JVC HRS6851EU - Service Manual Immediate Download

SERVICE MANUAL

No. 82856

May 2001

HR-S6850EU,S6851EU,S6852EU,S6855EK

SPECIFICATIONS (The specifications shown pertain specifically to the model HR-S6850EU/S6851EU/6852EU)

VIDEO CASSETTE RECORDER

Printed in Japan

This service manual is printed on 100% recycled paper.

HR-S6850EU,S6851EU,S5852EU,S6855EK

No.

82856

VICTOR COMPANY OF JAPAN, LIMITED

VIDEO DIVISION

S40894

GENERAL

Power requirement

: AC 220 V 240 V ` , 50 Hz/60 Hz

Power consumption

Power on

: 22 W

Power off

3.8 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

: 3.6 kg

Format

: S-VHS/VHS PAL standard

Maximum recording time

(SP)

: 240 min. with E-240 video cassette

(LP)

: 480 min. with E-240 video cassette

(EP)

: 720 min. with E-240 video cassette

VIDEO/AUDIO

Signal system

: PAL-type colour signal and CCIR

monochrome signal, 625 lines 50 fields

Recording system

: DA4 (Double Azimuth) head helical scan system

Signal-to-noise ratio

: 45 dB

Horizontal resolution

(SP/LP)

: 250 lines (VHS)

400 lines (S-VHS)

(EP)

: 220 lines (VHS)

350 lines (S-VHS)

Frequency range

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

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

Input/Output

: 21-pin SCART connectors:

IN/OUT x 1, IN/DECODER x 1

RCA connectors:

VIDEO IN x 1, AUDIO IN x 1, AUDIO OUT x 1

S-Video connector: IN x 1

TUNER/TIMER

TV channel storage capacity

: 99 positions (+AUX position)

Tuning system

: Frequency synthesized tuner

Channel coverage

: VHF 47 MHz 89 MHz/

104 MHz 300 MHz/

302 MHz 470 MHz

UHF 470 MHz 862 MHz

Aerial output

: UHF channels 22 69 (Adjustable)

Memory backup time

: Approx. 10 min.

ACCESSORIES

Provided accessories

: RF cable,

Infrared remote control unit,

"R6" battery x 2

Specifications shown are for SP mode unless otherwise specified.

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

notice.

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 D/A level .......................................................................... 3-2

3.3.2 EE Y/PB Y (S-VHS/VHS) level ......................................... 3-2

3.3.3 REC color (colour) level ................................................... 3-3

3.3.4 Video EQ (Frequency response) ..................................... 3-3

3.3.5 Auto picture initial setting ................................................. 3-4

3.4 Audio circuit ............................................................................ 3-4

3.4.1 Audio REC FM ................................................................. 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 MAIN (VIDEO/AUDIO) SCHEMATIC DIAGRAM .................. 4-5

4.3 MAIN (ON SCREEN) SCHEMATIC DIAGRAM .................... 4-7

4.4 MAIN (SYSCON) SCHEMATIC DIAGRAM .......................... 4-9

4.5 MAIN (SW.REG) SCHEMATIC DIAGRAM ......................... 4-11

4.6 MAIN (TUNER) SCHEMATIC DIAGRAM ........................... 4-13

4.7 MAIN (SW/DISPLAY), S-JACK AND ADV.JOG

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

4.8 MAIN (MAIN TERMINAL) SCHEMATIC DIAGRAM ............ 4-17

4.9 2D DIGITAL SCHEMATIC DIAGRAM ................................. 4-19

4.10 TERMINAL (S-SUB) SCHEMATIC DIAGRAM ................. 4-21

4.11 TERMINAL (I/O) SCHEMATIC DIAGRAM ....................... 4-23

4.12 DEMODULATOR SCHEMATIC DIAGRAM ...................... 4-25

4.13 2D DIGITAL AND DEMODULATOR CIRCUIT BOARDS . 4-27

4.14 TERMINAL CIRCUIT BOARD ......................................... 4-28

4.15 MAIN CIRCUIT BOARD ................................................... 4-29

4.16 REMOTE CONTROLLER SCHEMATIC DIAGRAM ......... 4-32

4.17 FDP GRID ASSIGNMENT AND ANODE CONNECTION 4-33

4.18 WAVEFORMS .................................................................. 4-34

4.19 VOLTAGE CHARTS ......................................................... 4-36

4.20 CPU PIN FUNCTION ....................................................... 4-37

4.21 SYSTEM CONTROL BLOCK DIAGRAM ......................... 4-39

4.22 VIDEO BLOCK DIAGRAM ............................................... 4-41

4.23 AUDIO BLOCK DIAGRAM ............................................... 4-45

5. PARTS LIST

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

5.2 FINAL ASSEMBLY <M2> .................................................... 5-2

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

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

MAIN BOARD ASSEMBLY <03> ............................................... 5-6

2D DIGITAL BOARD ASSEMBLY <05> ................................... 5-13

TERMINAL BOARD ASSEMBLY <06> ................................... 5-14

A/C HEAD BOARD ASSEMBLY <12> ..................................... 5-16

DEMOD BOARD ASSEMBLY <14> ........................................ 5-16

S.JACK BOARD ASSEMBLY <36> ......................................... 5-16

ADV.JOG BOARD ASSEMBLY <38> ....................................... 5-16

LOADING MOTOR BOARD ASSEMBLY <55> ....................... 5-16

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 set the "Service position" ..................................... 1-4

1.5 Mechanism service mode ..................................................... 1-4

1.5.1 How to set the "Mechanism service mode" ..................... 1-4

1.6 Jig RCU mode ....................................................................... 1-4

1.6.1 Setting the Jig RCU mode ............................................... 1-4

1.6.2 Setting the User RCU mode ............................................ 1-4

1.7 Servicing items related to video navigation .......................... 1-4

1.8 Emergency display function .................................................. 1-5

1.8.1 Displaying the EMG information ...................................... 1-5

1.8.2 Clearing the EMG history ................................................ 1-5

1.8.3 EMG content description ................................................. 1-6

1.8.4 EMG detail information <1> ............................................. 1-7

1.8.5 EMG detail information <2> ............................................. 1-8

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 A/C 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 FM waveform linearity ................................................... 2-16

2.3.2 Height and tilt of the A/C head ...................................... 2-17

2.3.3 A/C head phase (X-value) ............................................. 2-17

2.3.4 Standard tracking preset ............................................... 2-18

2.3.5 Tension pole position ..................................................... 2-18

TABLE OF CONTENTS

Section

Title

Page

Section

Title

Page

HR-S6850EU

HR-S6851EU

HR-S6852EU

HR-S6855EK

VIDEO SYSTEM

PAL/MESECAM(MANUAL) PAL/MESECAM(MANUAL)

PAL/MESECAM(MANUAL)

PAL/NTSC ON PAL TV

/NTSC ON PAL TV

BROADCASTING STANDARD

B/G,D/K

STEREO DECODER

NICAM/A2

NICAM

RF OUT SYSTEM [INITIAL]

G,K

VCR PLUS+

SHOWVIEW DELUXE

VIDEOPLUS+ DELUXE

VPS(AUTO)

USED

NOT USED

INITIAL (TIMER)

GER,AUS,SWISS:ON,

OFF

OTHER:OFF

CABLE BOX OR DBS. BOX OR SAT CTL

READY

USED

LANGUAGE [INITIAL]

13 LANG. [E]

ENG

(ON SCREEN DISPLAY)

GOST

USED

NOT USED

FRONT PANEL COLOR

PURE SILVER

BLACK

PURE SILVER

WINDOW COLOR

SMOKE LIGHT GRAY

GREEN

SMOKE PINK

CLEAR

CABLE MOUSE

OPTION

PROVIDED

The following table lists the differing points between Models ( HR-S6850EU, HR-S6851EU, HR-S6852EU and HR-S6855EK) 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

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

[1]

Top cover,

D1 4(S1a), (S1b)

Bracket

2(S1c)

[2]

Front panel assembly

D2 CN7001(WR2a),

CN916(WR2b),

4(L2a), 3(L2b)

ADV. Jog board assembly

2(S2a)

S Jack board assembly

2(S2b)

[3]

Drum assembly

D3 CON1(WR3a),

CN1(WR3b),

(S3a), (S3b), (S3c)

(Inertia plate)

4(L3a)

(Roller arm assy)

(P3), (L3b)

[4]

Mechanism assembly D4 CN2001(WR4a),

(S4a),(S4b),

(S4c), (S4d)

[5]

Main board assembly

D5 7(L5a),

(S5a), 3(S5b)

[6]

Bottom cover

D6 2(L6a), 9(L6b)

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,

ADV. Jog board assembly,

S Jack board assembly

Drum assembly

Mechanism assembly

Main board assembly

Bottom cover

[1]

[2]

[3]

[4]

[5]

[6]

Step/

LocNo.

Part Name

Fig.

No.

Point

Note

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

(1)

(2)

(3)

(4)

(5)

Step/

LocNo.

Part Name

Fig.

No.

Point

Note

[1]

Top cover,

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

2(SD1a),(P1a),(W1a),

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.

· 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 to S4b) re-

taining the Mechanism assembly, please refer to the "Pro-

cedures for Lowering the Cassette holder assembly"(See

on page 1-2).

· When reattaching the Mechanism assembly to the Main

board assembly, take care not to damage the sensors and

switch on the Main board assembly.

· 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.

· The wire (WR4a) has excess length that may be loose, as it

is quite long. After inserting the wire and connectors, the

loose portion of the wire should be taken up and accommo-

dated between the A/C head base and the main deck.

When removing the bottom cover, push down the two tabs

(L6a) to slide the bottom cover.