Jvc SRVS 20 EK Schematic

Page 2

Secfion Tflb

Important Safety Precautions
INSTRUCTIONS
1. DISASSEMBLV

1.1 HOW TO REMOVE THE MAJOR PARTS
1.1.1 Introduction

1.2 HOW TO READ THE DISASSEMBLY AND ASSEMBLY

1.3 DISCONNECTION OF CONNECTORS WIRES) ..
1.
1.
Disassembly Ilow chart
Disassembly/assembly method
1
1 Disassembly Ilow chart
2 Disassembl lassembl method .
1 HOW TO REMO E THE
.1 Disassembly Ilow chart

.2 Disassembly/assembly method .
SERVICE POSITIONS

4
5

1.5
1.5
1.6
1.6
1.7
1.7
1.8.1 Service position 1.
1.
1

1

1.
1.
1.
1.
1.

6
7
B

1

.2 Service osition
MECHANI M SERVICE MODE
9.1 How to set the "MECHANIS
0 CONNECTION
1 EMERGENCY DIS

1.9
11.1 Displaying the emergency informa
11.2 Clearing the emergency history
11.3 Emergency content description
11.4 Emergency detail inlormation
11.5 Emergency detail inlormation ,

2. MECHANISM ADJUSTMENT (VHS)
2.1 BEFORE STARTING REPAIRANDADJUSTMENT
.1 Precautions

3 Manualhv Removing the Cassette Tape .
.4 Jigs an Tools Required IorAdjustment.
.5 Maintenance and Ins ection .
REPLACEMENT OF M OR PARTS.
.1

2

mechanical pans)
2 2 How to Set the Mechanism Assembling Mode.

2 3 Cassette Holder Assembly

2 4 Pinch RollerArm Assembly"

2.5 Guide Ann Assembly and ress LeverAssembly
.26 Audio Control Head.
2.7 Loading Motor
2 8 Ca stan Moto
2 9 Po e Base Assembly (supply or take-up side
2 1 Rotary Encode
21 Clutch Unit ..

2 1

Link ever
Cassette G
Control Plate
Loading Arm 6

Cagstan Brake Assembly

Su Brake Assembly (ta e p
Main Brake Assembly (take-up side), ee
and Main Brake Assembly (supply side) .....

Tension Arm Assembly
Idler Lever, Idler Arm Assembly .
Stator Assembly .
Rotor Assembly .
Upper Drum Assembly.
COMPATIBILITY ADJUSTMENT .
Checking/Adjustment of FM Waveform Lineanty

Checking/A
CHANISM ADJUSTMENT (DV)
PREPARATION .
Precautions

SCREWS USED CABINET COMPONENT AND BOARD ASSEMBLIES
HOW TO REMOVE THE MAJOR PARTS

HOW TO REMOVE THE MAJOR PARTS

AJOR PARTS

Before Starting Disassembling (Phase matching between

Change Lever Assembly Direct Gear Clutch Gear and Coupling Gea
DD V P g
Take-up Lever, lsake-up Head and Control Plate Guide .

Tension Brake Assembly, Reel Disk (supply si e) an

. .1

. .2 Checking/Ad'ustment oi the Height and Tilt ol the Audio Control Head
. .3 Checking/A justment of the Audio Control Head Phase (X-Value)
. .4 Checking/Agjustment of the Standard Tracking Preset .
. .5 justment of the Tension Pole Position .

TABLE OF CONTENTS

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9.1
9.2 Tools Requir ]
9.3 Disassembly and Assembly Pro
9.4 Screws and Washers Used in Disassem y ssem y o
Mechanism Assembly
2.10 DISASSEMBLY/ASSEMBLY
2.10.1 Introduction
2.10.2 Mechanism Modes
2.11 MECHANISM TIMING CHART 2-24
2.12 MECHANISM ASSEMBLY/DISASSEMBLY PROCEDURE TABLE 2-25
2.13 DISASSEMBLY/ASSEMBLY 2-27
2.14 LIST OF PROCEDURES FOR DISASSEMBLY . 2-35
2.15 MECHANISM DISASSEMBLY/ASSEMBLY SHEET. 2-36
2.16 MECHANISM PHASE CHECK/ADJUSTMENT 2-38
2.17 POSITIONING THE TENSION POLE 2-39
2.18 COMPATIBILITY AND ERROR RATE ADJUSTMENTS 2-40
2.18.1 Preparation . 2-40
2.18.2 Adjustmen 2-40
2.18.3 Lineari adjustment . 2-41
2.18.4 PB switching point adjustment 2-41
2.18.5 Error rate adjustment 2-41
2.18.6 Error rate measuring method. 2-41
2.19 TAPE EJECTION

Secfion THE

3. ELECTRICAL ADJUSTMENT (VHS)
3.1 PRECAUTION ..
Required tes q p
2 Required adjustment tool

3 Colcr(cclour) bar signal,Co or (co our) ar pa ern
Switch settings and standard precautions
5 EVR Adjustment
1

2

1

Page

.1.
.1.
.1.
.1

.1.

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SERVO CIRCUIT.

Switching pom

Slow tracking preset
VIDEO CIRCU T

w

. D/A level .
.2 EE Y level
.3 PB Y level (S-VHS / VHS) .
.g REC color colour) level .
.6
.7

Video EC ( requency response) .
AUTO PICTURE initial setting .
DV EE Y level
AUDIO CIRCUIT
1 Audio REC FM

YSCON CIRCUIT [SR-VSZOE]
.1 Timerclock

E ECTRICAL ADJUSTMENT (DV)
3.6 PREPARATION.
3.6.1 Precautions
3.6.2 Equipment required for adjustment.
3.6.3 Tools required Ior adjustments .
3.6.4 Setup...

4. CHARTS AND DIAGRAMS
NOTES OF SCHEMATIC DIAGRAM
CIRCUIT BOARD NOTES ..
4 1 BOARD INTERCONNECTIONS
SWITCHING REGULATOR AND REGULATOR SCHEMATIC DIAGRAMS .
VIDEO/AUDIO SCHEMATIC DIAGRAM
SYSTEM CONTROL SCHEMATIC DIAG
SUB CPU SCHEMATIC DIAGRAM
TUNER SCHEMATIC DIAGRAM .
VIDEO IIO SWITCH SCHEMATIC
AUDIO l/O SCHEMATIC DIAGRAM
CONNECTION SCHEMATIC DIAGRA
3D DIGITAL/2M SCHEMATIC DIAGRA
TERMINAL SCHEMATIC DIAGRAM
DEMODULATOR SCHEMATIC DIAGR
S-SUB SCHEMATIC DIAGRAM
MDA SCHEMATIC DIAGRAM
PRE/REC SCHEMATIC DIAGRA
ON SCREEN SCHEMATIC DIAGRAM
DISPLAY, EJECT SW, LED/SW. JACK AND JOG SCHEMATIC DIAGRAMS
DV SYSTEM CONTROL SCHEMATIC DIAGRAM
DV MSD SCHEMATIC DIAGRAM
DV MAIN SCHEMATIC DIAGRAM
DV |/O SCHEMATIC DIAGRAM
DV V OUT SCHEMATIC DIAGRAM .
AUDIO AD/DA SCHEMATIC DIAGRAM .
DV DSP SCHEMATIC DIAGRAM .....
SWITCHING REGULATOR AND REGULATOR CIRCUIT BOARDS
3D DIGITAL/2M AND S-SUB CIRCUIT BOARDS
TERMINAL CIRCUIT BOARD
MAIN CIRCUIT BOARD .....
DEMODULATOR AND ON SCREEN CIRCUIT BOARD
DISPLAY, EJECT SW, JACK, LED/SW AND JOG CIRCUIT BOARDS
PRE/REC MDA CIRCUIT BOARD
DV MAIN CIRCUIT BOARD ..
FDP GRID ASSIGNMENT AND ANODE CONNECTION
REMOTE CONTROL SCHEMATIC DIAGRAM .
WAVEFORMS
VOLTAGE CHARTS
CPU PIN FUNCTIO
SYSTEM CONTROL
VIDEO BLOCK DIAGRAM(VHS)
AUDIO BLOCK DIAGRAM Q/HS .
SYSTEM CONTROL BLOC D G
VIDEO BLOCK DIAGRAM (DV)

PARTS LIST
5.1 PACKING AND ACCESSORY ASSEMBLY .
5.2 FINAL ASSEMBLY
5.3 MECHANISM ASSEMBLY VHS)
5.4 MECHANISM ASSEMBLY DV)
5.5 ELECTRICAL PARTS LIST

SW REGULATOR BOARD ASSEMBLY <01>
REGULATOR BOARD ASSEMBLY
MAIN BOARD ASSEMBLY <03) ..
3D DIGITAIJZM BOARD ASSEMBLY <05>
TERMINAL BOARD ASSEMBLY <06>
AUDIO CONTROL HEAD BOARD ASSEMBLY <12> .
DEMOD BOARD ASSEMBLY <14>
S-SUB BOARD ASSEMBLY <15>
DV PRE/REC MDA BOARD ASSEMBLY <16> .
ON SCREEN BOARD ASSEMBLY <17>.
EJECT SW BOARD ASSEMBLY <27>
SW/DISPLAY BOARD ASSEMBLY <2B>
JACK BOARD ASSEMBLY <36> ..
LED/SW BOARD ASSEMBLY <47> .
DV MAIN BOARD ASSEMBLY <50>
LOADING MOTOR BOARD ASSEMBLY <55> .
JOG BOARD ASSEMBLY <85>

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The following table lists the differing points between Models (SR-VSZOEK and SR-VSZOE) in this series.

SR-VSZOEK SR-VS20E
VIDEO SYSTEM PAL/NTSC PB ON PAL TV PAL/MESECAM(MANUAL)/NTSC PB ON PAL TV
TUNER (BROADCASTING STANDARD) | B/G, D/K
TUNER (STEREO DECODER) NICAM NICAM/A2
DISPLAY (LANG.) ENGLISH 3 LANGUAGE
TIMER (VCR PLUS+) VIDEO PLUS+ DELUXE SHOW VIEW DELUXE
nMER(VPS) NOTUSED USED

Page 23

2. In case of mechanical failure

If you cannot remove the cassette tape which is loaded be-

cause of any mechanical failure, manually remove it by tak-

ing the following steps.

(1) Unplug the power cable and remove the top cover, front
panel assembly and others so that the mechanism as-
sembly is visible. (See 1.3 DISASSEMBLY/ASSEMBLY
METHOD.)

(2) While keeping the tension arm assembly of the mecha-
nism assembly free from tension, pull the tape on the pole
base assembly (supply or take-up side) out of the guide
roller. (See Fig.2-1-3c.)

(3) Take the spring of the pinch roller arm assembly off the
hook of the press lever assembly, and detach it from the
tape. (See Fig.2-1-3d.)

(4) In the same way as in the electrical failure instructions in
2.1.3-1(4), remove the top guide.

(5) Raise the cassette tape cover. By keeping it in that posi-
tion, draw out the cassette tape case from the cassette
holder and take out the tape.

(6) By hanging the pinch roller arm assembly spring back
on the hook, take up the slack of the tape into the cas-
sette.

Pele base assembly (takevup side)
\

Pole base assembly ,.// '
(supply side)

Tensmn arm assembly 5,

H1] Take the spring
4/ off the hook, and

/., / detach it item the
tape.

/ l
Pinch roller arm assembly \

Gulde pble guam Press lever assembly

Fig. 2-1-3d

2.1.4 Jigs and Tools Required for Adjustment

Roller ttrlvel
FTU94002

Torque gauge

NC head postttbnmg teal
PTunglo PUJ48075-2

%

Back lsnslan cassette gauge Jig RCU
PUJ45076-2 PTusAazas

O

Allgnmsnl tape
(sP, stetretep. PAL)
MHPE

Alignment tape
tLP, stalrstep, PAL)
MHPE-L

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