JVC HRJ677MS - Service Manual Immediate Download

SERVICE MANUAL

No. 82811

July 2000

HR-J271MS/J471MS/J677MS/J777MS

SPECIFICATIONS (The specifications shown pertain specifically to the model HR-J777MS/J677MS)

VIDEO CASSETTE RECORDER

Printed in Japan

VICTOR COMPANY OF JAPAN, LIMITED

VIDEO DIVISION

S40894

This service manual is printed on 100% recycled paper.

HR-J271MS/J471MS/J677MS/J777MS

No.

82811

PAL NTSC

SP/LP/EP

DISLAY

COLOUR SYSTEM

REC LINK

VIDEO (MONO)LAUDIOR

STANDBY/ON

REVIEW

15dB

NORM

MEN

123

VCR

CABLE/

DVD/SAT

EXPRESS

PROG

30 SEC

TV PR

TV PR +

ENTER/EN

TREE

DATE

STOP

FIN

START

DEBUT

0000

AUX

DAILY/QTDN.

VPS/PDC

WEEKLY/HEBDO

AUDIO

TV/VCR

GENERAL

Power requirement

Rating

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

Operating

: AC 90 V 260 V`, 50/60 Hz

Power consumption

: 19 W

Temperature

Operating

: 5°C to 40°C

Storage

: 20°C to 60°C

Operating position

: Horizontal only

Dimensions (WxHxD)

: 400 mm x 94 mm x 278 mm

Weight

: 3.3 kg

Format

: VHS standard

Maximum recording time

(SP)

: 240 min. with E-240 video cassette

(PAL/MESECAM)

: 160 min. with T-160 video cassette

(NTSC)

(LP)

: 480 min. with E-240 video cassette

(PAL/MESECAM)

(EP)

: 480 min. with T-160 video cassette

(NTSC)

VIDEO/AUDIO

Signal system

: PAL-type colour signal and

CCIR monochrome signal,

625 lines 50 fields

: NTSC colour and EIA

monochrome signals,

525 lines/60 fields

Recording system

: DA-4 (Double Azimuth)

head helical scan system

Signal-to-noise ratio

: 45 dB

Horizontal resolution

: 250 lines (PAL/MESECAM)

: 220 lines (NTSC)

Frequency range

: 70 Hz to 10,000 Hz (Normal audio)

20 Hz to 20,000 Hz (Hi-Fi audio)

Input/Output

: RCA connectors (IN x 2, OUT x 1)

TUNER/TIMER

TV channel storage

capacity

: 99 positions (+AUX position)

Tuning system

: Frequency synthesized tuner

Channel coverage

: VHF

(Low) 42 MHz 175 MHz

(High)175 MHz 470 MHz

UHF

470 MHz 870 MHz

Aerial output

: UHF channels (Adjustable

E28 E60)

Memory backup time

: Approx. 6 months

Estimated figure based on

supplied fresh battery; actual

performance may differ.

ACCESSORIES

Provided accessories

: RF cable,

Infrared remote control unit,

"R6/UM-3" battery x 2,

Lithium battery CR2025,

Conversion plug*

*Not provided in certain areas.

Important Safety Precautions

INSTRUCTIONS

1. DISASSEMBLY

1.1 DISASSEMBLY FLOW CHART ............................................................ 1-1

1.2 HOW TO READ THE DISASSEMBLY AND ASSEMBLY ...................... 1-1

1.3 DISASSEMBLY/ASSEMBLY METHOD ................................................ 1-1

1.4 SERVICE POSITION ............................................................................ 1-4

1.4.1 How to take out the Mechanism and Main board assemblies ......... 1-4

1.5 MECHANISM SERVICE MODE ........................................................... 1-5

1.5.1 How to set the "MECHANISM SERVICE MODE" ............................ 1-5

1.6 EMERGENCY DISPLAY FUNCTION ................................................... 1-6

1.6.1 Displaying the emergency information ............................................ 1-6

1.6.2 Clearing the emergency history ....................................................... 1-6

1.6.3 Emergency content description ....................................................... 1-7

1.6.4 Emergency detail information 1 ...................................................... 1-8

1.6.5 Emergency detail information 2 ...................................................... 1-9

1.7 SYSCON CIRCUIT ............................................................................. 1-10

1.7.1 Syscon CPU pin function (IC3001) [HR-J677MS, HR-J777MS] .... 1-10

2. MECHANISM ADJUSTMENT

2.1 BEFORE STARTING REPAIR AND ADJUSTMENT ............................. 2-1

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

2.1.2 Checking for Proper Mechanical Operations ................................... 2-1

2.1.3 Manually Removing the Cassette Tape ........................................... 2-1

2.1.4 Jigs and Tools Required for Adjustment .......................................... 2-2

2.1.5 Maintenance and Inspection ............................................................ 2-3

2.2 REPLACEMENT OF MAJOR PARTS .................................................. 2-6

2.2.1 Before Starting Disassembling (Phase matching between mechanical parts) 2-6

2.2.2 How to Set the Mechanism Assembling Mode ................................ 2-6

2.2.3 Cassette Holder Assembly .............................................................. 2-6

2.2.4 Pinch Roller Arm Assembly ............................................................. 2-8

2.2.5 Guide Arm Assembly and Press Lever Assembly ............................ 2-8

2.2.6 Audio Control Head ......................................................................... 2-8

2.2.7 Loading Motor .................................................................................. 2-8

2.2.8 Capstan Motor ................................................................................. 2-9

2.2.9 Pole Base Assembly (supply or take-up side) ................................. 2-9

2.2.10 Rotary Encoder ........................................................................... 2-10

2.2.11 Clutch Unit .................................................................................. 2-10

2.2.12 Change Lever Assembly, Direct Gear, Clutch Gear and Coupling Gear 2-10

2.2.13 Link Lever ................................................................................... 2-11

2.2.14 Cassette Gear, Control Cam and Worm Gear ............................ 2-11

2.2.15 Control Plate ............................................................................... 2-11

2.2.16 Loading Arm Gear (supply or take-up side) and Loading Arm Gear Shaft 2-12

2.2.17 Take-up Lever, Take-up Head and Control Plate Guide ............. 2-13

2.2.18 Capstan Brake Assembly ........................................................... 2-13

2.2.19 Sub Brake Assembly (take-up side) ........................................... 2-13

2.2.20 Main Brake Assembly (take-up side), Reel Disk (take-up side) and

Main Brake Assembly (supply side) .................................................. 2-13

2.2.21 Tension Brake Assembly, Reel Disk (supply side) and

Tension Arm Assembly ............................................................... 2-14

2.2.22 Idler Lever, Idler Arm Assembly .................................................. 2-14

2.2.23 Stator Assembly .......................................................................... 2-14

2.2.24 Rotor Assembly .......................................................................... 2-14

2.2.25 Upper Drum Assembly ................................................................ 2-15

2.3 COMPATIBILITY ADJUSTMENT ........................................................ 2-16

2.3.1 Checking/Adjustment of FM Waveform Linearity ........................... 2-16

2.3.2 Checking/Adjustment of the Height and Tilt of the Audio Control Head 2-17

2.3.3 Checking/Adjustment of the Audio Control Head Phase (X-Value) 2-17

2.3.4 Checking/Adjustment of the Standard Tracking Preset ................. 2-18

2.3.5 Checking/Adjustment of the Tension Pole Position ....................... 2-18

3. ELECTRICAL ADJUSTMENT

3.1 PRECAUTION ...................................................................................... 3-1

3.1.1 Required test equipments ................................................................ 3-1

3.1.2 Required adjustment tools ............................................................... 3-1

3.1.3 Color (colour) bar signal,Color (colour) bar pattern ......................... 3-1

3.1.4 Switch settings and standard precautions ....................................... 3-1

TABLE OF CONTENTS

Section

Title

Page

Section

Title

Page

HR-J271MS

HR-J471MS

HR-J677MS

HR-J777MS

VIDEO HEAD

2 HEAD

4 HEAD (DA4)

HiFi AUDIO

NOT USED

USED

HiFi LEVEL METER

NOT USED

USED

FRONT VIDEO/AUDIO INPUT(RCA)

NOT USED

USED

VCR PLUS+

NOT USED

SHOW VIEW

REMOTE PAUSE

NOT USED

USED

STILL/PAUSE/FRAME ADVANCE

REDUCED NOISE

NOISELESS

The following table lists the differing points between Models (HR-J271MS, HR-J471MS, HR-J677MS, HR-J777MS) in this series.

3.2 SERVO CIRCUIT .................................................................................. 3-2

3.2.1 Switching point ................................................................................ 3-2

3.2.2 Slow tracking preset ........................................................................ 3-2

3.3 VIDEO CIRCUIT ................................................................................... 3-2

3.3.1 AUTO PICTURE initial setting ......................................................... 3-2

3.4 SYSCON CIRCUIT ............................................................................... 3-3

3.4.1 Timer clock ...................................................................................... 3-3

4. CHARTS AND DIAGRAMS

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

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

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

4.2 VIDEO/N.AUDIO SCHEMATIC DIAGRAM [HR-J271MS, HR-J471MS] . 4-5

4.3 SYSTEM CONTROL SCHEMATIC DIAGRAM [HR-J271MS, HR-J471MS] 4-7

4.4 SWITCHING REGULATOR SCHEMATIC DIAGRAM

[HR-J271MS, HR-J471MS] .................................................................. 4-9

4.5 TUNER SCHEMATIC DIAGRAM [HR-J271MS, HR-J471MS] ........... 4-11

4.6 DISPLAY AND MINI FRONT SCHEMATIC DIAGRAMS

[HR-J271MS, HR-J471MS] ................................................................ 4-13

4.7 BS CONNECTION AND LITHIUM BATTERY SCHEMATIC

DIAGRAMS [HR-J271MS, HR-J471MS] ............................................ 4-15

4.8 TERMINAL SCHEMATIC DIAGRAM [HR-J271MS, HR-J471MS] ..... 4-16

4.9 BOARD INTERCONNECTIONS [HR-J677MS, HR-J777MS] ............ 4-17

4.10 VIDEO/AUDIO SCHEMATIC DIAGRAM [HR-J677MS, HR-J777MS] .. 4-19

4.11 ON SCREEN SCHEMATIC DIAGRAM [HR-J677MS, HR-J777MS] 4-21

4.12 SYSTEM CONTROL AND LITHIUM BATTERY SCHEMATIC

DIAGRAMS [HR-J677MS, HR-J777MS] .......................................... 4-23

4.13 SWITCHING REGULATOR SCHEMATIC DIAGRAM

[HR-J677MS, HR-J777MS] .............................................................. 4-25

4.14 TUNER SCHEMATIC DIAGRAM [HR-J677MS, HR-J777MS] ......... 4-27

4.15 DISPLAY AND MINI OPE SCHEMATIC DIAGRAMS

[HR-J677MS, HR-J777MS] .............................................................. 4-29

4.16 TERMINAL AND R.PAUSE SCHEMATIC DIAGRAMS

[HR-J677MS, HR-J777MS] .............................................................. 4-31

4.17 DEMODULATOR SCHEMATIC DIAGRAM [HR-J777MS] ............... 4-33

4.18 MAIN, A/C HEAD, MINI FRONT, LITHIUM BATTERY AND

LOADING MOTOR CIRCUIT BOARDS [HR-J271MS, HR-J471MS] ........ 4-37

4.19 MAIN, A/C HEAD, MINI OPE, R.PAUSE, LITHIUM BATTERY AND

LOADING MOTOR CIRCUIT BOARDS [HR-J677MS, HR-J777MS] ... 4-41

4.20 DEMODULATOR CIRCUIT BOARD [HR-J777MS] ......................... 4-43

4.21 FDP GRID ASSIGNMENT AND ANODE CONNECTION ............... 4-44

4.22 REMOTE CONTROL SCHEMATIC DIAGRAM ............................... 4-45

4.23 VOLTAGE CHARTS [HR-J271MS, HR-J471MS] ............................ 4-46

4.24 VOLTAGE CHARTS [HR-J677MS, HR-J777MS] ............................ 4-47

4.25 SYSTEM CONTROL BLOCK DIAGRAM ......................................... 4-49

4.26 VIDEO BLOCK DIAGRAM ............................................................... 4-51

4.27 AUDIO BLOCK DIAGRAM [HR-J271MS, HR-J471MS] ................... 4-53

4.28 AUDIO BLOCK DIAGRAM [HR-J677MS, HR-J777MS] ................... 4-55

5. PARTS LIST

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

5.2 CABINET AND CHASSIS ASSEMBLY <M2> ...................................... 5-2

5.3 MECHANISM ASSEMBLY <M4> ......................................................... 5-4

5.4 ELECTRICAL PARTS LIST .................................................................. 5-6

MAIN BOARD ASSEMBLY(HR-J271MS/J471MS)<03> ........................... 5-6

MAIN BOARD ASSEMBLY(HR-J677MS/J777MS)<03> ......................... 5-11

AUDIO CONTROL HEAD BOARD ASSEMBLY <12> ............................ 5-16

DEMOD BOARD ASSEMBLY(HR-J777MS) <14> .................................. 5-16

MINI FRONT BOARD ASSEEMBLY(HR-J271MS/J471MS)<28> ........... 5-17

MINI OPE BOARD ASSEEMBLY(HR-J677MS/J777MS)<28> ............... 5-17

LOADING MOTOR BOARD ASSEMBLY <55> ....................................... 5-17

R.PAUSE BOARD ASSEMBLY(HR-J677MS/J777MS)<91> .................. 5-17

LT.BATTERY BOARD ASSEMBLY(HR-J271MS/J471MS)<93> ............. 5-17

LT.BATTERY BOARD ASSEMBLY(HR-J677MS/J777MS)<93> ............. 5-17

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

SECTION 1

DISASSEMBLY

1.3 DISASSEMBLY/ASSEMBLY METHOD

1.1 DISASSEMBLY FLOW CHART

This flowchart lists the disassembling steps for the cabinet

parts and P.C. boards in order to gain access to item(s) to

be serviced. When reassembling, perform the step(s) in re-

verse order. Bend, route and dress the flat cables as they

were originally laid.

1.2 HOW TO READ THE DISASSEMBLY AND ASSEMBLY

Note:

The bracketed ( ) WR of the connector symbol are as-

signed nos. in priority order and do not correspond to

those on the spare parts list.

(5) Adjustment information for installation

Top cover, Bracket

Front panel assembly

Drum assembly

Mechanism assembly

Main board assembly

Mini ope (Mini front) board assembly

Step/

LocNo.

Part Name

Fig.

No.

Point

Note

-----------------

Top cover

D1 2(S1a), (S1b)

Bracket

2(S1c)

Front panel assembly

D2 7(L2)

Drum assembly

D3 3(S3),

CON1(WR3a),

CN1(WR3b)

(Cleaner assy)

(L3c)

Mechanism assembly D4 2(S4a), (S4b),

(S4c), 2(L4),

CN1(WR4)

Main board assembly

D5 (S5), 6(L5a)

Mini ope board

(L5b),

assembly

CN7003(WR5)

[HR-J677MS/J777MS]

Mini front board

(L5b)

assembly

CN7001(WR5)

[HR-J271MS/J471MS]

-----------------

(1)

(2)

(3)

(4)

(5)

Step/

LocNo.

Part Name

Fig.

No.

Point

Note

Top cover,

D1 4(S1a),(S1b),3(L1a),

2(SD1a),(P1a),

CN1(WR1a),

Bracket

2(S1c)

(1) Order of steps in Procedure

When reassembling, perform the step(s) in the reverse order.

These numbers are also used as the identification (location) No.

of parts Figures.

(2) Part name to be removed or installed.

(3) Fig. No. showing procedure or part location.

(4) Identification of part to be removed, unhooked, unlocked,

released, unplugged, unclamped or unsoldered.

P= Spring, W= Washer, S= Screw, L= Locking tab, SD= Solder,

CN**(WR**)= Remove the wire (WR**) from the connector

(CN**).

-------------------

--------------------------

-------------------

-----------------

· When reattaching the Front panel assembly, make sure that

the door opener a of the Cassette holder assembly is low-

ered in position prior to the reinstallation.

· When reattaching the Front panel assembly, pay careful at-

tention to the switch lever not to make it touch the switch

knob b of the Main board assembly from the side.

(If the switch knob of the Main board assembly is damaged,

cassette loading is impossible.)

· Be careful not to damage the connector and wire etc. during

connection and disconnection.

When connecting the wire to the connector, be careful with

the wire direction.

· When it is required to remove the screws (S4a) retaining

the Mechanism assembly, please refer to the "Procedures

for Lowering the Cassette holder assembly"(See on page

1-2).

· When removing the Mechanism assembly only, unhook the

two spacers connecting it with the Main board assembly

with pliers from the back side of the Main board assembly

first, and then remove the Mechanism assembly.

· When reattaching the Mechanism assembly to the Main

board assembly, take care not to damage the sensors on

the Main board assembly (D3001: LED, Q3001/Q3002: Start

sensor, Q3002/Q3003: End sensor).

· When removing the PC Support from the bottom chassis,

take care not to damage the locking portion of the PC Sup-

port.