Sharp DV-NC70 User manual

DV-NC70/W
DV-NC70X/RU
S92Q5DV-NC70/
SERVICE MANUAL
CONTENTS
In the interests of user-safety (Required by safety regula-
tions in some countries) the set should be restored to its
original condition and only parts identical to those specified
be used.
MODELS
DV-NC70
DV-NC70W
DV-NC70X
DV-NC70RU
VCR/DVD COMBINATION MODEL
SHARP CORPORATION
OPEN/CLOSE
EJECT/STOP
REW
REC
CH VCR/DVD
SELECTOR
TIMER
VCR DVD
PLAY STOP
AV 2 IN VIDEO L(MONO)-AUDIO -R
/
OPERATE PLAY/×2
Page
1. IMPORTANT SERVICE NOTES ........................................................................................................ 2
2. FEATURES ........................................................................................................................................ 3
3. SPECIFICATIONS ............................................................................................................................. 3
4. PART NAMES .................................................................................................................................... 5
5. MAINTENANCE CHECK ITEMS AND EXECUTION TIME ............................................................... 8
6. DISASSEMBLY METHOD ................................................................................................................. 9
7. OPERATION OF PICKUP ............................................................................................................... 13
8. ADJUSTMENT, REPLACEMENT AND ASSEMBLY OF MECHANICAL UNITS ............................ 14
9. TEST MODE .................................................................................................................................... 37
10. TROUBLESHOOTING ..................................................................................................................... 40
11. BLOCK DIAGRAMS ......................................................................................................................... 54
12. SCHEMATIC DIAGRAMS ................................................................................................................ 62
13. PRINTED WIRING BOARD ASSEMBLIES ..................................................................................... 78
14. REPLACEMENT PARTS LIST ........................................................................................................ 95
15. PACKING OF THE SET ................................................................................................................. 114
SERVICE MANUAL VCR/DVD COMBINATION MODEL MODELS DV-NC70/W/X/RU

2
DV-NC70/W
DV-NC70X/RU
1. IMPORTANT SERVICE NOTES
Note:
This unit can be used only where the power
supply is AC 110V-240V, 50/60Hz (DV-NC70/W/RU
only) and AC 240V, 50Hz (DV-NC70X only).
It cannot be used elsewhere.
CAUTION:
USE OF CONTROLS OR ADJUSTMENTS OR
PERFORMANCE OF PROCEDURES OTHER
THAN THOSE SPECIFIED HEREIN MAY RESULT
IN HAZARDOUS RADIATION EXPOSURE.
DO NOT STARE INTO THE LASER BEAM OR
VIEW WITH OPTICAL INSTRUMENT.
WARNING:
TO REDUCE THE RISK OF FIRE OR ELECTRIC
SHOCK, DO NOT EXPOSE THIS EQUIPMENT TO
RAIN OR MOISTURE.
TO REDUCE THE RISK OF FIRE OR ELECTRIC
SHOCK, AND ANNOYING INTERFERENCE, USE
THE RECOMMENDED ACCESSORIES ONLY.
Laser Diode Properties
Material: AlGaInP
Wave length: 650 nm
Emission Duration: Continuous
Laser output: Max. 0.7 mW
This Unit is classified as a CLASS 1 LASER
product.
The CLASS 1 LASER PRODUCT label is located
on the rear cover.
This product contains a low power laser device.
To ensure continued safety do not remove any
cover or attempt to gain access to the inside of
the product. Refer all servicing to qualified
personnel.
Power Cord Protection
To avoid any malfunctions of the unit, and to protect
against electric shock, fire or personal injury, please
observe the following.
Hold the plug firmly when connecting or
disconnecting the AC power cord.
Keep the AC power cord away from heating
appliances.
Never put any heavy object on the AC power cord.
Do not attempt to repair or reconstruct the AC
power cord in any way.
VARO! AVATTAESSA OLET ALTTIINA LASERSÄTEILYLLE.
ÄLÄ TUIJOTA SÄTEESEEN ÄLÄKÄ KATSO SITÄ OPTISEN LAITTEEN LÄPI.
VARNING - LASERSTRÅLNING NÄR DENNA DEL ÄR ÖPPNAD.
STIRRA EJ IN STRÅLEN OCH BETRAKTA EJ STRÅLEN GENOM OPTISKT
INSTRUMENT.
(Rear of product)
CAUTION-LASER RADIATION WHEN OPEN. DO NOT STARE INTO BEAM
OR VIEW DIRECTLY WITH OPTICAL INSTRUMENTS.
VORSICHT-LASERSTRAHLUNG, WENN GEFFNET. BLICKEN SIE NICHT IN DEN STRAHL
UND BETRACHTEN SIE DIESEN NICHT DIREKT MIT OPTISCHEN INSTRUMENTEN.
ATTENTION-RADIATION LASER EN CAS D'OUVERTURE. NE PAS FIXER LE
FAISCEAU NI REGARDER DIRECTEMENT DES INSTRUMENTS OPTIQUES.
VARNING-LASERSTRÅLNING NÄR DENNA DEL ÄR ÖPPNAD. STIRRA EJ IN
I STRÅLEN OCH BETRAKTA EJ STRÅLEN MED OPTISKA INSTRUMENT.
VARO ! AVATTAESSA OLET ALTTIINA LASERSÄTEILYLLE. ÄLÄ TUIJOTA
SÄTEESEEN ÄLÄKÄ KATSO SITÄ OPTISEN LAITTEEN LAPI.
VARNING-LASERSTRÅLNING NÄR DENNA DEL ÄR ÖPPNAD. STIRRA EJ IN I
STRÅLEN OCH BETRAKTA EJ STRÅLEN GEMON OPTISKT INSTRUMENT.
ADVARSEL-LASERSTRÅLING NÅR DEKSEL ÅPNES. STIRR IKKE INN I
STRÅLEN ELLER SE DIREKTE MED OPTISKE INSTRUMENTER.
ADVARSEL-LASERSTRÅLING VED ÅBNING. SE IKKE IND I STRÅLEN-
HELLER IKKE MED OPTISKE INSTRUMENTER.
SA005WJ
CLASS 1
LASER PRODUCT

3
DV-NC70/W
DV-NC70X/RU
2. FEATURES
ËË
ËË
ËCommon Features
•A DVD, Audio CD, Video CD player and VCR all in one.
•Simultaneous VCR recording and DVD playback.
ËË
ËË
ËVCR
•Hi-Fi Stereo Sound, NICAM/IGR System
•380-times High Speed Rewind Function (in NTSC)
•S-VHS Simple Playback
•HQ (High Quality) Circuitry
•Simple Recording Timer
•Sharp Super Picture
•G-CODE System* (DV-NC70W only)
*For Hong Kong: G-CODE is a resistered trademark of Gemstar Development Corporation. The G-CODE System is
manufactured under license from Gemstar Development Corporation.
ËË
ËË
ËDVD
•Plays DVD, Video CD and Audio CD 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
•Dolby Digital*1/DTS*2, MPEG Audio digital out capability
•High-quality digital images
•High-quality digital sound
*1Manufactured under license from Dolby Laboratories. "Dolby" 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 PAL/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 PBjack: RCA Pin-jack
Component PRjack: 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 Two rotary head helical scan system
Number of video heads 4
Video signal standard PAL/NTSC colour 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 (PAL) (SP) 23.39 mm/sec.
(LP) 11.7 mm/sec.
(EP) 7.8 mm/sec.
(NTSC) (SP) 33.35 mm/sec.
(LP) 16.67 mm/sec. (Playback only)
(EP) 11.12 mm/sec.

4
DV-NC70/W
DV-NC70X/RU
3-1. ACCESSORIES
Accessories: Remote control unit ×1, "AA" size battery (R-6, UM/SUM-3) ×2,
VIDEO/AUDIO cable ×1, RF cable (75 Ohm, 1 m [3-1/4 ft.]) ×1,
Operation Manual ×1, Guarantee Card [DV-NC70X/RU only]
Maximum recording time (PAL) (SP) 240 min. (E-240)
(LP) 480 min. (E-240)
(EP) 720 min. (E-240)
(NTSC) (SP) 160 min. (T-160)
(EP) 480 min. (T-160)
Channel coverage VHF 1A~S41, UHF E21~E69 [DV-NC70/W/RU]
VHF AU0~AU13, UHF AU28~AU69 [DV-NC70X]
Antenna input 75 ohm unbalanced
Video input Input level: 0.5 to 2.0 Vp-p (75Ω)
Video output Output level: 1.0 Vp-p (75Ω)
Audio input Input level: –8 dBs (47kΩ)
(0 dBs = 0.775 Vrms)
Audio output Output level: –8 dBs (1kΩ)
(0 dBs = 0.775 Vrms)
Hi-Fi audio Dynamic range: 90 dB
Frequency response: 20 Hz~20 kHz
Memory backup 60 minutes
DVD
DVD/VCR shared video output Output level: 1 Vp-p (75Ω)
Component colour output Y output level: 1 Vp-p (75Ω)
PBoutput level: 0.525 Vp-p (75Ω)/75% colour
PRoutput level: 0.525 Vp-p (75Ω)/75% colour
S video output Y output level: 1 Vp-p (75Ω)
C output level: 0.3 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 (JEITA)
S/N ratio CD: 96 dB, 1 kHz (JEITA)
Dynamic range DVD linear PCM: 96 dB (JEITA)
CD: 96 dB (JEITA)
Total harmonic distortion ratio CD: 0.006% (JEITA)
Pickup Wave length: 650 nm (DVD) / 780 nm (CD)
Laser output: Max. 0.7 mW
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 110~240V AC, 50/60 Hz [DV-NC70/W/RU]
240V AC, 50Hz [DV-NC70X]
Power consumption 23 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.

5
DV-NC70/W
DV-NC70X/RU
OPEN/CLOSE
EJECT/STOP
REW
REC
CH
VCR/DVD SELECTOR
TIMER
VCR DVD
PLAY STOP
AV 2 IN VIDEO L(MONO)-AUDIO-R
/
OPERATE PLAY/×2
Disc tray
OPEN/CLOSE
OPERATE
TITLE
Indicator
Operation status/Time Indicator
TRACK
Indicator
CHAPTER
Indicator
Disc operation
buttons (PLAY, STOP)
PROGRAM Indicator
REPEAT Indicator
ANGLE Indicator
VIRTUAL surround
Indicator
1
2
VCR/DVD SELECTOR
VCR DVD Indicator
DVD Main Unit (Front)
DVD Front Panel Display
You can toggle between 1and 2by
pressing the remote control unit’s
DISPLAY button.
LINE IN 2
4. PART NAMES
VCR Main Unit (Front)
OPEN/CLOSE
EJECT/STOP
REW
REC
CH
VCR/DVD SELECTOR
TIMER
VCR DVD
PLAY STOP
AV 2 IN VIDEO L(MONO)-AU DIO-R
/
SEPVP D
VCR
LR
OPERATE PLAY/×2
VCR/DVD SELECTOR
OPERATE
REC
Clock Indicator
Channel Indicator
Tape Counter Indicator
PLAY/×2
Front AUDIO/
VIDEO input
jack
Timer Recording
Indicator
Tape Speeds
Indicator
Operation status
Indicator
Cassette compartment
EJECT/STOP
CH
REW
TIMER indicator
Audio Output
Indicator
VCR Front Panel Display

6
DV-NC70/W
DV-NC70X/RU
Main Unit (Rear)
DVD OUT
LINE OUT 2
VCR
DVD/VCR
ANTENNA IN
RF OUT
LINE IN 1
AUDIO
R
L
VIDEO
AUDIO
R
L
VIDEO
LINE OUT 1
DIGITAL
AUDIO
AUDIO
R
L
S-VIDEO
Y
P
R
(C
R
)
P
B
(C
B
)
COMPONENT
DVD OUT
LINE OUT 2
VCR
DVD/VCR
ANTENNA IN
RF OUT
LINE IN 1
AUDIO
R
L
VIDEO
AUDIO
R
L
VIDEO
LINE OUT 1
DIGITAL
AUDI O
AUDI O
R
L
S-VIDEO
Y
P
R
(C
R
)
P
B
(C
B
)
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

7
DV-NC70/W
DV-NC70X/RU
Remote (VCR Operation Buttons)
•The explanations on this page use the VCR/DVD CHANGE Switch in the VCR position.
PROG
DV- NC70
DV- NC70X
DV- NC70RU
G-CODE
DV- NC70W
/
REV FWD
PLAY
STOP
OPEN/
CLOSE
VCR/DVD
SELECTOR VCR MENU
DVD SETUP
TAPE
SPEED
ON
SCREEN
TITLE
DVD MENU
DISPLAY
FUNCTION
CONTROL
PROG/
REPEAT
CLEAR
RETURN
OPERATE
TIMER
ON/OFF
EJECT
SET
ENTER
ZERO BACK
SKIP SEARCH
VCR DVDAM/PM
INPUT SELECT
PAUSE/STILL
REC
SLOW
CH
VCR DVD
SKIP
DPSS
AUDIO
OUTPUT
VCR/DVD COMBINATION
/
ANGLE
SLOW
—
/
±
, DPSS
—
/
±
AM/PM or
ON SCREEN
TIMER ON/OFF
OPERATE
DISPLAY
CLEAR
CURSOR ( / / / )
Number buttons
PLAY
REW
REC
STOP
TAPE SPEED
VCR/DVD CHANGE Switch
VCR/DVD SELECTOR
EJECT
VCR MENU
SET
ZERO BACK
SKIP SEARCH
VCR DVD
PAUSE/ STILL
INPUT SELECT
SLOW
AUDIO OUTPUT
CH /
FF
PAUSE/ STILL
REV FWD
PLAY
STOP
OPEN/
CLOSE
VCR/DVD
SELECTOR VCR MENU
DVD SETUP
TAPE
SPEED
ON
SCREEN
TITLE
DVD MENU
DISPLAY
FUNCTION
CONTROL
PROG/
REPEAT
CLEAR
RETURN
OPERATE
TIMER
ON/OFF
EJECT
SET
ENTER
ZERO BACK
SKIP SEARCH
VCR DVDAM/PM
INPUT SELECT
PAUSE/STILL
REC
SLOW
CH
VCR DVD
SKIP
DPSS
AUDIO
OUTPUT
VCR/DVD COMBINATION
/
ANGLE
ON SCREEN
OPERATE
DISPLAY
FUNCTION CONTROL
RETURN
TITLE
CURSOR ( / / / )
Number buttons
REV
STOP
VCR/DVD SELECTOR
PROG, REPEAT
ANGLE
PLAY
DVD MENU
OPEN/CLOSE
DVD SETUP
ENTER
FWD
SLOW
VCR/DVD CHANGE Switch
SKIP
•Do not subject the Remote to shock, water or excessive humidity.
•The Remote may not function if the Product 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 for an extended period of time.
Remote (DVD Operation Buttons)
•The explanations on this page use the VCR/DVD CHANGE Switch in the DVD position.

8
DV-NC70/W
DV-NC70X/RU
5. MAINTENANCE CHECK ITEMS AND EXECUTION TIME
Parts Maintained 1,000 hrs. 2,000 hrs.
Pickup
Spindle Unit
Sled Motor
Loading Motor
Belt
Note : Part Replacement
: Cleaning
(For cleaning, use a lint-free cloth danpened with pure isopropyl alcohol.)
Use the following table as a guide to maintain the mechanical parts in good operating condition.
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.
MECHANICAL PARTS REGUIRING PERIODICAL INSPECTION

9
DV-NC70/W
DV-NC70X/RU
6. DISASSEMBLY METHOD
6-1. DISASSEMBLY METHOD
1) Removing the cabinet.
(1) Remove the four screws 1and 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 5and tilt the PWB
toward you to remove it.
(2) Release the one hook 6and 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 8and two screws 9.
(3) Remove the two screws 0 to remove the Angle (DVD) .
(4) Remove the DVD Shield (lower) q.
2
1
1
4
3
5
6
4
4
4
9
10
9
10
8
7
12
11
(5) Remove the four screws wto remove the DVD Main PWB
Unit from Angle (DVD).

10
DV-NC70/W
DV-NC70X/RU
13
16
14
15
19
18
17
20
(6) Remove the two screws e to remove the Power PWB
Unit.
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 four 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.

11
DV-NC70/W
DV-NC70X/RU
Parts Code Price Code Name/Description
QCNW-A361WJZZ AN Extension cable (wire), 9pin 130mm
DVD Main CN3201–Power CN201
6-2. EXTENSION CABLE USE POINT (ONE PLACE)
Extension Cable Diagram
Power PWB
CN201
Tuner
CN3201
DVD Main PWB
DVD Mechanism
VCR Operation PWB DVD Operation PWB
VCR Mechanism
VCR Main PWB
QCNW-A361WJZZ
9 pin
MPX/SKEW PWB

12
DV-NC70/W
DV-NC70X/RU
<Replacing the Pickup and the Spindle Motor>
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.
Front Side
Sled Motor Lead Wire
Pickup FFC
Traverse Fixing Screw
Loading Motor Lead Wire
Pickup Interface PWB
Pickup FFC
Short Land
6-3. REPLACEMENT OF MAIN PARTS
<Take out disk>
1. Remove the mechanism with angle from the set. (refer to 33 on page 112. 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.
<Disassembling and assembling the mechanism chassis>
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 112).
3. Remove P , Q from the DVD Main PWB Unit 27 . (Pickup Relay FFC 58 isn't removed.) (refer to the illustration on page 112)
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.

13
DV-NC70/W
DV-NC70X/RU
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 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.
FO+
TR–
TR+
FO–
ACTUATOR
OSC V
OS
–
+
–
+
–
+
–
+
HOLOGRAM LASER UNIT
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
1
TR–
FO+
TR+
FO–
VR
PD
V
CC
GND
LD
GND
V
OS
NC
NC
V
ref (VCC/2)
VA
VD
NC
GND
VB
VC
(NC)
Power adjust
HIGH-FREQUENCY CONVOLUTION
LD
PD
VA
VB
VC
VD
V
ref
V cc
GND
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.
2-focus objective lens
Actuator assembly
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 3 of IC3301 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).
7-4-4. Laser diode drive current control (LD)
Power supply to drive the laser diode
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.
LD PD
7-4-6. HF Signal (VA, VB, VC, VD)
Signals recorded in the disk
When the quantity of laser light increases, the
current shown in figure increases and the PD
terminal voltage rises.
IC3301 is used to control. The LD terminal voltage
lowers, and the quantity of light reduces. (IC3301
is actuated by voltage input.)

14
DV-NC70/W
DV-NC70X/RU
VROCPSV CK
11. JiGHMEC-M005 CK
10. JiGDRiVER-6 BM
9. JiGDRiVERH-4 AP
4. Torque Driver JiGTD1200 CB
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.
JiGTG1200 CN
JiGMP0001 BY
1. Torque Cassette Meter JiGVHT-063 CZ
No. Jig ltem Part No. Code Configuration Remarks
JiGTG0090 CM
3. Torque Gauge Head JiGTH0006 AW
JiGRH0002 BR
JiGSG2000 BS
JiGSG0300 BF
7. JiGADP003 BK
Tension Gauge
These Jigs are used for checking
and adjusting the reel disk height.
When fixing any part to the threaded
hole using resin with screw, use the
jig. (Specified torque 5 kg)
This cassette torque meter is used for check-
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.
Master Plane Jig and
Reel Disk Height
Adjusting Jig
Pinch pressing force
measuring jig
This Jig is used with the tension
gauge. Rotary transformer clearance
adjusting jig.
There are two gauges used for the
tension measurements, 300 g and
2.0 kg.
These tapes are especially used for
electrical fine adjustment.
Video Audio HiFi Audio Track
625 Monoscope 7k — 49µm
PAL Colour Bar 1k — 49µm
This screwdriver is used for adjusting the
guide roller height.
For X value adjustment
This Jig is used for adjustment
of tension pole.
X value adjustment
gear driver
Tension Pole
Adjustment Driver
2. Torque Gauge
6.
5.
8. Alignment Tape
Guide roller height
adjustment driver

15
DV-NC70/W
DV-NC70X/RU
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.
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.
Maintained
Parts Remarks
500
hrs.
1000
hrs.
1500
hrs.
2000
hrs.
Possible symptom
encountered
Guide roller ass’y
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
Supply/take-up main brake levers
AHC (Automatic head cleaner)
Colour and beating
Small sound or sound
distortion
Poor S/N ratio, no colour
Poor flatness of the
envelope with alignment
tape
No tape running,
uneven colour
No tape running, tape
slack
No tape running, tape
slack, no fast forward/
rewind motion
Lateral noises Head
occasionally blocked
Abnormal rotation or significant
vibration requires replacement.
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.
Replace the roller of the cleaner
when it wears down.
Just change the AHC roller
assembly for new one.
Screen swaying
Cassette not loaded or
unloaded
No tape running, tape
slack
Tape slack
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.
•Whenever the video head is cleaned, replace the clean-
ing 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
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.

16
DV-NC70/W
DV-NC70X/RU
8-3. FUNCTION OF MAJOR MECHANICAL PARTS (TOP VIEW)
No. Function 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
8 Take-up main brake
9 Pinch drive cam
10 A/C head ass’y
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
18 Take-up pole base ass'y
26 Auto head cleaner ass'y
17 15 26
11
5
9
14
12
8
16
13
4
6
2
7
3
1
18 10





17
DV-NC70/W
DV-NC70X/RU
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 Sifter
25
24
21
22
19
20
23





18
DV-NC70/W
DV-NC70X/RU
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 Main PWB
have been installed)
8-4-1. DISASSEMBLING THE MECHANISM
1. When removing the mechanism from the set.
Remove the two screws 1which 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 2fixing the cassette housing
to the mechanism, and remove the cassette housing.
PinchDrive Cam
Synchro Gear
Master cam
Main Chassis Drive Lever
8-4. DISASSEMBLY AND REASSEMBLY
Cassette Control
Housing
Mechanism
Chassis
Main PWB
21

19
DV-NC70/W
DV-NC70X/RU
INSTALLING THE MECHANISM ON MAIN 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.
PARTS WHICH NEED PARTICULAR CARE
When installing the mechanism chassis on the Main PWB
unit, take care so as to prevent deformation due to contact
of mechanism chassis with REC Tip SW.
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.
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.
•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.)
90°
180°
270°
0°
Connectorfor
CapstanMotor
Connectorfo
r
ACHead
ConnectorforR/T
AEConnector
EndSensor
RECTipSW
This positioning hole
should be at frontside.
Master Cam Position MODE SW Position
MODE SW
Start Sensor
This pin should be
at frontside.

20
DV-NC70/W
DV-NC70X/RU
• Reassembly
1. Before installing the cassette housing control, short-
circuit between TP803 and TP802 provided at VCR
Operation 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 paral-
lel 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.
Figure 8-2.
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 per-
form 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 on VCR
Operation PWB.
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 8-3.
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.
500g
Weight to prevent
float (500g)
Mechanism chassis
From Bottom View
Pinch Drive
Cam
Synchro
Gear
Master
cam
From top view
Main chassis
Drive
Lever
Phase
matching
Master cam
Line of
synchro
gear.
Hole of Pinch
drive cam.
Figure 8-1.
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.
1
Main shaft
Cassette
housing