JVC GRAX970U - Service Manual Immediate Download

SERVICE MANUAL

No. 86663

January 2002

SPECIFICATIONS (The specifications shown pertain specifically to the model GR-AX770)

COMPACT VHS CAMCORDER

Printed in Japan

This service manual is printed on 100% recycled paper.

GR-AX770U/AX970U

No.

86663

GR-AX770U/AX970U

JVC SERVICE & ENGINEERING COMPANY OF AMERICA

DIVISION OF JVC AMERICAS CORP.

Head office

East Coast

Midwest

West Coast

Atlanta

Hawaii

1700 Valley Road Wayne, New Jersey 07470-9976

10 New Maple Avenue Pine Brook, New Jersey 07058-9641

705 Enterprise Street Aurora, Illinois 60504-8149

5665 Corporate Avenue Cypress, California 90630-0024

1500 Lakes Parkway Lawrenceville, Georgia 30043-5857

2969 Mapunapuna Place Honolulu, Hawaii 96819-2040

(973)317-5000

(973)396-1000

(630)851-7855

(714)229-8011

(770)339-2582

(808)833-5828

JVC CANADA INC.

Head office

Montreal

Vancouver

21 Finchdene Square Scarborough, Ontario M1X 1A7

16800 Rte Trans-Canadienne, Kirkland, Quebec H9H 5G7

13040 Worster Court Richmond, B.C. V6V 2B3

(416)293-1311

(514)871-1311

(604)270-1311

S40895-04

Camcorder

General

Format

: VHS NTSC standard

Power source

: DC 11 V

(Using AC Adapter)

DC 6 V

(Using battery pack)

Power consumption

Viewfinder on

: 3.7 W

Signal system

: NTSC-type

Video recording system

Luminance

: FM recording

Color

: Converted sub-carrier direct recording

Conforms to VHS standard

Cassette

cassette

Tape speed

: 33.35 mm/sec. (1-5/16 ips)

: 11.12 mm/sec. (7/16 ips)

Recording time (max.)

: 40 minutes

: 120 minutes

(with TC-40 cassette)

Operating

temperature

: 0°C to 40°C (32°F to 104°F)

Operating humidity : 35% to 80%

Storage temperature : 20°C to 50°C (4°F to 122°F)

Weight

: Approx. 850 g (1.9 lbs)

Dimensions

: 200 mm x 112 mm x 115 mm

(W x H x D)

(7-7/8" x 4-7/16" x 4-9/16")

Pickup

: 1/4" format CCD

Lens

: F1.6, f = 3.9 mm to 62.4 mm,

16:1 power zoom lens with auto iris and macro control,

filter diameter 40.5 mm

Viewfinder

: Electronic viewfinder with 0.5" black/white CRT

White balance

adjustment

: Auto/Manual adjustment

Some accessories are not available in some areas. Please consult

your nearest JVC dealer for details on accessories and their

availability.

Specifications shown are for SP mode unless otherwise indicated.

E & O.E. Design and specifications subject to change without notice.

Connectors

Video

: 1 V (p-p), 75 Ø unbalanced, analog output (via

Video output connector)

Audio

: 300 mV (rms), 1 kØ analog output

(via Audio output connector)

AC Adapter

Power requirement

U.S.A. and Canada : AC 120 V`, 60 Hz

Other countries

: AC 110 V to 240 V`, 50 Hz/60 Hz

Output

: DC 11 V

, 1 A

Optional Accessories

· Battery Packs BN-V12U, BN-V20U, BN-V400U

· A/V (Audio/Video) Cable

· Compact VHS (

) Cassettes TC-40/30/20

· Active Carrying Bag CB-V7U

4. CHARTS AND DIAGRAMS

NOTES OF SCHEMATIC DIAGRAM .......................................... 4-1

CIRCUIT BOARD NOTES ........................................................... 4-2

4.1 BOARD INTERCONNECTIONS .......................................... 4-3

4.2 CPU SCHEMATIC DIAGRAM .............................................. 4-5

4.3 M. MDA SCHEMATIC DIAGRAM ......................................... 4-7

4.4 VTR ASP SCHEMATIC DIAGRAM ....................................... 4-9

4.5 DSP SCHEMATIC DIAGRAM ............................................. 4-11

4.6 F/Z/I/MDA SCHEMATIC DIAGRAM .................................... 4-13

4.7 V OUT SCHEMATIC DIAGRAM ......................................... 4-15

4.8 TG/CDS SCHEMATIC DIAGRAM ...................................... 4-17

4.9 REG SCHEMATIC DIAGRAM ............................................ 4-19

4.10 LCD/CVF SCHEMATIC DIAGRAM [GR-AX970U] ........... 4-21

4.11 BW/CVF SCHEMATIC DIAGRAM [GR-AX770UC] .......... 4-23

4.12 BW/CVF SCHEMATIC DIAGRAM [GR-AX970U] ............ 4-25

4.13 JACK SCHEMATIC DIAGRAM ........................................ 4-27

4.14 CCD SCHEMATIC DIAGRAM .......................................... 4-29

4.15 C-VF BL SCHEMATIC DIAGRAM [GR-AX970U] ............. 4-30

4.16 C-VF SHEMATIC DIAGRAM [GR-AX970U] ..................... 4-31

4.17 E.VF SCHEMATIC DIAGRAM [GR-AX770UC] ................ 4-33

4.18 TOP OPE UNIT, ZOOM UNIT, REAR UNIT AND SENSOR

SCHEMATIC DIAGRAMS ................................................ 4-35

4.19 MAIN CIRCUIT BOARD ................................................... 4-37

4.20 CCD CIRCUIT BOARD .................................................... 4-43

4.21 E. VF CIRCUIT BOARD [GR-AX770UC] ......................... 4-44

4.22 C-VF CIRCUIT BOARD [GR-AX970U] ............................ 4-45

4.23 WAVEFORMS .................................................................. 4-46

4.24 VOLTAGE CHARTS ......................................................... 4-47

4.25 POWER SYSTEM BLOCK DIAGRAM ............................. 4-51

4.26 CAMERA AND Y/C SYSTEM BLOCK DIAGRAM ........... 4-53

4.27 CPU/MDA SYSTEM BLOCK DIAGRAM .......................... 4-57

5. PARTS LIST

5.1 PACKING AND ACCESSORY ASSEMBLY <M1> ................ 5-1

5.2 FINAL ASSEMBLY <M2> .................................................... 5-3

5.3 MECHANISM ASSEMBLY <M3> ....................................... 5-6

5.4 ELECTRONIC VIEWFINDER ASSEMBLY <M4> [GR-AX770UC] ... 5-8

5.4 ELECTRONIC VIEWFINDER ASSEMBLY <M4> [GR-AX970U] ..... 5-9

5.5 ELECTRICAL PARTS LIST .................................................. 5-10

MAIN BOARD ASSEMBLY <01> .................................................. 5-10

CCD BOARD ASSEMBLY <02> ......................................... 5-16

C-VF BL BOARD ASSEMBLY <06>[AX970U] .................... 5-16

E.VF BOARD ASSEMBLY <60>[AX770UC] ....................... 5-16

Important Safety Precautions

INSTRUCTIONS

1. DISASSEMBLY

1.1 SERVICE CAUTIONS ............................................................ 1-1

1.1.1 Precautions ...................................................................... 1-1

1.1.2 How to read the disassembly and assembly ................... 1-1

1.1.3 Connection of the wires .................................................. 1-1

1.2 TOOLS REQUIRED FOR ADJUSTMENTS ........................... 1-2

1.3 DISASSEMBLY/ASSEMBLY OF CABINET PARTS ................ 1-3

1.3.1 Disassembly flow chart ................................................... 1-3

1.3.2 Disassembly method ....................................................... 1-4

1.4 DISASSEMBLY/ASSEMBLY OF CAMERA SECTION AND

DECK SECTION .................................................................... 1-8

1.4.1 Flowchart of disassembly ................................................ 1-8

1.4.2 Disassembly method ....................................................... 1-8

1.5 REPLACEMENT OF 3 CCD IMAGE SENSOR ................... 1-10

1.5.1 Removal of CCD image sensor ..................................... 1-10

1.5.2 Installation of new CCD image sensor .......................... 1-10

1.5.3 Replacement of CCD board assembly .......................... 1-10

1.6 TAKE OUT CASSETTE TAPE .............................................. 1-11

1.7 EMERGENCY DISPLAY ...................................................... 1-12

1.8 DEMONSTRATION MODE ................................................. 1-12

1.9 SERVICE NOTE .................................................................. 1-14

2. MECHANISM ADJUSTMENT

2.1 SERVICE CAUTIONS ............................................................ 2-1

2.1.1 Precautions ...................................................................... 2-1

2.1.2 How to read the disassembly and assembly

(For Mechanism Parts) .................................................... 2-1

2.1.3 Required adjustment tools .............................................. 2-1

2.2 DISASSEMBLY/ASSEMBLY OF MECHANISM PARTS ........ 2-2

2.3 CHECKUP AND ADJUSTMENT OF MECHANISM PHASE .. 2-6

2.4 TAPE TRANSPORT ADJUSTMENT ...................................... 2-7

2.4.1 Back tension .................................................................... 2-7

2.4.2 Tape pattern ..................................................................... 2-7

2.4.3 A/C head height & azimuth .............................................. 2-8

2.4.4 Phase of control head (X value) ....................................... 2-9

2.5 REMARKS ............................................................................ 2-9

2.5.1 Cleaning ........................................................................... 2-9

2.5.2 Applying oil and grease ................................................... 2-9

2.5.3 Checkup .......................................................................... 2-9

2.6 JIG CONNECTOR CABLE CONNECTION .......................... 2-10

3. ELECTRICAL ADJUSTMENT

3.1 ELECTRICAL ADJUSTMENT ................................................ 3-1

3.1.1 Preparation ...................................................................... 3-1

3.2 ELECTRONIC VIEWFINDER (E. VF) ADJUSTMENT

[B/W VF model only] ............................................................... 3-2

3.2.1 Tilt .................................................................................... 3-2

3.2.2 Centering ......................................................................... 3-2

3.2.3 Vertical scanning .............................................................. 3-2

3.2.4 Brightness ....................................................................... 3-2

3.2.5 Focus ............................................................................... 3-2

TABLE OF CONTENTS

Section

Title

Page

Section

Title

Page

GR-AX770U

GR-AX970U

E.VF

B/W

COLOR

DC LIGHT

NOT USED

USED

The following table lists the differing points between Models GR-AX770U and GR-AX970U in this serise.

Important Safety Precautions

Prior to shipment from the factory, JVC products are strictly inspected to conform with the recognized product safety and electrical codes of the

countries in which they are to be sold. However, in order to maintain such compliance, it is equally important to implement the following precautions

when a set is being serviced.

Fig.1

1. Locations requiring special caution are denoted by labels and in-

scriptions on the cabinet, chassis and certain parts of the product.

When performing service, be sure to read and comply with these

and other cautionary notices appearing in the operation and serv-

ice manuals.

2. Parts identified by the

! symbol and shaded (

) parts are

critical for safety.

Replace only with specified part numbers.

Note: Parts in this category also include those specified to com-

ply with X-ray emission standards for products using

cathode ray tubes and those specified for compliance

with various regulations regarding spurious radiation

emission.

3. Fuse replacement caution notice.

Caution for continued protection against fire hazard.

Replace only with same type and rated fuse(s) as specified.

4. Use specified internal wiring. Note especially:

1) Wires covered with PVC tubing

2) Double insulated wires

3) High voltage leads

5. Use specified insulating materials for hazardous live parts. Note

especially:

1) Insulation Tape

3) Spacers

5) Barrier

2) PVC tubing

4) Insulation sheets for transistors

6. When replacing AC primary side components (transformers, power

cords, noise blocking capacitors, etc.) wrap ends of wires securely

about the terminals before soldering.

Power cord

Fig.2

10. Also check areas surrounding repaired locations.

11. Products using cathode ray tubes (CRTs)

In regard to such products, the cathode ray tubes themselves, the

high voltage circuits, and related circuits are specified for compli-

ance with recognized codes pertaining to X-ray emission.

Consequently, when servicing these products, replace the cath-

ode ray tubes and other parts with only the specified parts. Under

no circumstances attempt to modify these circuits.

Unauthorized modification can increase the high voltage value and

cause X-ray emission from the cathode ray tube.

12. Crimp type wire connector

In such cases as when replacing the power transformer in sets

where the connections between the power cord and power trans-

former primary lead wires are performed using crimp type connec-

tors, if replacing the connectors is unavoidable, in order to prevent

safety hazards, perform carefully and precisely according to the

following steps.

1) Connector part number : E03830-001

2) Required tool : Connector crimping tool of the proper type which

will not damage insulated parts.

3) Replacement procedure

(1) Remove the old connector by cutting the wires at a point

close to the connector.

Important : Do not reuse a connector (discard it).

Fig.7

cut close to connector

Fig.3

(2) Strip about 15 mm of the insulation from the ends of the

wires. If the wires are stranded, twist the strands to avoid

frayed conductors.

15 mm

Fig.4

(3) Align the lengths of the wires to be connected. Insert the

wires fully into the connector.

Connector

Metal sleeve

Fig.5

(4) As shown in Fig.6, use the crimping tool to crimp the metal

sleeve at the center position. Be sure to crimp fully to the

complete closure of the tool.

·Precautions during Servicing

7. Observe that wires do not contact heat producing parts (heatsinks,

oxide metal film resistors, fusible resistors, etc.)

8. Check that replaced wires do not contact sharp edged or pointed

parts.

9. When a power cord has been replaced, check that 10-15 kg of

force in any direction will not loosen it.

1.2

2.0

5.5

Crimping tool

Fig.6

(5) Check the four points noted in Fig.7.

Not easily pulled free

Crimped at approx. center

of metal sleeve

Conductors extended

Wire insulation recessed

more than 4 mm

S40888-01

·Safety Check after Servicing

Examine the area surrounding the repaired location for damage or deterioration. Observe that screws, parts and wires have been returned

to original positions, Afterwards, perform the following tests and confirm the specified values in order to verify compliance with safety

standards.

1. Insulation resistance test

Confirm the specified insulation resistance or greater between power cord plug prongs and exter-

nally exposed parts of the set (RF terminals, antenna terminals, video and audio input and output

terminals, microphone jacks, earphone jacks, etc.). See table 1 below.

2. Dielectric strength test

Confirm specified dielectric strength or greater between power cord plug prongs and exposed acces-

sible parts of the set (RF terminals, antenna terminals, video and audio input and output terminals,

microphone jacks, earphone jacks, etc.). See table 1 below.

3. Clearance distance

When replacing primary circuit components, confirm specified clearance distance (d), (d') be-

tween soldered terminals, and between terminals and surrounding metallic parts. See table 1

below.

4. Leakage current test

Confirm specified or lower leakage current between earth ground/power cord plug prongs and

externally exposed accessible parts (RF terminals, antenna terminals, video and audio input and

output terminals, microphone jacks, earphone jacks, etc.).

Measuring Method : (Power ON)

Insert load Z between earth ground/power cord plug prongs and externally exposed accessible

parts. Use an AC voltmeter to measure across both terminals of load Z. See figure 9 and following

table 2.

5. Grounding (Class 1 model only)

Confirm specified or lower grounding impedance between earth pin in AC inlet and externally exposed accessible parts (Video in, Video out,

Audio in, Audio out or Fixing screw etc.).

Measuring Method:

Connect milli ohm meter between earth pin in AC inlet and exposed accessible parts. See figure 10 and grounding specifications.

Fig. 10

Fig. 9

Fig. 8

Table 1 Specifications for each region

Table 2 Leakage current specifications for each region

Note: These tables are unofficial and for reference only. Be sure to confirm the precise values for your particular country and locality.

S40888-01

Externally

exposed

accessible part

1-1

(1)

(2)

(3)

(4)

SECTION 1

DISASSEMBLY

1.1.3 Connection of the wires

Pull both ends of the connector in the arrow direction, re-

move the lock and disconnect the flat wire.

1.1 SERVICE CAUTIONS

1.1.1

Precautions

1. Before disassembling/re-assembling the set as well as

soldering parts, make sure to disconnect the power ca-

ble.

2. When disconnecting/connecting connectors, pay enough

attention to wiring not to damage it.

3. In general, chip parts such as resistor, shorting jumpers

(0-ohm resistor), ceramic capacitors, diodes, etc. can not

be reused after they were once removed.

4. When installing parts, be careful not to do with other parts

as well as not to damage others.

5. When removing ICs, be careful not to damage circuit pat-

terns.

6. Tighten screws properly during the procedures. Un-

less specified otherwise, tighten screws at torque of

0.196 N·m (2.0 kgf·cm).

1.1.2 How to read the disassembly and assembly

(For Cabinet Parts)

(1) Order of steps in Procedure

When reassembling, preform the step(s) in the reverse

order. These numbers are also used as the identifica-

tion (location) No. of parts Figures.

(2) Part to be removed or installed.

(3) Fig. No. showing Procedure or Part Location.

C = Cabinet

CA = Camera

D = Deck

(4) Identification of part to be removed, unhooked, un-

locked, released, unplugged, unclamped or unsoldered.

P = Spring

W = Washer

S = Screw

* = Unhook, unlock, release, unplug or unsolder.

2(S3) = 2 Screws (S3)

CN = Connector

Fig. 1-1-1

Fig. 1-1-2

CASETTE COVER

(S1), 3(L1a), (L1b), (L1c),

ASSEMBLY

Push button, Spring

UPPER CASE

2(S2), 2(L2)

LOWER CASE

9(S3), (L3a), (L3b), CN3a,

ASSEMBLY

COVER(JACK)

(Incl. E.VF ASSEMBLY)

STEP

No.

PART

Fig.

No.

REMOVAL

*UNLOCK/RELEASE/

UNPLUG/UNCLAMP/

UNSOLDER

Connector

Wire

Connector

Wire

NOTE:

After removing the wire, return the stopper to

its original position, because it is apt to come

off if it is left open.

Extend the locks in the direction of the arrow for unlocking

and then pull out the wire.