Daewoo DVST7J3-4J3-2J3, DVST7E3-4E3-2E3, DVST7W3-4W3-2W3, DVST7L3-4L3-2L3, DVST7D3-4D3-2D3 User Manual

S/M No. : VTG7J3DET0

Service Manual

Video Cassette Recorder

ALL T -MECHA (Hi-Fi/MONO)

Model: (PAL/SECAM MODELS)
D VST7C3/4C3/2C3 Series
D VST7E3/4E3/2E3 Series
D VST7M3/4M3/2M3 Series
D VST7J3/4J3/2J3 Series
D VST7D3/4D3/2D3 Series
D VST7T3/4T3/2T3 Series
D VST7W3/4W3/2W3 Series
D VST7L3/4L3/2L3 Series

DVST7L3

DVST7E3

2

DVST7C3

DVST7B3

D AEW OO ELECTR ONICS CO., LTD.

http : //svc.dwe .co.kr

Apr . 2002

TABLE OF CONTENTS

SAFETY&PRECAUTIONS................................................................................................ 2

EXTERNAL VIEWS......................................................................................................... 4

FRONT VIEWS FUNCTION.................................................................................................................... 4

REAR VIEWS FUNCTION...................................................................................................................... 6

ELECTRICAL ADJUSTMENT............................................................................................ 7

SPECIFICATIONS ......................................................................................................... 8

CIRCUIT INFORMATION............................................................................................... 9

INTERCONNECT WIRING DIAGRAM..................................................................................................... 9

POWER CIRCUIT DIAGRAM................................................................................................................. 10

POWER BLOCK DIAGRAM.................................................................................................................. 12

SYSCON CIRCUIT DIAGRAM............................................................................................................... 13

SERVO & SYSCON BLOCK DIAGRAM.................................................................................................. 15

A/V & SECAM COLOR CIRCUIT DIAGRAM........................................................................................... 16

VIDEO PLAYBACK/RECORD PATH FOR PAL.......................................................................................... 18

HIFI & SW CIRCUIT DIAGRAM.............................................................................................................. 19

PIF CIRCUIT DIAGRAM........................................................................................................................ 21

COMPONENTS LOCATION GUIDE ON PCB BOTTOM VIEW............................................ 23

PCB MAIN.......................................................................................................................................... 23

DISASSEMBLY ............................................................................................................. 24

PACKING ASS’Y ................................................................................................................................. 24

FRONT PANEL ASSEMBLY ................................................................................................................... 25

INSTRUMENT DISASSEMBLY ................................................................................................................. 29

ELECTRICAL PARTS LIST ............................................................................................... 30

PCB MAIN AS .................................................................................................................................... 30

1

SAFETY & PRECAUTIONS

SAFETY CHECK AFTER SERVING

Examine the area surrounding the repaired location for damage or deterioration. Observe that screw, parts and wires
have been returned to original positions. Afterwards, perform the following tests and conform the specified values in order
to verify compliance whit safety standards.

1. Insulation resistance test
Confirm the specified insulation resistance between power cord plug prong and externally exposed parts of the set
(RF terminals, antenna terminals, video and audio input and output terminals, microphone jacks, earphone jacks, etc.)
is

greater than values given in table 1 below.

2. Dielectric strengthen test
Confirm specified dielectric strengthen between power cord
plug prongs and exposed accessible parts of the set
(RF terminals, antenna terminals, video and audio input output
terminals, microphone jack, ear phone jacks, etc.)
is greater than values given table 1.

3. Clearance distance
When replacing primary circuit component, confirm specified clearance distance (d), (d
and between terminals and surrounding metallic parts. See table below.

Rating for selected areas

AC Line Voltage Region

100V Japan

110 to 130V

* 110 to 130V

200 to 240V

* : Class model only

USA & Canada

Latin America

Europe

Australia

Insulation

Resistance

>1MΩ

/500V DC

- 900V AC 1min.

>10MΩ

/500V DC 4kV AC 1min.

NOTE

This table is unofficial and for reference only. Be sure to confirm the precise values for your
particular country and locality

Dielectric

Strength

1kV AC 1min.

’

) between soldered terminals,

Clearance

Distance(d),(d)

>

3

>

3.2

>

6(d)

>

8(d')

(a :Power cord)

2

4. Leakage current test
Confirm specified or lower leakage current between B(earth
ground, power cord plug prongs) and externally exposed accessi­ble parts (RF terminals, antenna terminals, video and audio input
output terminals, microphone jacks, earphone jacks, etc.)
Measuring method:(Power ON) Insert load Z between B(earth
ground, power cord plug prongs) and exposed accessible parts.
Use on AC voltmeter to measure across both terminals of load Z.
See figure2 and following table.

Leakage current ratings for selected are as

SAFETY & PRECAUTIONS

AC Line Voltage Region Load Z

100V Japan

1k

Ω

110 to 130V USA &Canada

110 to 130V
200 to 240V

Europe

Australia

1k

2k

50k

15kmF

Ω

Ω

Ω

NOTE

This table is unofficial and for reference only. Be sure to confirm the precise values
for your particular country and locality.

Leakage Cur-

rent(i)

i

<

1 mArms

i

<

0.5mArms Exposed accessible parts

i

<

0.7mA peak

i

<

2mAdc

i

<

0.7mA peak

i <

1mAdc

Clearance Distance(d),(d’)

Exposed accessible parts

Antenna earth terminals

Other terminals

3

EXTERNAL VIEWS

1. FRONT VIEWS FUNCTION

DVST7C3 FRONT VIEW

DVST7E3 FRONT VIEW

DVST7L3 FRONT VIEW

DVST7M3 FRONT VIEW

4

DVST7J3 FRONT VIEW

DVST7D3 FRONT VIEW

EXTERNAL VIEW

DVST7B3 FRONT VIEW

DVST8T3 FRONT VIEW

DVST8W3 FRONT VIEW

POWER REWIND / REVIEW

STOP / EJECT FAST FORWARD / CUE
RECORD PLAY BACK
FRONT VIDEO/AUDIO INPUT JACK CHANNEL UP / DOWN

5