM THE AC OUTLET BEFORE

REPLACE/NC PARTS.

SEMICONDUCTOR HEAT SINKS SHOULD BE REGARDED AS

POTENTIAL SHOCK HAZARDS WHEN THE CHASSIS IS OPERATING.

BE SURE TO USE GENUINE PARTS FOR SECURING THE SAFETY

AND RELIABILITY OF THE SET.

PARTS MARKED WITH FOR MAINTAINING THE SAFETY OF THE SET. REPLACE THESE PARTS WITH SPECIFIED ONES FOR

MAINTAINING THE SAFETYAND PERFORMANCE OF THE SET.

SERVICE PRECAUTION:

THE AREA ENCLOSED BY THIS LINE DIRECTLY CONNECTED

WHEN SERVICING THE AREA, CONNECT AN ISOLATING TRANSFORMER BETWEEN TV HAZARD OF ELECTRICSHOCK.

CAUTION:

This circuit diagram is original one, therefore there may be a slight difference from yours.

NOTE:

NOTICE:

VOLTAGE.

ARE IMPORTANT

BE SURE TO

IS

LINE TO ELIMINATE

NOTES:

The unit of resistance “ohm

resistors are

ohms,

M =

watt, unless otherwise

is omitted.

ohm).

no ted.

The unit of capacitance

=

is omitted.

The values in parentheses are the ones in the

mode; the values without parentheses are

the ones in the

VOLTAGE MEASUREMENT CONDITIONS:

DC voltages are measured between points

indicated and chassis ground by

AC 1

supplied to unit and

with

controls are set to normal viewing picture unless

Voltages are measured with

noted.

B&W of

signal.

WAVEFORM MEASUREMENT CONDI-

TIONS:

87.5% modulated co/our bar signal

is fed into tuner.

WAVEFORMS

MOTHER MOTHER

0

4

vp-p

MOTHER

0

9

18x

MOTHER

0

3

MOTHER

0

8

,

I

L

MOTHER

0

2

MOTHER

0

7

VP-P

.

MOTHER

0

1

MOTHER

0

6

MOTHER MOTHER MOTHER MOTHER

VP-P

. .

5

VP-P

0

MOTHER

0

MOTHER

0

MOTHER

0

CRT

0

CRT

(kt) VT-5118X

0

18X

0

CRT

0

SOLID STATE DEVICE

6 4

3

1

SIDE VIEW

BASE DIAGRAM

C E

1

BASE

COLLECTOR

BASE

L

COLLECTOR

EMITTER

0

BASE

L

COLLECTOR

EMITTER

.

0

BASE

COLLECTOR

EMITTER

0

1

9

CE

7

MODEL

SCHEMATIC DIAGRAM

Mother Unit

H

G

F

E

3

D

C

A

1

I

2

I

3

I

4

I

5

I

6

7

I

8

I

9

I

MOD

n

Mot

H

G

F

Unit-l

SCHEMATIC DIAGRAM

E

D

C

B

A

1

I

2

I

3

I

4

I

5

6

.

J

I

r

TUNER

n 3

AV UNIT

I

I I

I

7

I

8

I

9

I

MODEL

n

CRT Socket, Power SW, R/C, Line Filter,

I WEV I

SCHEMATIC DIAGRAM

AN Unit

I

--

1

I

2

I

3

I

4

I

5

I

6

,

I

7

I

8

I

9

I

MODEL

n

CRT Socket, Power SW, R/C, Line Filter,

I

SCHEMATIC DIAGRAM

AN Unit

e---v----!-l

I’

1om

I I

I

1

I

2

3

I

4

I

5

I

6

7

I

8

I

9

I

W

I

m

I

n

I

A

I

T

S-ATT

ICE

6

4

mm

I

2

+

5

TO

+

I

TO

NO74 ICE

4

,

.

T

ICE

n

Tuner

NOTE: The parts here shown are supplied as an assembly but not independently.

. . . . . . . . . .

. : : : . . . : : : . . . . . : : : . .

. .

. : : . :

. . . . . . . . . . . . . . . . . . . . . . .

I

l

Infrared Remote Control Unit

NOTE: The parts here shown are supplied as an assembly but not independently.

AFT

I

1

I

2

I

3

I

4

I

5

6

D

I

n

I

m

I

n

I

Memo

. . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..*.........

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..a.....

. . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . ..*......................................

. . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . ..*...............

. . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . ..*...........................................*

. . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . .

. . . .

. . . . . . . . .

.....................................................................................................

..............................................................................

............................................................................................

.....................................................................

..........................................................................................................................................................................

CHASSIS LAYOUT OF VCR SECTION

JACK

I

Y

LEVEL

I

ALL C

I

Y

El

I

0

I

Et

EM

I

1

I

2

I

3

I

4

I

5

6

,

W-CLIP

CLIP

DEVIATION

I

“Co

GND

0

l-l

.

PB CHROMA

HEAD SWITCHING PULSE

I

REC SIGNAL

0

I

0

ED

.

I

n

EL

I BIAS(+)

BIAS

I

0

I

9

I

cl

n

I

7

8