JVC HRJ686M - Service Manual Immediate Download

SERVICE MANUAL

No. 82785

July 2000

HR-J686EN/J686M

ESPECIFICACIONES (The specifications shown pertain specifically to the model HR-J686EN)

VIDEO CASSETTE RECORDER

Printed in Japan

VICTOR COMPANY OF JAPAN, LIMITED

VIDEO DIVISION

S40894

This service manual is printed on 100% recycled paper.

HR-J686EN/J686M

No.

82785

VIDEO (MONO)L--AUDIO--R

SP/LP

REW

POWER

VCR

REC

PAUSE

STOP/EJECT

PLAY

N-PAL NTSC

TV PROG +

TV PROG

VCR

START

DEBUT

STOP

FIN

DATE

PROG

TV/VCR

0000

DAILY/QTDN.

AUX

WEEKLY/HEBDO

PROG

AUDIO

CABLE

/SAT

123

EXPRESS

PQ000000

VPS/PDC

ENTER/ENTREE

30 SEC

mULTImARQUE

GENERALIDADES

Alimentación

: 110 V 220 V` - CA, 50/60 Hz

Consumo

Alimentación conectada

: 19 W

Alimentación desconectada : 2,5 W

Temperatura

De funcionamiento : 5°C a 40°C (41°F a 104°F)

De almacenamiento : 20°C a 60°C (4°F a140°F)

Posición de funcionamiento : Unicamente horizontal

Dimensiones (An x Al x Pr) : 400 mm x 94 mm x 281 mm

Peso

: 3,5 kg

Formato

: Norma VHS PAL-N/NTSC

Tiempo máximo de grabación

: 240 minutos con un videocassette E-240 (PAL-N)

: 160 minutos con un videocassette T-160 (NTSC)

: 480 minutos con un videocassette E-240 (PAL-N)

: 480 minutos con un videocassette T-160 (NTSC)

VIDEO/AUDIO

Sistema de señales

: Señal de color tipo PAL-N y señales monocromas

EIA, 625 líneas/50 campos, Señales cromáticas

NTSC y señales monocromas EIA, 525 líneas /60

campos (solo para reproducción)

Sistema de grabación/

reproducción

: Sistema de exploración helicoidal de 4 cabezas

DA-4 (doble acimut)

Relación señal a ruido

: 45 dB

Resolución horizontal

: 240 líneas (PAL-N)

: 230 líneas (NTSC)

Gama de frequencia

Audio nomal

: 70 Hz a 10,000 Hz

Audio de alta

fidelida

: 20 Hz a 20,000 Hz

Entrada/Salida

: Conectores RCA (IN x 1, OUT x 1)

SINTONIZADOR

Sistema de sintonía

: Sintonizador de frecuencia

sintetizada

Cobertura de canales

VHF

: Canales 213

UHF

: Canales 1469

CATV

: 113 Canales

Salida de RF

: Salida de RF: Canal 3 ó 4

(conmutable; preajustado en fábrica

al canal 3) 75

asimétrica

TEMPORIZADOR

Referencia de reloj

: Cuarzo

Capacidad de

programación

: Temporizador programable para 1

año/8 programas

Tiempo de protección

de la memoria

: Aprox. 6 meses

Cifra estimada pasada en la

pila nueva suministrada; el

rendimiento real puede ser diferente.

ACCESORIOS

Accesorios suministrados

: Cable RF,

Unidad e control remoto por

infrarrojos,

Pila de litio CR2025,

Pila "AA" x 2

A menos que se especifique lo contrario, las especificaciones dadas son

para el modo SP.

El diseño y las especificaciones se encuentran sujetos a cambios sin previo

aviso.

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) ................................ 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

TABLE OF CONTENTS

Section

Title

Page

Section

Title

Page

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

3.1.5 EVR Adjustment ............................................................... 3-1

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 DEMODULATOR CIRCUIT ................................................... 3-3

3.4.1 Input level ......................................................................... 3-3

3.4.2 Stereo VCO ...................................................................... 3-3

3.4.3 Stereo filter ....................................................................... 3-3

3.4.4 Separation - 1 .................................................................. 3-3

3.4.5 Separation - 2 .................................................................. 3-4

3.4.6 SAP VCO ......................................................................... 3-4

3.5 SYSCON CIRCUIT ............................................................... 3-4

3.5.1 Timer clock ....................................................................... 3-4

4. CHARTS AND DIAGRAMS

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

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

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

4.2 VIDEO/AUDIO SCHEMATIC DIAGRAMS ............................. 4-5

4.3 SYSTEM CONTROL SCHEMATIC DIAGRAM ..................... 4-7

4.4 SWITCHING REGULATOR SCHEMATIC DIAGRAM .......... 4-9

4.5 TUNER/DEMOD SCHEMATIC DIAGRAM .......................... 4-11

4.6 DISPLAY, MINI FRONT AND SHUTTLE SCHEMATIC

DIAGRAMS ......................................................................... 4-13

4.7 BS CONNECTION AND LITHIUM BATTERY

SCHEMATIC DIAGRAMS ................................................... 4-15

4.8 TERMINAL SCHEMATIC DIAGRAM .................................. 4-16

4.9 MAIN, A/C HEAD, MINI FRONT, SHUTTLE AND

LOADING MOTOR CIRCUIT BOARDS .............................. 4-17

4.10 FDP GRID ASSIGNMENT AND ANODE CONNECTION 4-21

4.11 REMOTE CONTROL SCHEMATIC DIAGRAM ................ 4-22

4.12 VOLTAGE CHARTS ......................................................... 4-23

4.13 SYSTEM CONTROL BLOCK DIAGRAM ......................... 4-25

4.14 VIDEO BLOCK DIAGRAM ................................................ 4-27

4.15 AUDIO BLOCK DIAGRAM ................................................ 4-29

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 <03> ............................................... 5-6

AUDIO CONTROL HEAD BOARD ASSEMBLY <12> .............. 5-11

MINI FRONT BOARD ASSEMBLY(HR-J686M)<28> ...............5-11

LOADING MOTOR BOARD ASSEMBLY <55> ........................5-11

SHUTTLE BOARD ASSEMBLY(HR-J686EN) <85> ................ 5-12

LITHIUM BATTERY BOARD ASSEMBLY <93> ...................... 5-12

HR-J686EN

HR-J686M

SHUTTLE DIAL

NOT USED

USED

VIDEO SYSTEM

PAL-N/NTSC

PAL-M/NTSC

SQPB

NTSC ONLY

NTSC, PAL-M

LEVEL METER

USED

NOT USED

POWER PLUG

IRAM

SEV 2PIN

COSMETIC

LIGHT SILVER

CHAMPAGNE

ANT. CABLE

F-F

F-F/300ohm

The following table lists the differing points between Models (HR-J686EN and HR-J686M) in this series.

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 cabi-

net parts and P.C. boards in order to gain access to

item(s) to be serviced. When reassembling, perform the

step(s) in reverse order. Bend, route and dress the flat

cables as they were originally laid.

1.2 HOW TO READ THE DISASSEMBLY AND ASSEMBLY

· 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 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.)

· 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: Start sen-

sor, Q3002: End sensor).

· When removing the PC Support from the bottom chassis,

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

port.

· When removing the bottom cover, push down the two tabs

(L6a) to slide the bottom cover.

Top cover, Bracket

Front panel assembly

Drum assembly

Bottom cover

Mechanism assembly

Mini front board assembly

Main 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)

CN7001(WR2)

[HR-J686EN]

Drum assembly

D3 3(S3)

CON1(WR3a),

CN1(WR3b)

(Cleaner assy)

(L3c)

Mechanism assembly D4 2(S4a),(S4b),(S4c), <Note 2a>

2(L4), CN1(WR4)

Mini front board

(L5a),

assembly

CN7001(WR5)

[HR-J686M]

Main board assembly

D5 (S5a), (S5b), 6(L5b)

Bottom cover

D6 2(L6a),6(L6b),3(L6c) <Note 6>

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

(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**).

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

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

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