DAEWOO DV-F46, DV-F26N, DV-F48, DV-F28N, DV-F54 Service Manual

...

DAEWOO ELECTRONICS CO., LTD.

Service Manual

MODEL : DV-F46/26N

DV-F48/28N DV-F54/34N DV-F44/24N/X

POWER

EJECT

REC /OTR

CH/TRACK

REW FF

PLAY

STOP

SYSTEM

Video signal NTSC color Channel coverage VHF Channel 2-13

UHF Channel 14-69 CATV Channel A1-A5, A8, A-W, W+1-W+84

VHF output signal Channel 3 or 4 (selectable)

VIDEO

Input: Video line in Phono-type connector

1.0V (p-p) 75 ohms unbalanced, sync. negative

Output: Video line out Phono-type connector

1.0V (p-p) 75 ohms unbalanced, sync.

negative Signal to noise ratio More than 43dB (SP) Horizontal resolution 230 lines

AUDIO

Input: Audio Line in Phono-type connector

more than 47K ohms,

–8 dBm, unbalanced Output: Audio line out Phono-type connector

less than 1K ohms,

–6dBm (more than 47K ohms

load), unbalanced

Frequency response 100 Hz-10KHz (SP) Signal to noise ratio More than 40 dB Audio Distortion Less than 3% (SP)

TAPE TRANSPOR T

Tape width 12.65mm (1/2") Tape speed SP: 33.35 mm/sec

LP: 16.67 mm/sec

EP: 11.12 mm/sec Maximum recording time 480 min, with T-160 tape (EP) FF. REW time Approx 5 min (T-120)

GENERAL

Power requirements 120V, 60Hz AC only Power consumption 17W

DIMENSIONS

Set size (WxHxD) 360x90x312 mm Carton size (WxHxD) 431x175x397 mm Weight (gross) 5.4Kg (11.9 lbs)

SPECIFICATIONS

• 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 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 below.

3. Clearance distance

When replacing primary circuit components, confirm specified clearance distance (d), (d') between soldered terminals, and between terminals and surrounding metalic parts. See table below.

Table 1: Rating for selected areas

* Class II model only.

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

locality.

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 and output terminals, microphone jacks, earphone jacks, etc.)

Measuring Method: (Power ON) Insert load Z between B (earth ground, power cord plug prongs) and exposed accesible parts. Use and AC voltmeter to measure across both terminals of load Z. See figure and following table.

Table 2: Leakage current ratings for selected areas

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

locality.

Fig. 2

AC Line Voltage Region

Insulation Dielectric Clearance

Resistance Strength Distance (d), (d')

100V Japan ≥ 1 MΩ/500 VDC 1kV 1 minute ≥ 3 mm

110 to 130V

USA &

– – –

900V 1 minute ≥ 3.2mm

Canada

* 110 to 130 V Europe ≥ 10 MΩ/500 VDC 4 kV 1 minute ≥6 mm (d)

200 to 240 V Australia ≥ 8 mm (d')

(a: Power cord)

AC Line Voltage Region

Earth Ground

Load Z Leakage Current (i)

(B) to:

100V Japan ¡ ≤ 1m A rms

Exposed accessible

parts

110 to 130 V USA & ¡ ≤ 0.5 m A rms Exposed accessible

parts

¡ ≤ 0.7 m A peak Antenna earth

110 to 130 V Europe ¡ ≤ 2 m A dc terminals 200 to 240 V Australia ¡ ≤ 0.7 m A peak

Other terminals

¡ ≤ 2 m A dc

Fig. 1

1.5k

1.5kµF

50k

Primary circuit termimals

Chassis

Exposed accessible part

Earth Ground power cord plug prongsB

AC Voltmeter (high impedance)

TABLE OF CONTENTS

SECTION 1. CONTROLS AND FUNCTIONS..........................................................................................................2

SECTION 2. ELECTRICAL ADJUSTMENTS

2-1. SERVO CIRCUIT ADJUSTMENT METHOD.....................................................................................................................5

2-2. VIDEO CIRCUIT ADJUSTMENT METHOD.......................................................................................................................6

2-3. AUDIO CIRCUIT ADJUSTMENT METHOD.................................................................................................................... 12

SECTION 3. TROUBLE SHOOTING FLOW CHART

3-1. POWER CIRCUIT.............................................................................................................................................................13

3-2. LOGIC CIRCUIT...............................................................................................................................................................15

3-3. SERVO/SYSCON CIRCUIT.............................................................................................................................................18

3-4. AUDIO CIRCUIRT............................................................................................................................................................23

3-5. VIDEO CIRCUIT ...............................................................................................................................................................25

SECTION 4. BLOCK DIAGRAM

4-1. Y.C./HEAD AMP/AUDIO/INPUT SELECTOR BLOCK DIAGRAM.......................................................................... .......29

4-2. SYSCON/LOGIC BLOCK DIAGRAM................................................................................................ .............................. 30

4-3. PIF/OSD BLOCK DIAGRAM ...........................................................................................................................................31

SECTION 5. CIRCUIT DIAGRAM

5-1. CONNECTION DIAGRAM...............................................................................................................................................32

5-2. POWER CIRCUIT (SMPS)...............................................................................................................................................33

5-3. SYSCON CIRCUIT............................................................................................................ ............................................... 35

5-4. LOGIC CIRCUIT...............................................................................................................................................................36

5-5. LOGIC CIRCUIT (DV-F54/F34N).....................................................................................................................................37

5-6. PIF & INPUT SELECTOR CIRCUIT.................................................................................................................................38

5-7. HEAD-AMP CIRCUIT.......................................................................................................................................................39

5-8. VIDEO CIRCUIT ...............................................................................................................................................................40

5-9. AUDIO CIRCUIT............................................................................................................................................................... 41

5-10. OSD CIRCUIT ................................................................................................................................................................42

SECTION 6. VOLT AGE CHAR T

6-1. IC VOLTAGE.....................................................................................................................................................................43

6-2. TR VOLTAGE....................................................................................................................................................................50

SECTION 7. COMPONENTS LOCA TION GUIDE ON PCB (BOTTOM VIEW)

7-1. PCB HEAD-AMP..............................................................................................................................................................51

7-2. PCB SHUTTLE (DV-F54/F34N).......................................................................................................................................51

7-3. PCB MAIN........................................................................................................................................................................52

7-4. PCB LOGIC......................................................................................................................................................................53

SECTION 8. DISASSEMBLY

8-1. PACKING AS....................................................................................................................................................................55

8-2. SET TOTAL ASSEMBLY..................................................................................................................................................56

8-3. SET TOTAL ASSEMBLY (DV-54/F34N).......................................................................................................................... 57

8-4. FRONT PANEL ASSEMBLY (DV-F54/F34N)........................................................................................ .......................... 58

8-5. SHUTTLE STATION ASSEMBLY (DV-F54/F34N)..........................................................................................................59

SECTION 9. ELECTRICAL P AR TS LIST

9-1. STANDARD PART NUMBER CODING ..........................................................................................................................60

9-2. ELECTRICAL PARTS LIST..............................................................................................................................................62

SECTION 1. CONTROLS AND FUNCTIONS

POWER

EJECT

REC /OTR

CH/TRACK

REW FF

PLAY

STOP

FRONT

DV-F44/24N

DV-F46/26N

POWER

EJECT REC/OTR

CH./TRACKING

PLAY

STOP

REW FF

CH REC

REW FF

STOP PLAYEJECT

POWER

FRONT

DV-F48/28N

DV-F54/34N

POWER

CH CH

EJECT

REC/OTR

PAUSE

STOP

/ STILL

PLAY

VIDEO AUDIO

CH.3 CH.4

RF OUT

ANT.IN

OUT

REAR

2-1. SERVO CIRCUIT ADJUSTMENT METHOD

1. PB Phase

• Adjustment Procedure

1. Set the oscilloscope to the CHOP mode. Connect the oscilloscope to check point and trigger the scope with CH1.

2. Adjust R595 to position the V-SYNC at 6.5±0.5H from the rising edge of sw pulse.

• Adjustment Inspection Standard: 6.5±0.5 H

SECTION 2. ELECTRICAL ADJUSTMENT

Mode Adjustment Parts Check Point Test Equipments Test Tape Input Signal

CH 1: PT01 #

PB ! R595 CH 2: VIDEO Oscilloscope DN-1

OUTPUT JACK

Location of Adjustment Parts Observation Waveform

H-Axis: 50us/div V-Axis: CH 1 ¡ 1.0v/div

CH2 ¡ 0.5v/div

MAIN PCB

T U N E R

HEAD-AMP

DECK

8 9

2-2. VIDEO CIRCUIT ADJUSTMENT METHOD

1. EE LEVER

• Adjustment Procedure

1. Set the TV/LINE to LINE mode.

2. Supply the color bar signal with 100% white to video input jack.

3. Set the VCR to the stop mode.

4. Connect the oscilloscope to check point and trigger the scope with CH2.

5. Adjust R395 to obtain 0.5±0.01 Vp-p between the sync tip and 100% white level.

• Adjustment Inspection Standard: 0.5±0.01 Vp-p

Mode Adjustment Parts Check Point Test Equipments Test Tape Input Signal

LINE INPUT CH1: TJ313 Signal Gen. Color Bar

& STOP

# R395

CH2: TJ395 Oscilloscope with 100% white

Location of Adjustment Parts Observation Waveform

H-Axis: 10us/div V-Axis: 0.1v/div

MAIN PCB

T U

HEAD-AMP

DECK

2. PLAYBACK VIDEO OUTPUT LEVEL

• Adjustment Procedure

1. Playback the color bar test tape (Dn-1).

2. Connect the oscilloscope to check point and trigger the scope with CH1.

3. Adjust R396 to obtain 2.0±0.2 Vp-p between the sync tip and 100% white level.

• Adjustment Inspection Standard: 2.0±0.2 Vp-p

Mode Adjustment Parts Check Point Test Equipments Test Tape Input Signal

CH 1: TJ313

PB $ 396 CH 2: VIDEO Oscilloscope DN-1

OUTPUT JACK

Location of Adjustment Parts Observation Waveform

H-Axis: 50us/div V-Axis: 0.5v/div

MAIN PCB

T U

HEAD-AMP

DECK

3. COMB PHASE

• Adjustment Procedure

1. Set the TV/LINE to LINE mode.

2. Supply the multiburst signal to video input jack.

3. Set the VCR to the stop mode.

4. Connect the oscilloscope to check point and trigger the scope with CH1.

5. Adjust R494 until the 3.58 MHz component of multiburst signal becomes minimum.

• Adjustment Inspection Standard: Minumum

Mode Adjustment Parts Check Point Test Equipments Test Tape Input Signal

LINE INPUT CH1: TJ313 Signal Gen.

& STOP

% R494

CH2: TJ494 Oscilloscope

Multiburst

Location of Adjustment Parts Observation Waveform

H-Axis: 10us/div V-Axis: 20mv/div

MAIN PCB

T U

HEAD-AMP

DECK

3. SYNC TIP FREQ.

• Adjustment Procedure

1. Set the TV/LINE to LINE mode.

2. Set the VCR to the STOP mode.

3. Connect the frequency counter to check point.

4. Adjust R391 to obtain 3.33±0.1 MHz.

• Adjustment Inspection Standard: 3.33±0.1 MHz

Mode Adjustment Parts Check Point Test Equipments Test Tape Input Signal

+: TJ391

STOP & R391

–: GND

Freq. Counter Without signal

Location of Adjustment Parts Observation Waveform

H-Axis: V-Axis:

MAIN PCB

T U

HEAD-AMP

DECK

5. COLOR REC CURRENT

• Adjustment Procedure

1. Set the TV/LINE to LINE mode.

2. Supply the color bar signal to video input jack.

3. Set the VCR to the stop mode.

4. Connect the oscilloscope to check point and trigger the scope with CH1.

5. Adjust R399 until Y recording current becomes minimum.

6. Adjust R491 to obtain 80±5 mV.

• Adjustment Inspection Standard: 80±5 mV

Mode Adjustment Parts Check Point Test Equipments Test Tape Input Signal

LINE INPUT CH1: TJ313 Signal Gen.

& STOP

* R491

CH2: TJ399 Oscilloscope

Color Bar

Location of Adjustment Parts Observation Waveform

H-Axis: 10us/div V-Axis: 20mv/div

MAIN PCB

T U

HEAD-AMP

DECK

6. Y REC CURRENT

• Adjustment Procedure

1. Set the TV/LINE to LINE mode.

2. Supply the color bar signal to video input jack.

3. Set the VCR to the stop mode.

4. Connect the oscilloscope to check point and trigger the scope with CH1.

5. Adjust R399 to obtain 300±10 mV (at the position of SYNC)

• Adjustment Inspection Standard: 300±10 mV (at the position of SYNC)

Mode Adjustment Parts Check Point Test Equipments Test Tape Input Signal

LINE INPUT CH1: TJ313 Signal Gen.

& STOP

( R399

CH2: TJ399 Oscilloscope

Color Bar

Location of Adjustment Parts Observation Waveform

H-Axis: 10us/div V-Axis: 50mv/div

MAIN PCB

T U

HEAD-AMP

DECK

2-3. AUDIO CIRCUIT ADJUSTMENT METHOD

1. Audio REC Bias

• Adjustment Procedure

1. Set the TV/LINE to LINE mode.

2. Connect the audio level meter to both TP201 and TP202.

3. After inserting a blank tape, record in SP mode.

4. Adjust R292 to obtain 3.0±0.1mVrms.

• Adjustment Inspection Standard:

In confirmation of recording playback frequency characteristics, compared with 1KHz Recording-playback output level, 10KHz Recording-playback output level is higher than the standard, increase the record bias and if lower, decrease it.

Mode Adjustment Parts Check Point Test Equipments Test Tape Input Signal

+: TP1

REC ) R292 –: TP2 Audio level meter Blank tape Without signal

(A/C HEAD PCB)

Location of Adjustment Parts Observation Waveform

H-Axis: V-Axis:

MAIN PCB

T U

HEAD-AMP

DECK

SECTION 3. TROUBLE SHOOTING FLOW CHART

3-1. POWER CIRCUIT

• When change the parts which are out of order, first, remove the power plug from the socket and then discharge the voltage across between both terminals of C807. (Use an external scores of KΩresistance)

• When check the primary circuit by using the oscilloscopes insulate the oscilloscope surely (Use the isulating transformer) and must connect GND into the primary GND (But there is no connection when check the secondary circuit).

• When change IC801, check FUSE and Cement resistance surely.

Prepare the instrument

connecting the insulating trans.

Is F801 fuse opened?

Have the noise been heard

in the trans?

Is the value of registor

R806 (0.68 ) normal?

Check L801, D801 and C806.

YES

NO output Voltage.

A. CHECKING THE PRIMARY CIRCUIT.

Change F801.

YES

Change.

YES

Is voltage applied to D801?

Is the power trans normal?

Are D809, Q801, Q802, R805

and R806 normal?

Is the secondary voltage

EVER 5.8V and -28V normal?

Are R810, D808 and

F802 normal?

Are R804 and D802 normal?

Is IC801 normal?

Change.

Change

Is each voltage of secondary

circuit normal?

Check the trans output of

NO output stage.

Check the diode of

NO output stage.

Check COIL, C of

NO output stage.

YES

3-2. LOGIC CIRCUIT

Digitron does

not operate.

Is+5V supplied to

pin of IC701?

Is-24V supplied to

pin of IC701?

Are -20 and -16.5V

supplied to pin and

of G701?

Are CLK signals

supplied to pin ,

and of IC701?

1 2

Is 5V at pin of

IC701?

Check X701.

Check IC701

and change.

Check the

Fuse of F802.

Is+5V supplied to

CATHOD of D712?

Is-28V at D614

anode?

Check D814 and

primary power circuit.

Change D614.

Check the Trans output

and D605.

Check IC601.

Change IC702.

Change X701.

YES

Check the connector

and pattern.

Digitron is lit but

key do

not operate.

Is each key pulse

applied to pin ,

and of IC701?

2 3

12 13

Check key matrix

circuit.

Check the pin serial of pin , ~ of IC701.

65 67 69

It has not power-failure

compensation

operation.

When disconnecting

the power cord,is 3.6V

at pin and

of IC601?

26 81

Do pin and

of IC601

oscillate?

Is +5V applied to

pin of IC601?

Check IC601.

Check C629.

Check X602

environmental circuit.

YES

Check the IC606

RESET circuit.

When change the

channel broadcast

signal is not received.

Is the external ANT.

connected to RF IN of

VCR and RF OUT

of TV?

Is the Power of VCR

ON and the VCR

indicator lit on the

digitron?

Does the TV channel

correspond to VCR

(3 or 4) channel?

Change and check the

connection of CABLE

Power On and select

the VCR mode by

pressing the

TV/VCR key.

YES

Set the TV channel to

VCR (3 or 4) channel.

Check the Video,

Audio outputsignal of

pin , of

TMI BLOCK.

Check the TMI

BLOCK.

Check IC601

Check the

Video circuit.

Check the

IC601 pin.

Is the output of pin

, of IC601 normal?

100 98

YES

14 18

Is the signal applied

to pin of IC151?

YES

The voltage of pin

of IC601 is not

changed.

Is CTL pulse input

to pin and of

IC601?

71 72

Check and

re-adjust the

Path of Deck.

Check circuit

adjacent to IC601.

Check R523, R524

C508, C509.

check R518

and C511.

Check IC601.

YES

YESNO

NO NO

Playback picture

is not good.

Noise appears

although adjusting

tracking.

Is CTL pulse applied

to pin of IC601?

Noise shakes up

and down on the

screen.

Adjust

tracking.

CTL HEAD height is

normal and there is

not dust.

Adjust the HEAD

height and remove

dust.

Noise appears

although change

cassette tape.

3-3. SERVO/SYSCON CIRCUIT

+ 47 hidden pages