Daewoo DVST7C3, DVST2C3, DVST4C3, DVST2E3, DVST7M3 Service Manual

Service Manual

S/M No. : VTG7J3DET0

Apr . 2002

D AEW OO ELECTR ONICS CO., LTD .

http : //svc.dwe .co.kr

Video Cassette Recorder

Model: (PAL/SECAM MODELS)
ST263 (DVST7L3)

ALL T -MECHA (Hi-Fi/MONO)

DVST7L3

2

2

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

’

) between soldered terminals,

and between terminals and surrounding metallic parts. See table below.

Rating for selected areas

* : Class model only

AC Line Voltage Region

Insulation

Resistance

Dielectric

Strength

Clearance

Distance(d),(d)

100V Japan

>1MΩ

/500V DC

1kV AC 1min.

>

3

110 to 130V

USA & Canada

- 900V AC 1min.

>

3.2

* 110 to 130V

200 to 240V

Europe

Australia

Latin America

>10MΩ

/500V DC 4kV AC 1min.

>

6(d)

>

8(d')

(a :Power cord)

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

NOTE

3

SAFETY & PRECAUTIONS

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

AC Line Voltage Region Load Z

Leakage Cur-

rent(i)

Clearance Distance(d),(d’)

100V Japan

1k

Ω

i

<

1 mArms

Exposed accessible parts

110 to 130V USA &Canada

15kmF

1k

Ω

i

<

0.5mArms Exposed accessible parts

110 to 130V
200 to 240V

Europe

Australia

2k

Ω

i

<

0.7mA peak

i

<

2mAdc

Antenna earth terminals

50k

Ω

i

<

0.7mA peak

i <

1mAdc

Other terminals

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

NOTE

4

1. FRONT VIEWS FUNCTION

DVST7C3 FRONT VIEW

DVST7E3 FRONT VIEW

DVST7L3 FRONT VIEW

DVST7M3 FRONT VIEW

EXTERNAL VIEWS

EXTERNAL VIEWS

2. REAR VIEWS FUNCTION

MONO 1 SCART TYPE REAR VIEW

MONO 2 SCART TYPE REAR VIEW

HI-FI 2 SCART TYPE REAR VIEW

MONO RCA TYPE REAR VIEW

HI-FI RCA TYPE REAR VIEW

6

7

ELECTRICAL ADJUSTMENT

1. PLAYBACK PHASE

ADJUSTMENT PROCEDURE

1. Play back the test tape. (DP-2)

2. Set the oscilloscope to the CHOP mode. Connect CH1 to the SW PULSE (PIN 4 of P502)

3. Connect CH2 to the ENVE signal (PIN5 of P502)

4. Insert PATH JIG and press "REC" button on the remote control.

5. Check the position of the V-sync from the rising edge of the SW pulse.

(Standard : 6.5H ± 0.5H)

ITEM MODE

ADJUSTMENT

POINT

CHECK POINT

TEST

EQUIPMENT

TEST
TAPE

INPUT

SIGNAL

6.5H

ADJUSTMENT

PLAY [REC] BUTTON

PIN 4 & PIN 5

OF P502

OSCILLOSCOPE DP-2 NO SIGNAL

ADJUSTMENT PARTS MEASURING POINT

PCB : MAIN - TOP VIEW

TMI
BLOC

PRE­AMP

P502

TO PATH JIG

OSCILLOSCOPE

CH1 CH2

PATH JIG

8

SPECIFICATIONS

CHANNEL COVERAGE

INPUT/OUTPUT JACK TYPE

GENERAL

Power Requirement
Power Consumption
Temperature

Operating position
Dimensions (W x H x D)
Weight
Format
Tape Width
Tape Speed

Maximum Recording Time with full-size cas­sette

AC 230V, 50Hz
Max. 17W (in REC mode)
5×C ~ 35×C (Operating)

-20×C ~ 60×C
Horizontal only
360 x 90 x 288 (mm)
Approx. 3.85 Kg
VHS standard

12.65mm
(SP) : 23.39mm/sec
(LP) : 11.70mm/sec
(SP) :240min, with E-240 video cassette
(LP) :480min, with E-240 video cassette

VIDEO

Signal system
Recording system

Input
Output
Signal-to-Noise ratio

Horizontal resolution

PAL/SECAM colour and CCIR monochrome signals, 625 lines/50 fields
Rotary two-head helical scan with a slant double-azimuth combination video
head

1.0Vp-p, 75ohms, unbalanced

1.0Vp-p, 75ohms, unbalanced
45dB (Rhode & Schwarz noise meter) with NETTETE IMAGE control at cen­ter position
240 lines with NETTETE IMAGE control at center position

AUDIO

Recording system
Input
Output

Frequency Range
Signal to Noise Ratio
Audio Distortion

Longitudinal track

-8dBm, (CENELEC standard),more than 47 k-ohms, unbalanced

-6dBm, (CENELEC standard), less than 1k-ohms, unbalanced(100k-ohms,
load)
100Hz to 8,000Hz
More than 38dB
Less than 3% (SP)

TUNER

Tuning system
RF Output

Voltage synthesized tuner Programmable V/S 99CH (Hyper band)
UHF channel 21~69 (52)

TIMER

Memory programmable
Back up time
Clock exactness

99 CH
Less than 1 Hour
In accordance with the exactness of power supply frequency (50Hz)

ACCESSORIES

Provided Accessories Remote control unit, RF Cable, Battery

SYSTEM

SECAM-L

PAL, SECAM-B/G, PAL-I/I

PAL, SECAM-B/G, D/K, HYPER BAND

PAL-I

CHANNEL

VHF Ch 2~12

UHF Ch 21~69

CATV Ch X,Y,Z S1~S41

UHF Ch 21~69

Model

EUROPE Asia, South Africa, Australia

Jack Type

SCART Type RCA Jack (Phone Jack)

*

Design and specification can be subjected to change without notice.

9

CIRCUIT INFORMATION

1. INTERCONNECT WIRING DIAGRAM

10

CIRCUIT INFORMATION

2. POWER CIRCUIT DIAGRAM

11

CIRCUIT INFORMATION

POWER MODE
LOC. PIN EE PLAY REC.
IC802 1 2.46 2.46 2.46

2 4.81 4.83 4.82

3 0 0 0.01
IC801 1 5.88 5.89 5.89
/803 2 4.81 4.83 4.83

3 0.25 0.25 0.25

4 3.1 3.1 3.1

POWER MODE
LOC. PIN EE PLAY REC.
Q801 E 0 0 0

B -0.12 -0.11 -0.72
C 323 323 323

Q802 E 0 0 0

B 0.25 0.26 0.17
C 0.12 0.11 0.17

Q821 E 12.58 12.6 12.6

B 13.2 13.2 13.2
C 15.6 15.36 15.4

Q822 E 5.2 5.19 5.2

B 5.89 5.89 5.89
C 5.97 5.97 5.96

Q825 E 0 0 0

B
C 5.89 5.89 5.89

Q826 E 0 0 0

B 0.73 0.73 0.73
C

1. T801 PIN 1 X : 0.1KV DIV
Y : 5uS DIV

2. T801 PIN 3 X : 2V DIV
Y: 2mS DIV

3. T801 PIN4 X: 5V DIV
Y: 5uS DIV

4. IC801 PIN3 X : 0.5V DIV
Y : 5uS DIV

5. IC801 PIN 4 X: 2V DIV
Y : 5uS DIV

6. Q801 base X: 0.5V DIV
Y : 5uS DIV