SHARP DVNC70, DV-NC70U, DV-NC70C, DV-NC72U. Service Manual

SERVICE MANUAL

S62K3DV-NC70U

VCR/DVD COMBINATION MODEL

DV-NC70U/C DV-NC72U

EJECT/STOP

POWER

PLAY

REW

AV 2 IN

VIDEO

L(MONO)-AUDIO-R

REC

VCR/DVD SELECTOR

TIMER

VCR DVD

STOP

OPEN/CLOSE

PLAY

D V-NC70C

D V-NC70U

MODELS

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 be used.

CONTENTS

1. IMPORTANT SERVICE NOTES........................................................................................................ 2

2. FEATURES........................................................................................................................................ 4

3. SPECIFICATIONS ............................................................................................................................. 4

4. PART NAMES.................................................................................................................................... 6

5. MAINTENANCE CHECK ITEMS AND EXECUTION TIME ............................................................... 9

6. DISASSEMBLY METHOD ............................................................................................................... 10

7. OPERATION OF PICKUP ............................................................................................................... 14

8. ADJUSTMENT, REPLACEMENT AND ASSEMBLY OF MECHANICAL UNITS ............................ 15

9. TEST MODE .................................................................................................................................... 38

10. TROUBLESHOOTING..................................................................................................................... 41

11. BLOCK DIAGRAMS......................................................................................................................... 52

12. SCHEMATIC DIAGRAMS................................................................................................................ 60

13. PRINTED WIRING BOARD ASSEMBLIES ..................................................................................... 74

14. REPLACEMENT PARTS LIST ........................................................................................................ 89

15. PACKING OF THE SET................................................................................................................. 106

D V-NC72U

Page

SHARP CORPORATION

This document has been published to be used for after sales service only. The contents are subject to change without notice.

DV-NC70U/C DV-NC72U

1. IMPORTANT SERVICE NOTES

BEFORE RETURNING THE VCR/DVD COMBINATION MODEL

Before returning the video cassette recorder to the user, perform the following safety checks.

1. 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 VCR/DVD combination model.

2. Inspect all protective devices such as non-metallic control knobs, insulation materials, cabinet backs, adjustment and compartment covers or shields, isolation resistor/capacitor networks, mechanical insulators etc.

3. To be sure that no shock hazard exists, check for current in the following manner.

● Plug the AC line cord directly into a 120 volt AC outlet (Do not use an isolation transformer for this test).

● Using two clip leads, connect a 1.5k ohm, 10 watt resistor paralleled by a 0.15µF capacitor in series with all exposed metal cabinet parts and a known earth ground, such as a water pipe or conduit.

● Use an SSVM or VOM with 1000 ohm per volt, or higher, sensitivity or measure the AC voltage drop across the resistor (See Diagram).

● Move the resistor connection to earth exposed metal part having a return path to the chassis (antenna, metal cabinet, screw heads, knobs and control shafts,

etc.) and measure the AC voltage drop across the resistor. Reverse the AC plug on the set and repeat AC voltage measurements for each exposed part. Any reading of 0.45V rms (this corresponds to 0.3mA rms AC.) or more is excessive and indicates a potential shock hazard which must be corrected before returning the VCR/DVD combination model to the owner.

SSVM

AC SCALE

1.5k ohms. 10W

0.15 µF

TEST PROBE

TO EXPOSED METAL PARTS

CONNECT TO KNOWN EARTH GROUND

WARNING :TO REDUCE THE RISK OF FIRE OR ELEC-

TRIC SHOCK, DO NOT EXPOSE THIS APPLIANCE TO RAIN OR MOISTURE.

CAUTION

RISK OF ELECTRIC SHOCK

DO NOT OPEN

CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK. DO

CAUTION:

3.0A 125V

NOT REMOVE COVER. NO USER-SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.

This symbol warns the user of uninsulated voltage within the unit that can cause dangerous electric shocks.

This symbol alerts the user that there are important operating and maintenance instructions in the literature accompanying this unit.

This symbol mark means fast operating fuse. For continued protection against risk of fire, replace only with same type fuse F901 (3.0A, 125V).

1. NOTES DE SERVICE IMPORTANTES

AVANT DE RENDRE LE VCR/DVD MAGNETOSCOPE Avant de rendre le magnétoscope à l’utilisateur, effectuer

les vérifications de sécurité suivantes.

1. Vérifier toutes les gaines de fil pour être sûr que les fils ne sont pas pincés ou que le matériel n’est pas coincé entre le châssis et les autres pièces métalliques dans le VCR/DVD magnétoscope.

2. Vérifier tous les dispositifs de protection tels que les boutons de commande non métalliques, les matériaux d’isolement, le dos du coffret, les couvercles de compartiment et ajustement ou les boucliers, les réseaux de résistance / condensateur d’isolement, Ies isolateurs mécaniques, etc.

3. Pour être sûr qu’il n’y a aucun risque de choc électrique, vérifier le courant de fuite de la maniére suivante.

● Brancher le cordon d’alimentation secteur directement dans une prise de courant de 120 volts. (Ne pas utiliser de transformateur d’isolement pour cet essai).

● Utiliser deux fils à pinces et connecter une résistance de 10 watts 1,5 kohm en parallèle avec un condensateur de 0,15 µF en série avec des pièces du coffret métallique exposées et une masse de terre connue telle qu’un tuyau ou un conduit d’eau.

● Utiliser un VTVM ou VOM avec une sensibilité de 1000 ohms par volt ou plus ou mesurer la chute de tension CA entre la résistance (voir diagramme).

● Déposer la connexion de la résistance à toutes les

pièces métalliques exposées ayant un parcours de retour au châssis (connexions d’antenne, coffret métallique, tétes de vis, boutons et arbres de commande, etc.) et mesurer la chute de tension CA entre la résistance. Inverser la fiche CA (une fiche intermédiaire non polarisée doit être utilisée à seule fin de faire ces vérifications.) sur l’appareil et répéter les mesures de tension CA pour chaque piéce métallique exposée. Toute lecture de 0,45 Vrms (ceci correspond à 0,3 mArms CA) ou plus est excessive et signale un danger de choc qui doit être corrigé avant de rendre le VCR/DVD magnétoscope à son utilisateur.

VTVM

ECHELLE CA

1,5 KOHMS

10W

0,15 µF

SONDE D'ESSAI

VERS PIECES METALLIQUES EXPOSEES

CANNECTER A UNE MASSE DE TERRE CONNUE

DV-NC70U/C DV-NC72U

ATTENTION: POUR REDUIRE LES RESQUES D'IN-

CENDIE OU DE CHOC ELECTRIQUE, NE PAS EXPOSER CET APPAREIL A LA PLUIE OU A L'HUMIDITE.

ATTENTION

RISQUE DE CHOC ELECTRIQUE

ATTENTION: AFIN DE REDUIRE LES RISQUES DE CHOC

ELECTRIQUE, NE PAS RETIRER LE COUVERCLE, AUCUN ORGANE INTERNE NE PEUT ETRE REPARE PAR L'UTILISATEUR. CONFIER L'APPAREIL A UN DEPANNEUR QUALIFIE.

Ce symbole signale à l'utilisateur la présence d'une tension non isolée à l'intérieur de l'appareil qui peut être la cause de secousses électriques dangereuses.

Ce symbole avertit l'utilisateur que des instructions importantes relatives à l'utilisation et àl'entretien se trouvent dans le manuel accompagnant l'appareil.

PRECAUTION:

Cette marque indique le fusible à action in stantansée. Pour la protection continue contre le risque d'incendie,

3,0A 125V

ne remplacer que par le fusible type F901 (3,0A, 125V).

NE PAS OUVRIR

DV-NC70U/C DV-NC72U

2. FEATURES

ËË

Ë Common Features

ËË

• A DVD, CD player and VCR all in one.

• Simultaneous VCR recording and DVD playback.

ËË

Ë VCR

ËË

• Hi-Fi Stereo Sound/Double-Azimuth 4-Heads

• Built-in MTS (Multi-channel TV Sound) Decoder

• 400 Times Rewind Speed to Fast Forward and Rewind.

• EZ Set Up (Auto Channel/Clock Set Up)

• S-VHS Quasi Playback

• 19µ Clear Picture System (in EP mode)

• Simple Recording Timer

• Sharp Super Picture

• Exact Rec/Tape Remaining

ËË

Ë DVD

ËË

• Plays DVD, CD (Digital Audio) discs as well as CD-R/CD-RW discs recorded in MP3 file format

• 3D Virtual Surround provides high-quality surround sound

• Digital Gamma correction and Digital Super Picture functions

• Dolby Digital*1/DTS*2 digital out capability

• High-quality digital images

• High-quality digital sound

*1Manufactured under license from Dolby Laboratories. "Dolby", "Pro Logic" and the double-D symbol are

trademarks of Dolby Laboratories.

*2"DTS" and "DTS Digital Surround" are trademarks of Digital Theater Systems, Inc.

3. SPECIFICATIONS

Signal System NTSC

INPUT/OUTPUT JACKS

DVD/VCR shared output jacks VIDEO jack: RCA Pin-jack

AUDIO jack: RCA Pin-jack

DVD output jacks VIDEO jack: S-Video jack

Component Y jack: RCA Pin-jack Component PB jack: RCA Pin-jack Component PR jack: RCA Pin-jack AUDIO jack: RCA Pin-jack DIGITAL AUDIO IF: Coaxial digital AUDIO output jack: RCA Pin-jack

VIDEO input jacks VIDEO jack: RCA Pin-jack

AUDIO jack: RCA Pin-jack

VCR

Video Recording System Rotary Two-Head Helical Scanning

Number of Video Heads 4

Video Signal Standard NTSC Color System

Audio Recording System 1 Stationary Head for Linear Audio

2 Rotary Heads for Hi-Fi stereo

Tape Width 12.7 mm (1/2 inch)

Tape Speed (SP) 33.35 mm/sec. (1.31 i.p.s.)

(LP) 16.67 mm/sec. (0.66 i.p.s.) (playback only) (EP) 11.12 mm/sec. (0.44 i.p.s.)

Maximum Recording Time (SP) 160 min. (T-160)

(EP) 480 min. (T-160)

Channel Coverage VHF 2-13

UHF 14-69 CATV 1-125

Antenna Input 75Ω

Video Input Input level: 0.5 to 2.0 Vp-p (75Ω) Video Output Output level: 1.0 Vp-p (75Ω) Audio Output Input level: –8 dBs (47kΩ)

(0 dB = 0.775 Vrms)

Audio Output Output level: –8 dBs (1kΩ)

(0 dB = 0.775 Vrms)

Hi-Fi Audio Dynamic Range: 90 dB

Frequency Response: 20 Hz-20 kHz

Memory Backup 60 seconds

DVD

DVD/VCR shared Video output Output level: 1 Vp-p (75Ω)

Component color output Y output level: 1 Vp-p (75Ω)

PB output level: 0.525 Vp-p (75Ω)/75% color PR output level: 0.525 Vp-p (75Ω)/75% color

S video output Y output level: 1 Vp-p (75Ω)

C output level: 0.286 Vp-p (75Ω)

Audio output Output level: 2 Vrms (1 kHz, 0 dB)

Video signal horizontal resolution 500 lines

S/N ratio 60 dB

Audio signal frequency characteristics For DVD linear PCM playback:

4 Hz to 22 kHz (48 kHz sampling) 4 Hz to 44 kHz (96 kHz sampling) CD playback: 4 Hz to 20 kHz (EIAJ)

S/N ratio CD: 100 dB, 1 kHz (EIAJ)

Dynamic range DVD linear PCM: 96 dB (EIAJ)

CD: 96 dB (EIAJ)

Total harmonic distortion ratio CD: 0.006%

Pickup Wave length: 650 nm

Laser output: Max. 0.7 mW

DV-NC70U/C DV-NC72U

Operating temperature 5 °C to 35 °C (41 °F to 95 °F)

Storage temperature –20 °C to 55 °C (–4 °F to 131 °F)

Power supply 120 V AC, 60 Hz

Power consumption 28 W

Dimensions 430 mm × 93.5 mm × 356 mm (W × H × D)

(including attachments) (16 15/16" × 3 11/16" × 14 1/32")

Weight 4.8 kg (10.6 lbs)

Specifications are subject to change without notice. Weight and dimensions are approximate.

3-1. ACCESSORIES

Accessories: Remote control unit × 1, "AA" size battery (R-6, UM/SUM-3) × 2,

VIDEO/AUDIO cable × 1, Round coaxial cable (75 Ohm, 1 m [3-1/4 ft.]) × 1

DV-NC70U/C

VCR Main Unit (Front)

OPEN/CLOSE

POWER

EJECT/STOP

REW

PLAY

REC

VCR/DVD

SELECTOR

TIMER

VCR DVD

PLAY

STOP

AV 2 IN

VIDEO

(

MONO

AUDIO

SEP

VCR

VCR/DVD SELECTOR

POWER

REC

Clock Indicator

Channel Indicator

Tape Counter Indicator

PLAY

Front AUDIO/

VIDEO input

jack

Timer Recording

Indicator

Tape Speeds

Indicator

VCR Mode

Indicator

Operation status

Indicator

Cassette compartment

EJECT/STOP

REW

TIMER indicator

Audio Output

Indicator

VCR Front Panel Display

DVD Main Unit (Front)

DVD Front Panel Display

OPEN/CLOSE

POWER

EJECT/STOP

REW

PLAY

REC

VCR/DVD

SELECTOR

TIMER

VCR DVD

PLAY

STOP

AV 2 IN

VIDEO

(

MONO

AUDIO

Disc tray

OPEN/CLOSE

POWER

TITLE

indicator

Operation status/Time indicator

TRACK

indicator

CHAPTER

indicator

Disc operation

buttons (PLAY, STOP)

PROGRAM indicator

REPEAT indicator

ANGLE indicator

VIRTUAL surround

indicator

VCR/DVD SELECTOR

VCR DVD indicator

You can toggle between 1 and 2 by

pressing the remote control unit’s

DISPLAY button.

DV-NC72U

4. PART NAMES

DV-NC70U/C

Main Unit (Rear)

VCR

IN FROM

ANTENNA

UHF/VHF

CATV

OUT TO TV

AV 1 IN

AUDIO

(MONO)

VIDEO

AUDIO

VIDEO

DVD/VCR

OUT

DVD OUT

DIGITAL

AUDIO

S-VIDEO

COMPONENT

VCR

IN FROM

ANTENNA

UHF/VHF

CATV

OUT TO TV

AV 1 IN

AUDIO

(MONO)

VIDEO

AUDIO

VIDEO

DVD/VCR

OUT

DVD OUT

DIGITAL

AUDIO

S-VIDEO

COMPONENT

VCR AUDIO input

jacks

ANTENNA IN (antenna

or cable input)

VCR VIDEO input

jack

ANTENNA OUT

DVD/VCR shared

AUDIO output jacks

DVD Coaxial DIGITAL

output jack

DVD S-VIDEO output jack

DVD AUDIO output jacks

DVD/VCR shared

VIDEO output jack

COMPONENT VIDEO output jacks

To an AC outlet

DV-NC72U

DV-NC70U/C

REV FWD

PLAY

STOP

100

OPEN/

VCR/DVD

SELECTOR

VCR MENU

DVD SETUP

TAPE

SPEED

SCREEN

TITLE

DVD MENU

DISPLAY

FUNCTION

CONTROL

PROGRAM ANGLE

CANCEL

RETURN

POWER

TIMER

ON/OFF

TV/ VCR EJECT

SET

ENTER

ZERO BACK

SKIP SEARCH

REPLAY

VCR DVDAM/PM INPUT

PAUSE/STILL

REC

SLOW

VCR DVD

SKIP

DPSS

AUDIO

OUTPUT

VCR/DVD COMBINATION

ON SCREEN

TIMER ON/OFF

POWER

DISPLAY

CANCEL

CURSOR ( / / / )

Number buttons

100, AM/PM

PLAY

REW

REC

STOP

TAPE SPEED

VCR/DVD CHANGE Switch

TV/VCR

VCR/DVD SELECTOR

EJECT

VCR MENU

SET

ZERO BACK

SKIP SEARCH

REPLAY

VCR DVD

PAUSE/STILL

SLOW

—

, DPSS

—

INPUT

SLOW

AUDIO OUTPUT

CH /

Remote Control Unit (VCR Operation Buttons)

The explanations on this page use the VCR/DVD CHANGE Switch in the VCR position.

Do not subject the remote control unit to shock, water or excessive humidity.

The remote control unit may not function if the product’s sensor is in direct sunlight or any other strong light.

Incorrect use of batteries may cause them to leak or burst. Read the battery warnings and use the batteries properly.

Do not mix old and new batteries, or mix brands in use.

Remove the batteries if you do not use the remote control unit for an extended period of time.

Remote Control Unit (DVD Operation Buttons)

The explanations on this page use the VCR/DVD CHANGE Switch in the DVD position.

REV FWD

PLAY

STOP

100

OPEN/

VCR/DVD

SELECTOR

VCR MENU

DVD SETUP

TAPE

SPEED

SCREEN

TITLE

DVD MENU

DISPLAY

FUNCTION

CONTROL

PROGRAM ANGLE

CANCEL

RETURN

POWER

TIMER

ON/OFF

TV/ VCR EJECT

SET

ENTER

ZERO BACK

SKIP SEARCH

REPLAY

VCR DVDAM/PM INPUT

PAUSE/STILL

REC

SLOW

VCR DVD

SKIP

DPSS

AUDIO

OUTPUT

VCR/DVD COMBINATION

ON SCREEN

POWER

DISPLAY

FUNCTION CONTROL

RETURN

TITLE

CURSOR ( / / / )

Number buttons

REV

STOP

VCR/DVD SELECTOR

REPEAT, PROGRAM

ANGLE

PLAY

DVD MENU

OPEN/CLOSE

DVD SETUP

ENTER

PAUSE/STILL

FWD

SLOW

VCR/DVD CHANGE Switch

SKIP

DV-NC72U

5. MAINTENANCE CHECK ITEMS AND EXECUTION TIME

MECHANICAL PARTS REGUIRING PERIODICAL INSPECTION

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

DV-NC70U/C DV-NC72U

Parts

Pickup Spindle Unit Sled Motor Loading Motor Belt

Note : Part Replacement

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

Maintained

1,000 hrs.

2,000 hrs.

CARES WHEN USING THE PICKUP

1. The laser light having wavelength 650 nm is emitted from the objective lens. BE CAREFUL SO THAT THE LASER LIGHT DOES NOT ENTER DIRECTLY INTO YOUR EYE.

2. The semiconductor laser may be easily damaged by electrostatic charges. When handling the pickup, take care so that the electrostatic charge is not generated.

3. The semiconductor laser may be easily damaged by overcurrent. Use the power supply unit which does not give any spike current when the power is turned on and off.

4. Carefully remove the dust and dirt from the objective lens with the lens blower. When handling the objective lens, take due care so that it is not contaminated with fingerprint, etc. If the objective lens is contaminated, impregnate the cleaning paper with a small quantity of solvent (isopropyl alcohol), and gently wipe to clean.

5. The ozone layer depleting components (ODC) are not used in the production process for the product.

DV-NC70U/C

DV-NC72U

6. DISASSEMBLY METHOD

6-1. DISASSEMBLY METHOD

1)Removing the cabinet. (1) Remove the four screws 1 and one screw 2.

2)Removing the front panel. (1) Remove the two screws 3. (2) Release the six hooks 4.

3)Removing the front PWB. (1) Release the one hook 5 and tilt the PWB

toward you to remove it.

(2) Release the one hook 6 and tilt the PWB

toward you to remove it.

4)Removing the DVD mechanism. (1) Remove the four screws 7 to remove the DVD REINF.

angle. (2) Remove the two screws 8 and two screws 9. (3) Remove the two screws 0 to remove the Angle (DVD) .

(4) Remove the DVD Shield (lower) q. (5) Remove the four screws w to remove the DVD Main PWB

Unit from Angle (DVD).

(6) Remove the two screws e to remove the Power PWB

Unit.

DV-NC70U/C DV-NC72U

5)Removing the Cassette Housing Control/VCR Mechanism. (1) Remove the two screws r. (2) Remove the one screw t. (3) Remove the two screws y.

6)Removing the Antenna Terminal Cover/VCR Main PWB Unit.

(1) Remove the six screws u. (2) Remove the two screws i. (3) Remove the one screw o.

7)Removing the Bottom Plate.

(1) Remove the one screw p.

DV-NC70U/C DV-NC72U

6-2. EXTENSION CABLE USE POINT (ONE PLACE)

Parts Code Price Code Name/Description

QCNW-8571GEZZ AN Extension cable (wire), 9pin 500mm

DVD Main CN3201–Power CN201

Extension Cable Diagram

Tuner

Power PWB

VCR Main PWB

VCR Mechanism

F-AV PWB VCR/DVD Display PWB

CN201

QCNW-8571GEZZ 9 pin

DVD Mechanism

CN3201

DVD Main PWB

DV-NC70U/C DV-NC72U

6-3. REPLACEMENT OF MAIN PARTS

1. Remove the mechanism with angle from the set. (refer to 33 on page 104. Remove K , M , N )

2. It is in such cases as the thin driver, and it is pushed in slowly, and a tray is drawn in the arrow direction the Slide Rack on the left of the base chassis.

3. Take out disk.

Front Side

1. After setting the mechanism chassis to the angle state, ground it to prevent the electrostatic discharge damage of the pickup.

2. Remove the DVD Shield (lower) 40 (refer to the illustration on page 104).

3. Remove P , Q from the DVD Main PWB Unit 27 . (Pickup Relay FFC 58 isn't removed.) (refer to the illustration on page 104)

4. Remove screws fixing the base chassis (located at the back right and at front left when facing the set).

5. With the Pickup FFC connected, turn over the base chassis and short (solder) two short lands on the pickup interface PWB in order to prevent the electrostatic discharge damage of the pickup.

6. Remove the Pickup FFC from the Main PWB.

7. Remove the Pickup FFC from the Pickup Interface PWB.

8. Remove the Traverse Fixing Screws to remove the Traverse Chassis ass'y.

Note: After assembling and wiring, remove the solder joint of the short land. If short-circuited, a disk is not played back.

Pickup FFC

Traverse Fixing Screw

Sled Motor Lead Wire

Loading Motor Lead Wire

Since the Pickup optical axis and turntable inclination of DVD are adjusted with higher accuracy, make a replacement as a mechanism service chassis ass'y.

Pickup Interface PWB

Pickup FFC

Short Land

DV-NC70U/C

2-focus objective lens

Actuator assembly

DV-NC72U

7. OPERATION OF PICKUP

7-1. CIRCUIT CONFIGURATION OF PICKUP

The pickup unit reads signals from the disk, and the flexible cable is connected to the board. The following signals flow through the cable.

7-2. EQUIVALENT CIRCUIT OF PICKUP

FO+ TR– TR+

OSC

FO–

LD PD VA

–

ref

GND

Power adjust

ACTUATOR

HIGH-FREQUENCY CONVOLUTION

HOLOGRAM LASER UNIT

TR–

FO+

TR+

FO–

GND

(NC)

GND

ref

GND

7-3. POLARITIES OF SIGNAL

Focus When electric current is flowed

FO+, FO- from FO+ to FO-, the lens comes

to near the disk.

Tracking When electric current is flowed

TR+, TR- from TR+ to TR-, the lens goes

toward the outer circumference.

(VCC/2)

7-4. SIGNALS OF PICKUP

7-4-1. Tracking drive signal (TR+, TR-)

The signal drives the tracking servo mechanism which projects the beam on the track by moving the objective lens (OL) to the outer or inner circumference (at a right angle against the track) of the disk.

7-4-2. Focus drive signal (FO+, FO-)

The signal drives the focus servo mechanism which aligns the focus on the pit of the disk by elevating OL (vertically against the disk surface.)

The VR terminal is connected to GND.

7-4-3. Monitor Diode (PD)

Since the laser diode largely varies output of the laser light even if the flowing current is slightly varied, the projection light is detected with the monitor diode to control the laser light to be equally output. Since the current varies on the monitor diode according to the intensity of the received light of the laser diode, the drive current of the laser diode is reduced if the current of the monitor diode increases. On the contrary, the drive current of the laser diode is increased if the current of the monitor diode decreases. As the projection light of the laser diode becomes stronger, the current of the monitor diode increases to increase the current which flows into the monitor diode output (PD). This is input to the pin 44 of IC301 and is compared with the reference voltage to control the drive current of the laser diode. The circuit is called ALPC (Automatic Laser Power Control).

When the quantity of laser light increases, the current shown in figure increases and the PD terminal voltage rises.

7-4-4. Laser diode drive current control (LD)

Power supply to drive the laser diode

IC301 is used to control. The LD terminal voltage lowers, and the quantity of light reduces. (IC301 is actuated by voltage input.)

7-4-5. High-frequency convolution module power supply (VOSC)

The high-frequency convolution imposes the high-frequency signal on the DC current to impose the high frequency on the drive current of the laser. Thus, the interference of outgoing light and reflected light is prevented.

7-4-6. HF Signal (VA, VB, VC, VD)

Signals recorded in the disk

DV-NC70U/C DV-NC72U

8. ADJUSTMENT, REPLACEMENT AND ASSEMBLY OF MECHANICAL UNITS

The explanation given below relates to the on-site general service (field service) but it does not relates to the adjustment and replacement which need high-grade equipment, jigs and skill. For example, the drum assembling, replacement and adjustment service must be performed by the person who have finished the technical courses.

8-1 MECHANISM CONFIRMATION ADJUSTMENT JIG

So as to perform completely the mechanism adjustment prepare the following special jigs. So as to maintain the initial performance of the machine the maintenance and check are necessary. Utmost care must be taken so that the tape is not damaged. If adjustment needs any jig, be sure to use the required jig.

No. Jig ltem Part No. Code Configuration Remarks

This cassette torque meter is used for check-

1. Torque Cassette Meter JiGVHT-063 CZ

JiGTG0090 CM

Torque Gauge

JiGTG1200 CN

3. Torque Gauge Head JiGTH0006 AW

ing and adjusting the torque of take-up for measuring tape back tension.

These Jigs are used for checking and adjusting the torque of take-up and supply reel disks.

4. Torque Driver JiGTD1200 CB

Master Plane Jig and Reel Disk Height

5. Adjusting Jig

JiGRH0002 BR JiGMP0001 BY JiGSG2000 BS

Tension Gauge

6. JiGSG0300 BF

Pinch pressing force

7. JiGADP003 BK

measuring jig

Alignment Tape

VROATSV CD

VROEFZCS BG

VROEFZHS BH

Guide roller height

adjustment driver

X value adjustment

10. JiGDRiVER-6 BM

gear driver Tension Pole

11. Adjustment Driver

JiGDRiVERH-4

JiGHMEC-M005 CK

When fixing any part to the threaded hole using resin with screw, use the jig. (Specified torque 5 kg)

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

There are two gauges used for the tension measurements, 300 g and

2.0 kg. This Jig is used with the tension

gauge. Rotary transformer clearance adjusting jig.

These tapes are especially used for electrical fine adjustment.

Video Audio HiFi Audio Track 525 Monoscope 7k — 58µm NTSC Color Bar 1k — 58µm

Black Level (only SYNC) signal

This screwdriver is used for adjusting the guide roller height.

For X value adjustment

—19µm

2.3k

This Jig is used for adjustment of tension pole.

DV-NC70U/C DV-NC72U

8-2 MAINTENANCE CHECK ITEMS AND EXECUTION TIME

Perform the maintenance with the regular intervals as follows so as to maintain the quality of machine.

Possible symptom

encountered

Abnormal rotation or significant vibration requires replacement.

Parts

Guide roller ass’y

Maintained

500 hrs.

1000 hrs.

1500 hrs.

2000 hrs.

Remarks

Sup guide shaft Reverse guide Slant pole on pole base Full erase head A/C head

Upper and lower drum ass’y

Capstan D.D. motor Pinch roller

Reel belt

Tension band ass’y Loading motor

Idler ass’y Limiter pulley

Lateral noises Head occasionally blocked

Color and beating Small sound or sound

distortion Poor S/N ratio, no color

Poor flatness of the envelope with alignment tape

No tape running, uneven color

No tape running, tape slack

No tape running, tape slack, no fast forward/ rewind motion

Screen swaying Cassette not loaded or

unloaded No tape running, tape

slack

Clean tape contact part with the specified cleaning liquid.

Clean tape contact area with the specified cleaning liquid.

Clean rubber and rubber contact area with the specified cleaning liquid.

Supply/take-up main brake levers

Tape slack

NOTE : Part replacement. : Cleaning : Apply grease <Specified> Cleaning liquid Industrial ethyl alcohol

* This mechanism does not need electric adjustment with variable resistor. Check parts. If any deviation is found,

clean or replace parts.

Video head cleaning procedure

1. Apply one drop of cleaning liquid to the cleaning paper with the baby oiler.

2. Gently press the cleaning paper against the video head to fix your finger, and move the upper drum so that each head is passed to and fro 5 times (do not move the cleaning paper).

3. Wipe with the dry cleaning paper.

Notes :

• Use the commercially available ethanol of Class 1 as cleaning liquid.

• Since the video head may be damaged, do not move up and down the cleaning paper.

Gently press the cleaning paper to fix with your finger, and rotate the upper drum to clean. Move to and fro 5 times for each head. (Do not move the cleaning paper.)

Rotate the upper drum with one hand.

• Whenever the video head is cleaned, replace the cleaning paper.

• Do not apply this procedure for the parts other than the video head.

Parts Code Description Code ZPAPRA56-001E Cleaning Paper AW ZOiLR-02-24TE Babe Oiler (Spoit) AH

8-3. FUNCTION OF MAJOR MECHANICAL PARTS (TOP VIEW)



DV-NC70U/C DV-NC72U



15 26

No. Function

1 Full erase head 2 Supply pole base ass’y 3 Tension arm 4 Idler wheel ass’y 5 Open guide 6 Supply reel disk 7 Supply main brake



No. Function

11 Reverse guide lever ass’y 12 Reel relay gear 13 Take-up reel disk 14 Pinch roller lever ass’y 15 Drum ass'y 16 Loading motor block 17 Drum driver motor

8 Take-up main brake 9 Pinch drive cam

10 A/C head ass’y

18 Take-up pole base ass'y 26 Auto head cleaner Ass'y

DV-NC70U/C



DV-NC72U

FUNCTION OF MAJOR MECHANICAL PARTS (BOTTOM VIEW)



No. Function



No. Function

19 Syncro Gear 20 Master cam 21 Capstan D.D. motor 22 Reel belt

23 Clutch lever 24 Limiter pulley ass’y 25 Shifter

PinchDrive Cam

Synchro Gear

Master cam

Main Chassis

Drive Lever

8-4. DISASSEMBLY AND REASSEMBLY

Cassette Control Housing

Mechanism Chassis

Main PWB

8-4-1 DISASSEMBLING THE MECHANISM

DV-NC70U/C DV-NC72U

1. When removing the mechanism from the set. Remove the two screws 1 which connecting mechanism and main frame. Take out vertically the mechanism so that it does not damage the adjacent parts.

2. Removing the mechanism and cassette housing. Remove the two screws 2 fixing the cassette housing to the mechanism, and remove the cassette housing.

8-4-2 CARES WHEN REASSEMBLING

INSTALLING THE CASSETTE HOUSING

When the cassette housing is installed on the mechanism, the initial setting is essential condition. There are two initial setting methods, namely electrical and mechanical.

1. Electrical initial setting

So as to perform initial setting of mechanism execute the Step 1 of Installation of cassette housing. After ascertaining the return to the initial setting position install the cassette housing. (Conditions: When mechanism and PWB have been installed)

DV-NC70U/C

r

DV-NC72U

2. Mechanical initial setting

• Rotate the worm gear by pushing the flange manually until return to initial position.

• When apply power supply to rotate the loading motor, please remove/unsolder at least one terminal wire.

• If voltage applied to loading motor without disconnecting the terminal wire, there is a possibility the capstan motor IC will damage.

• The maximum applied voltage is 9V. If more than 9V, there is a possibility the mechanism will damage.

• After ascertaining the return to the initial set position install the cassette housing in the specified position. (This method is applied only for the mechanism.)

Rotate the flange of worm gear by using thin stick. CW ----Loading direction CCW -- Ejection direction

Note

Be careful not to damage the gear of worm gear and worm wheel gear. It might cause a strange sound.

INSTALLING THE MECHANISM ON PWB

Lower vertically the mechanism, paying attention to the mechanism edge mode SW position, (Set the mode SW position to 270° and make sure the master cam position hole also in 270° position) and install the mechanism with due care so that the parts are not damaged. * Please make sure to insert correctly.

If not, strange moving will occur and will couse mecha-

nism damage.

EndSensor

RECTipSW

PARTS WHICH NEED PARTICULAR CARE

When installing the mechanism chassis on the PWB unit, take care so as to prevent deformation due to contact of mechanism chassis with REC Tip SW.

AEConnector

Start Sensor

ConnectorforR/T

Connectorfor CapstanMotor

Connectorfo ACHead

Master Cam Position

This positioning hole should be at frontside.

MODE SW

180°

90°

270°

0°

This pin should be at frontside.

DV-NC70U/C DV-NC72U

8-5 REMOVING AND INSTALLING THE CAS-

SETTE HOUSING

• Removal

1. In the cassette removing mode, remove the cassette.

2. Unplug the power cord.

3. Remove in the following numerical order. a) Remove two screws 1. b) Pull and circle the drive lever and pull up the cassette

housing control.

Notes

1. In the case when you use the magnet screw driver, never approach the magnet driver to the A/C head, FE head, and drum.

2. When installing or removing, take care so that the cassette housing control and tool do not contact the guide pin or drum.

3. After installing the cassette housing control once perform cassette loading operation.

8-6 TO RUN A TAPE WITHOUT THE CASSETTE

HOUSING CONTROL ASSEMBLY

1. Remove the full-surface panel.

2. Short-circuit between TP803 and TP802.

3. Plug in the power cord.

4. Turn off the power switch.

(The pole bases move into U.L.position.)

5. Open the lid of a cassette tape by hand.

6. Hold the lid with two pieces of vinyl tape.

7. Set the cassette tape in the mechanism chassis.

8. Stabilize the cassette tape with a weight (500g) to

prevent floating.

9. Turn on the power switch.

10. Perform running test.

Figure 8-1.

• Reassembly

1. Before installing the cassette housing control, shortcircuit between TP803 and TP802 provided at main PWB, press the eject button. The master cam turns and stop in eject position. Fit the drive lever to master cam through main chassis, push down and slide the drive lever towards to master cam.

*Eject position: Pinch Drive Cam positioning hole parallel to center of Synchro Gear (Synchro gear marking line). Synchro Gear positioning mark parallel to center of master cam.

2. Install in the reverse order of removal.

Pinch Drive Cam

Synchro Gear

Master cam

Main chassis

Phase matching

Hole of Pinch drive cam.

Line of synchro gear.

Master cam

500g

Mechanism chassis

Weight to prevent float (500g)

Figure 8-3.

Note:

The weight should not be more than 500g.

To take out the cassette tape.

1. Turn off the power switch.

2. Take out the cassette tape.

Drive Lever

From top view

From Bottom View

Figure 8-2.

DV-NC70U/C DV-NC72U

8-7 REEL DISK REPLACEMENT AND HEIGHT

CHECK

• Removal

1. Remove the cassette housing control assembly.

2. Remove the Supply/Take-up main brake ass'y.

3. Remove tension band from the tension arm ass'y.

4. Remove the reel disk.

Note:

Take care so that the tension band ass'y and main brake ass'y are not deformed.

Tension arm ass'y

Ten

Supply main brake

Tension band ass'y

• Reassembly (Supply reel disk)

1. Clean the reel disk shaft and apply grease (SC-141) to it.

2. Match the phases of reel disk and reel relay gear, and set the new reel disk.

3. After checking the reel disk height, wind the tension band ass'y around the reel disk, and hook to tension arm ass'y.

4. Assemble the Supply main brake ass'y.

Take-up main brake ass'y

Take-up reel diskSupply reel disk

Figure 8-4.

Notes:

1. When installing the reel disk, take due care so that the tension band ass'y is not deformed and grease does no adhere.

2. Do not damage the Supply main brake ass'y. Be careful so that grease does not adhere to the brake surface.

• Reassembly (Take-up reel disk)

1. Clean the reel disk shaft and apply grease (SC-141) to it.

2. Align the phase of the reel disk to that of the reel relay gear and to install a new take-up reel disk onto the shaft.

3. Check the reel disk height and assemble the take-up main brake ass'y.

Notes:

1. Take care so that the Take-up main brake ass'y is not damaged. Take care so that grease does not adhere the brake surface.

2. After reassembly, check the video search rewind back tension (see 8-12), and check the brake torque (see 8-

16 ).

• Height checking and adjustment Notes:

1. Set the master plane with due care so that it does not contact the drum.

2. When putting the master plane, shift the reverse guide a little in the loading direction. Care must be taken since excessive shift results in damage.

Master plane

Supply reel disk

Cassette lock release shaft

Take-up reel disk

Figure 8-5.

Note:

• Check that the reel disk is lower than part A but higher than part B. If the height is not correct, readjust the reel disk height by changing the poly-slider washer under the reel disk.

DV-NC70U/C DV-NC72U

Note:

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

Master plane

10 ± 0.2mm

Reel disk

Reel disk height adjusting jig

Mechanism chassis

Figure 8-6.

8-8 CHECKING AND ADJUSTMENT OF TAKE-

UP TORQUE IN FAST FORWARD MODE

• Remove the cassette housing control assembly.

• After short-circuiting between TP803 and TP802 provided at operation PWB, plug in the power cord.

• Setting

1. Set a torque gauge to zero on the scale. Place it on the take-up reel disk.

2. Press the FF button.

3. To calculate the remaining capacity of the play back mode, slowly rotate the supply reel disk, and then shift it into the forward mode.

Notes:

1. Hold the torque gauge by hand so that it is not moved.

2. Do not keep the reel disk in lock state. Do not allow longtime measurement.

8-9 CHECKING AND ADJUSTMENT OF TAKE-

UP TORQUE IN REWIND MODE

• Remove the cassette housing control assembly.

• After short-circuiting between TP803 and TP802 provided at operation PWB, plug in the power cord.

• Setting

1. Set a torque gauge to zero on the scale. Place it on the supply reel disk.

2. Press the rewind button.

3. To calculate the remaining capacity, slowly rotate the take-up reel disk, and then shift it into the rewind mode.

• Checking

1. Turn the torque gauge slowly (one rotation every 2 to 3 seconds) by hand in the CCW direction.

2. Make sure that the indication of torque gauge is not less than 25mN·m (255gf·cm).

Torque gauge

• Checking

1. Turn the torque gauge slowly (one rotation every 2 to 3 seconds) by hand in the CW direction.

2. Make sure that the indication of torque gauge is not less than 25mN·m (255gf·cm).

Torque gauge

25mN·m (255gf·cm) or more

Idler ass'y

The gauge is held at its maximum value. (Red mark)

Figure 8-7.

• Adjustment

1. If the FF winding-up torque is less than the specified value, clean the capstan D.D. pulley, reel belt, and limiter pulley with cleaning liquid, and check again.

2. If the torque is less than the set value, replace the reel belt.

25mN·m (255gf·cm) or more

CCW

The gauge is held at its maximum value. (Red mark)

Supply reel disk

Idler ass'y

Figure 8-8

• Adjustment

1. If the rewind winding-up torque is less than the specified value, clean the capstan D.D. pulley, reel belt, and limiter pulley with cleaning liquid, rewind again, and check the winding-up torque.

2. If the winding-up torque is still out of range, replace the drive belt.

DV-NC70U/C DV-NC72U

Notes:

1. Hold the torque gauge by hand so that it is not moved.

2. Do not keep the reel disk in lock state. Do not allow longtime measurement.

8-10 CHECKING AND ADJUSTMENT OF TAKE-

UP TORQUE IN RECORD/PLAYBACK MODE

• Remove the cassette housing control assembly.

• After short-circuiting between TP803 and TP802 provided at operation PWB, plug in the power cord.

• Turn off the power switch.

• Open the cassette torque meter lid, and fix it with tape.

• Load the cassette torque meter into the unit.

• Put the weight (500g) on the cassette torque meter.

• Turn on the power switch.

• Press the picture record button, and set EP picture record mode (x3).

Set value EP 6.9

+2.0

mN⋅m (70

–2.5

+20 –25

gf⋅cm)

8-11 CHECKING AND ADJUSTMENT OF TAKE-

UP TORQUE IN VIDEO SEARCH REWIND MODE

• Remove the cassette housing control assembly.

• After short-circuiting between TP803 and TP802 provided at operation PWB, plug in the power cord.

• Setting

Press the playback button and rewind button to set the video search rewinding mode.

• Checking

Place the torque gauge on the supply reel disk, and turn it counterclockwise very slowly (one rotation every 1 to 2 seconds) and check that the torque is within the set value

14.1 ± 3.5mN⋅m. (144 ± 35gf⋅cm)

Torque gauge

CCW

500g

Cassette torque meter

Figure 8-9.

• Checking

1. Make sure that value is within the setting 6.9 mN·m

+20

(70 gf·cm).

–25

+2.0 –2.5

2. The winding-up torque fluctuates due to variation of rotation torque of limiter pulley ass'y. Read the center value of fluctuation as setting.

3. Set the EP record mode (x3) and make sure that the winding-up torque is within setting.

• Adjustment

If the playback winding-up torque is not within the setting, replace the limiter pulley assembly.

Note:

When the torque cassette is set, put a weight (500g) to prevent rise. When the cassette torque meter is taken out. Turn off the power switch.

Supply reel disk

Figure 8-10.

Note:

Surely put the torque gauge on the reel disk to measure. If the torque gauge is raised, accurate measurement is impossible.

• Adjustment

If the rewinding playback winding-up torque is not within the setting, replace the limiter pulley assembly.

Note:

The winding-up torque fluctuates due to variation of rotation torque of supply reel disk. Read the center value of fluctuation as setting.

8-12 CHECKING THE VIDEO SEARCH REWIND

500g

Weight to prevent float (500g)

(T-120)

BACK TENSION

• Remove the cassette housing control assembly.

• After short-circuiting between TP803 and TP802 provided at main PWB, plug in the power cord.

• Checking

1. After pressing the play button, press the rewind button, and set the video search rewind mode.

2. 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 the set value 3.7 ± 1.5mN⋅m (38 ± 15gf⋅cm).

Pinch roller

Capstan shaft

DV-NC70U/C DV-NC72U

Tension gauge 900 - 1,200gf

Tension gauge adapter

Torque gauge

CCW

Take-up reel disk

Figure 8-11.

Note:

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

8-13 CHECKING THE PINCH ROLLER

PRESSURE

* Checking can be perform with or without cassette

housing control.

Figure 8-12.

8-14 CHECKING AND ADJUSTMENT OF

TENSION POLE POSITION

* Checking can be perform with or without

cassette housing control.

• Remove the cassette housing control assembly.

• After short-circuiting between TP803 and TP802 provided at main PWB, plug in the power cord.

• Setting (without cassette housing control)

1. Turn off the power switch.

2. Open the cassette tape (T-120), and fix with tape.

3. Set the cassette tape in loading state.

4. Put the weight (500g) on the cassette tape.

5. Turn on the power switch.

6. Make the adjustment with the beginning of a T-120 tape.

• Setting (with cassette housing control)

1. Insert cassette tape (T-120)

2. Make the adjustment with the beginning of a T-120 tape.

• Remove the cassette housing control assembly.

• After short-circuiting between TP803 and TP802

• Checking

Press the play button to set the playback mode.

1. Detach the pinch roller from the capstan shaft.

2. Engage the tension gauge adapter with the pinch roller

3. Gradually return the pinch roller, and measure the

4. Make sure that the measured value is within setting

provided at main PWB, plug in the power cord.

Do not separate excessively. Or the pinch lever and pinch double action lever may disengage.

shaft, and pull in the arrow direction. pulling force when the pinch roller contacts the capstan

shaft. change to 9.8 ± 2N (1.0 ± 0.2kgf).

Figure 8-13.

DV-NC70U/C DV-NC72U

• Checking

1. Set a cassette tape, push the REC button to place the unit in the SP record mode. Now check the tension pole position.

2. Visually check to see if the position of the tension pole is within the 0 mm from the left side line.

Make the adjustment with the beginning of a T-120 tape.

+0.5 –0.2

Standard A = 0 mm

+ 0.5

- 0.2

Figure 8-14.

At left side from the reference line. (A).

Tension pole adjustment driver adjusting direction

CCW

Tension pole adjustment driver

Figure 8-17.

8-15 CHECKING AND ADJUSTMENT OF

RECORD/PLAYBACK BACK TENSION

* Checking can be perform with or without

cassette housing control.

• Remove the cassette housing control assembly.

• After short-circuiting between TP803 and TP802 provided at main PWB, plug in the power cord.

Figure 8-15.

Insert the tension pole adjustment driver to main chassis hole, and rotate counterclockwise.

At right side from the reference line. (A).

• Setting (without cassette housing control)

1. Turn off the power switch.

2. Open the cassette torque meter and fix with tape.

3. Set the cassette torque meter in loading state.

4. Put the weight (500g) on the cassette torque meter.

5. Turn on the power switch.

• Setting (with cassette housing control)

1. Insert cassette torque meter.

500g

Cassette torque

Weight to prevent float (500g)

meter

Figure 8-18.

Figure 8-16.

Insert the tension pole adjustment driver to main chassis hole, and rotate clockwise.

• Checking

1. Push the REC button to place the unit in the SP record

mode.

2. At this time ascertain that the back tension is within the

setting 3.9 to 5.5mN⋅m (40 to 56gf·cm) by seeing the indication of torque cassette meter.

DV-NC70U/C DV-NC72U

• Adjustment

1. If the indication of torque cassette meter is lower than the setting, shift the tension spring engagement to the part A.

2. If the indication of torque cassette meter is higher than the setting, shift the tension spring engagement to the part B.

Tension arm

Tension spring

Figure 8-19.

8-16 CHECKING THE BRAKE TORQUE

• Checking the brake torque at the supply side

Torque gauge

• Checking the brake torque at the take-up side

Torque gauge

Take-up reel disk

CCW: 4.41 ± mN ⋅m (45 ± gf⋅cm) CW: 4.12

+2.0 –1.5 +1.5

± mN⋅m (42 ± gf⋅cm)

–1.2

CCW

+20 –15 +15 –12

Figure 8-21.

• Remove the cassette housing control assembly.

• After short-circuiting between TP803 and TP802 provided at main PWB, plug in the power cord.

CCW

CCW: 4.41 ± mN⋅m (45 ± gf⋅cm) CW: 4.12 ± mN⋅m (42 ± gf⋅cm)

+2.0 –1.5 +1.5 –1.2

Supply reel disk

+20 –15 +15 –12

Figure 8-20.

• Remove the cassette housing control assembly.

• After short-circuiting between TP803 and TP802 provided at main PWB, plug in the power cord.

• Setting

1. Set a torque gauge to zero on the scale. Place it on the supply reel disk.

2. Switch from the FF mode to the STOP mode.

3. Disconnect the power cord.

4. Please check Idler gear not contact with reel relay gear (SU side)

• Setting

1. Switch from the FF mode to the STOP mode.

2. Disconnect the power cord.

3. Set a torque gauge to zero on the scale. Place it on the take-up reel disk.

4. Please check Idler gear not contact with reel relay gear (TU side)

• Checking

1. Turn the torque gauge at a rate of about one turn/2 sec in the CCW direction/CW direction so that the reel disk and torque gauge pointer rotates at equal speed and make sure that the value is within the setting (CCW direction: 4.41 ± 1mN·m (45 ± gf·cm), CW direction:

+1.5

4.12 ± 1.mN·m (42 to gf·cm).

–1.2

+2.0 –1.5

+15 –12

+20 –15

2. Adjustment of the brake torque at the supply side and the take-up side

• Unless the supply side brake torque or take-up side brake torque is within the setting, clean the felt surface of reel disk (supply, take-up) brake lever, check again the brake torque.

• If value cannot be set within the setting yet, replace the main brake ass'y or main brake spring.

• Checking

Turn the torque gauge at a rate of about one turn/2 sec in the CW direction/CCW direction with respect to the supply reel disk so that the reel disk and torque gauge pointer rotate at equal speed, and make sure that the value is within the setting (CW direction: 4.12 ± mN·m

+15

(42 gf·cm); CCW direction: 4.41 mN·m (45 15gf·cm).

–12

+2.0 –1.5

+1.5

–1.2 +20 –15

DV-NC70U/C DV-NC72U

8-17 REPLACEMENT OF A/C (AUDIO/CONTROL)

HEAD

1. In eject position unplug the power cord.

• Removal

1. Take out FFC holder from main chassis. (Push 3 hooking point and pull-up the holder).

2. Remove the screws 123, Tilt screw.

3. Unsolder the PWB fitted to the A/C head.

Notes:

1. When replacing, never touch the head. If you touched, clean with the cleaning liquid.

2. When removing the screw 3, take care so that the spring may out.

A/C head screw

Azimuth spring

*Derection designation. (The bottom part is big.)

Azimuth adj. screw

A/C head PWB ass'y (with A/E)

Tilt screw

A/C head PWB

AC Head FFC Holder

3. Align the left end of gear of A/C head arm with the punched mark of chassis, tentatively tighten the screws 1 so as to ensure smooth motion of A/C head arm. Tightening torque must be 0.45 ± 0.05N·m (4.5 ±

0.5kgf·cm).

Height screw

Left end of A/C head arm gear Punched line mark on chassis

Figure 8-24.

Notes:

1. If the screw 1 is tighten tentatively too loose, the azimuth and height of A/C head may change when they are finally tightened. Therefore care must be taken.

2. After completion of A/C head be sure to adjust tape running. (Execute the running adjustment by the method described in 8-19.)

Height adj. screw

A/C head plate

Height Adj. spring

Figure 8-22.

• Replacement

1. Solder the removed PWB to the new head assembly.

2. Adjust the height from the A/C head arm (lower surface) to the A/C head plate to 10.8mm with slide calipers. (3 places of azimuth screw section, tilt screw section and A/ C head front section) (See the figure below.)

New A/C head ass'y

A/C head PWB

Solder

A/C head plate

*Fit the groove of FFC to the boss of the holder.

A/C head FFC

A/C FFC holder

10.8mm

Figure 8-23.

+ 64 hidden pages