JVC HR-S3902US, HR-S3912UC, HR-S3912US, HR-S5902US, HR-S5912UC Service Manual

SERVICE MANUAL

VIDEO CASSETTE RECORDER

HR-S3902U

HR-S5902U

For disassembling and assembling of MECHANISM ASSEMBLY, refer to the SERVICE MANUAL No.86700(MECHANISM ASSEMBLY).
Regarding SCHEMATIC DIAGRAMS, refer to the service manual No. 82946 (HR-S2902US).

SPECIFICATIONS

GENERAL

Power requirement AC 120 Vd, 60 Hz
Power consumption

Power on : 16 W
Power off 1.5 W

Temperature

Operating : 5 °C to 40 °C (41 °F to 104 °F)

Storage : –20 °C to 60 °C (–4 °F to140 °F)
Operating position :
Dimensions (WxHxD) 435 mmx94 mmx242 mm

Weight :
Format :
Maximum recording time

SP : 210 min. with ST-210 video cassette

EP : 630 min. with ST-210 video cassette

VIDEO/AUDIO

Signal system :

Recording/Playback
system

Signal-to-noise ratio 45 dB
Horizontal resolution

VHS 230 lines

S-VHS 400 lines
Frequency range

Normal audio 70 Hz to 10,000 Hz

Hi-Fi audio 20 Hz to 20,000 Hz
Input/Output :

:

:

:

:
:

:
:

:
:

S

, HR-S3912U

S

, HR-S5912U

S-VIDEO

(The specifications shown pertain specifically to the model HR-S5902US.)

Horizontal only

(17-3/16" x 3-3/4" x 9-3/4")

2.7 kg (5.9 lbs)
S-VHS/VHS NTSC standard

NTSC-type color signal and EIA
monochrome signal, 525 lines/
60 fields

DA-4 (Double Azimuth) head helical
scan system

RCA connectors (INx2, OUTx1)
S-video connectors (INx2, OUTx1)

COPYRIGHT © 2003 VICTOR COMPANY OF JAPAN, LTD

POWER

HR-S3902US, HR-S3912US, HR-S3912UC, HR-S5902US, HR-S5912US, HR-S5912UC V16S1,S15

S

, HR-S3912U

S

, HR-S5912U

FF

REW

24HR QUICK

REC LINK

PROGRAM

INSERT

A.DUB

TUNER

Tuning system :
Channel coverage

VHF Channels 2–13
UHF :
CATV :

RF output

TIMER

Clock reference :
Program capacity : 1-year programmable timer/

Memory backup for timer is not supported.

ACCESSORIES

Provided accessories :

Specifications shown are for SP mode unless specified otherwise.
E. & O.E. Design and specifications subject to change without
notice.

Frequency-synthesized tuner

:

Channels 14–69
113 Channels
Channel 3 or 4 (switchable; preset to :

Channel 3 when shipped) 75ohms,
unbalanced

Quartz
8 programs

Infrared remote control unit,
“AA” battery x 2,
S-video cable (4-pin),
RF cable (F-type)

C

,

C

No.82950

2003/03

TABLE OF CONTENTS

Section Title Page Section Title Page

Important Safety Precautions
INSTRUCTIONS

1. DISASSEMBLY

1.1 Manually removing the cassette tape ........................................ 1-1

1.2 Removing the major parts .......................................................... 1-2

1.2.1 How to read the procedure table.......................................... 1-2

1.2.2 Disassembly procedure ....................................................... 1-2

1.3 Emergency display function ....................................................... 1-4

1.3.1 Displaying the EMG information .......................................... 1-4

1.3.2 Clearing the EMG history ..................................................... 1-4

Details of the OSD display in the EMG display mode

1.3.3

1.3.4 EMG content description...................................................... 1-6

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

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

1.3.7 EMG detail information<3> .................................................. 1-8

1.4 Service position.......................................................................... 1-9

1.4.1 How to set the "Service position" ......................................... 1-9

1.5 Jig RCU mode............................................................................ 1-9

1.5.1 Setting the Jig RCU mode ................................................... 1-9

1.5.2 Setting the User RCU mode ................................................ 1-9

1.6 Mechanism service mode .......................................................... 1-9

1.6.1 How to set the "Mechanism service mode".......................... 1-9

1.6.2 How to exit from the "Mechanism service mode"................. 1-9

1.7 Maintenance and inspection .................................................... 1-10

1.7.1 Cleaning ............................................................................. 1-10

1.7.2 Lubrication ......................................................................... 1-10

Suggested servicing schedule for main components

1.7.3

2. MECHANISM

Refer to the SERVICE MANUAL No.86700(MECHANISM ASSEMBLY)

.................. 1-5

................. 1-10

4. CHARTS AND DIAGRAMS

Refer to the SERVICE MANUAL No.82946(HR-S2902US)

5. PARTS LIST

5.1 EXPLODED VIEW ...................................................................... 5-1

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

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

5.1.3 MECHANISM ASSEMBLY<M4> .......................................... 5-3

5.2 PARTS LIST ................................................................................ 5-4

PACKING AND ACCESSORY ASSEMBLY<M1> ........................... 5-4

FINAL ASSEMBLY<M2>................................................................. 5-4

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

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

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

ADV.JOG/SW BOARD ASSEMBLY<38> ...................................... 5-12

LOADING MOTOR BOARD ASSEMBLY<55>............................. 5-12

R.PAUSE BOARD ASSEMBLY<99>............................................. 5-12

3. ADJUSTMENT

3.1 Before adjustment ...................................................................... 3-1

3.1.1 Precaution ............................................................................. 3-1

3.1.2 Required test equipments .................................................... 3-1

3.1.3 Required adjustment tools ................................................... 3-1

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

3.1.5 Switch settings ..................................................................... 3-1

Manual tracking mode (Auto tracking ON/OFF) setting.................

3.1.6

EVR sdjustment .............................................................................

3.1.7

3.2 Mechanism compatibility adjustment ......................................... 3-2

3.2.1 Tension pole position............................................................ 3-3

3.2.2 FM waveform linearity .......................................................... 3-3

3.2.3 Height and tilt of the A/C head ............................................. 3-3

3.2.4 A/C head phase(X-value)..................................................... 3-4

3.3 Electrical Adjustment.................................................................. 3-4

3.3.1 Servo circuit ......................................................................... 3-4

3.3.1.1 Switching point ................................................................ 3-4

3.3.1.2 Slow tracking preset........................................................ 3-5

3.3.2 Video circuit.......................................................................... 3-5

3.3.2.1 EE Y/PB Y(S-VHS/VHS)level.......................................... 3-5

3-1
3-2

The following table indicates main different points between models HR-S3902US, HR-S3912US, HR-S3912UC, HR-S5902US, HR­S5912US and HR-S5912UC.

ITEM

MODEL

HR-S3902US

BODY COLOR MOLD-BLACK
RCU ILLUMI FUNCTION

NOT USED NOT USED NOT USED USED(GLOW) USED(GLOW) USED(GLOW)

PAINT-PURE SILVER PAINT-PURE SILVER

HR-S3912UCHR-S3912US HR-S5912USHR-S5902US HR-S5912UC

PAINT-BLACK

PAINT-PURE SILVER PAINT-PURE SILVER

FLYING ERASE HEAD NOT USED NOT USED NOT USED USED USED USED
ZERO FRAME EDIT NOT USED NOT USED NOT USED USED USED USED
INSERT NOT USED NOT USED NOT USED USED USED USED
AUDIO DUBBING NOT USED NOT USED NOT USED USED USED USED

Important Safety Precautions

cut close to connector

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.

v

Precautions during Servicing

1. Locations requiring special caution are denoted by labels and
inscriptions 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 service 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.

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
transformer primary lead wires are performed using crimp type
connectors, 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.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.1

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.

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
compliance with recognized codes pertaining to X-ray emission.
Consequently, when servicing these products, replace the cath­ode 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.

Fig.4

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

the wires fully into the connector.

Metal sleeve

Connector

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.

1.25

2.0

5.5

Fig.6

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

Not easily pulled free

Wire insulation recessed

more than 4 mm

Fig.7

Crimping tool

Crimped at approx. center

of metal sleeve

Conductors extended

1

S40888-01

v

d'

d

Chassis

Power cord,
primary wire

Region
USA & Canada
Europe & Australia

Grounding Impedance (Z)

Z 0.1 ohm
Z 0.5 ohm

≤
≤

AC inlet

Earth pin

Exposed accessible part

Milli ohm meter

Grounding Specifications

ab

c

V

Externally
exposed
accessible part

Z

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
externally 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
accessible 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’) be­tween soldered terminals, and between terminals and surrounding metallic parts. See table 1
below.

Fig. 8

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.

Fig. 9

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

AC Line Voltage

100 V
100 to 240 V
110 to 130 V

110 to 130 V
200 to 240 V

Region

Japan
USA & Canada

Europe & Australia R 10 MΩ/500 V DC

Region Load Z

Insulation Resistance (R)

≤

R 1 MΩ/500 V DC

≥≥

1 MΩ R 12 MΩ/500 V DC

≤

Table 1 Specifications for each region

Dielectric Strength

AC 1 kV 1 minute
AC 1.5 kV 1 miute
AC 1 kV 1 minute

AC 3 kV 1 minute
AC 1.5 kV 1 minute

(Class 2)
(Class 1)

Clearance Distance (d), (d')

≤

d, d' 3 mm

≤

d, d' 4 mm

≤

d, d' 3.2 mm

≤

d 4 mm

≤

d' 8 mm (Power cord)

≤

d' 6 mm (Primary wire)

a, b, cLeakage Current (i)AC Line Voltage

100 V

110 to 130 V

110 to 130 V
220 to 240 V

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

Japan

USA & Canada

Europe & Australia

Table 2 Leakage current specifications for each region

1 kΩ

0.15 µF

1.5 kΩ

2 kΩ

50 kΩ

2

≤

i 1 mA rms Exposed accessible parts

≤

i 0.5 mA rms

≤

i 0.7 mA peak

≤

i 2 mA dc

≤

i 0.7 mA peak

≤

i 2 mA dc

Exposed accessible parts

Antenna earth terminals

Other terminals

S40888-01

SECTION 1

Screw(a)

Screw(a)

Top frame

Cassette tape

Cassette holder

Side frame(R)

Side frame(L)

Hook(a)

Hook(b)

DISASSEMBLY

1.1 Manually removing the cassette tape

If you cannot remove the cassette tape which is loaded be­cause of any electrical or mechanical failures, manually remove
it by taking the following steps.

(1) Unplug the power cord plug from the power outlet.
(2) Refer to the disassembly procedure of the VCR and perform

the disassembly of the major parts before removing the
mechanism assembly. (See Fig. 1-1a.)

Fig. 1-1a

Tension arm assembly

Pole base assembly

Pinch roller arm assembly

(3) Unload the pole base assembly by manually turning the gear

of the loading motor until the pole base assembly is hidden
behind the cassette lid. In doing so, hold the tape by the hand
to keep the slack away from any grease. (See Fig. 1-1b.)
In case of mechanical failures, while keeping the tension arm
assembly free from tension, pull out the tape on the pole
base assembly. Take the spring(a) of the pinch roller arm

assembly off the hook, and detach it from the tape.
(4) Remove the screw (a) of the side frame (L/R).
(5) Hold the slack tape and cassette cover together, lift the cas-

sette tape, top frame, cassette holder and side frames (L,

R) together from the rear and remove them by dis-engaging

the hooks (a) and (b).

Spring(a)

Fig. 1-1b

Fig. 1-1c

(6) Take up the slack of the tape into the cassette. This com-

pletes removal of the cassette tape.

Direction of unloading

1-1

1.2 Removing the major parts

1.2.1 How to read the procedure table

This table shows the steps for disassembly of the externally
furnished parts and board assemblies. Reverse these steps
when re-assembling them.

<Example>

Step/

Loc No.

Part Name

[1] Top cover, 1-3a

Bracket 2(S1c)

(1) (2) (3) (4) (5)

Fig.
No.

Point Note

4(S1a),(S1b),3(L1a), <Note 1a>
2(SD1a),(P1a),(W1a),
CN1(WR1a),

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

(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**).

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

1.2.2 Disassembly procedure

Step/

Loc No.

Part Name

[1] Top cover 1-2-2d 3(S1a), 2(L1a)
[2] Front panel assembly 1-2-2d 2(S2a), 2(L2a), 2(L2b), <Note 2a>

(ADV.Jog board assembly)

[3] Mechanism assembly 1-2-2d CN2001(WR3a), <Note 2a>

(Drum Shield) (S3f), (L3a)
(Drum assembly) 1-2-2b CN1(WR3b),

[4] Main board assembly 1-2-2d (L4a), (L4b), (L4c),

Fig.
No.

Point Note

1-2-2a 3(L2c) <Note 2b>

CN7001(WR2a)

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

3(S2b),
Knob assembly

(S3a), (S3b) <Note 3a>

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

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

<Note 3b>
<Note 3c>

1-2-2c (S3x), (S3y), (S3z)

(L4d)

<Note 2a>

• Be careful not to damage the connector and wire etc. during
connection and disconnection.

• When connecting the flat wire to the connector, be careful with
the flat wire direction.

<Note 2b>

• When reattaching the Front panel assembly, make sure that
the door opener of the Side frame (R) is lowered in position
prior to the reinstallation.

• When reattaching the Front panel assembly, pay careful atten­tion to the switch lever of the Front panel assembly not to make
it touch the switch knob of the Main board assembly from the
side.

• When reattaching the Front panel assembly, lift the Cassette
door slightly.

Door
opener

Side
frame(R)

Switch
knob

Switch
lever

Fig. 1-2-2a

<Note 3a>

• When reattaching the Mechanism assembly , secure the screws
(S3a to S3b) in the order of a, b.

<Note 3b>

• When reattaching the Mechanism assembly, be sure to align
the phase of the Rotary encoder on the Main board assembly.

• When reattaching the Mechanism assembly, set the “Mecha­nism assembling mode”. (See “section 2 mechanism”.)

• When reattaching the Mechanism assembly to the Main board
assembly , take care not to damage the sensors and switch on
the Main board assembly.

<Note 3c>

• When reattaching the Drum assembly, secure the screws (S3x
to S3z) in the order of x, y, z.

(S3x)

Mechanism
assembly

(S3y)

(S3z)

Drum
assembly

<Note 3b>

(S3y)

<NOTE>
Attach the Drum assembly appropriately,
since the installation state of the Drum assembly
influences the FM WAVEFORM LINEARITY
greatly.

(S3x)

(S3z)

HOOK

Fig. 1-2-2b

• When handling the drum assembly alone, hold it by the motor
or shaft. Be careful not to touch other parts, especially the video
heads. Also take care not to damage the connectors.

Shaft

Motor

Video heads

Fig. 1-2-2c

1-2