DAEWOO DV-F24J Service Manual

SPECIFICATIONS

SYSTEM

Video signal	NTSC color
Channel coverage	VHF Channel 1-12
	UHF Channel 13-62
	CATV Channel C13-C35
VHF output signal	Channel 1 or 2 (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 TRANSPORT

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	100V, 50Hz AC only
Power consumption	17W

DIMENSIONS

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

• 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.

d

Primary circuit termimals

d'

Chassis

a

Table 1: Rating for selected areas				Fig. 1
	AC Line Voltage	Region	Insulation	Dielectric	Clearance
			Resistance	Strength	Distance (d), (d')
	100V	Japan	≥ 1 MΩ /500 V DC	1kV 1 minute	≥ 3 mm
	110 to 130V	USA &	– – –	900V 1 minute	≥ 3.2mm
		Canada
	* 110 to 130 V	Europe	≥ 10 MΩ /500 V DC	4 kV 1 minute	≥ 6 mm (d)
	200 to 240 V	Australia			≥ 8 mm (d')
					(a: Power cord)

* 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)					Exposed
						accessible
	Insert load Z between B (earth ground, power cord plug							AC Voltmeter
						part	Z
	prongs) and exposed accesible parts. Use and AC							(high impedance)
	voltmeter to measure across both terminals of load Z.						Earth Ground
	See figure and following table.
							B power cord plug prongs
	Table 2: Leakage current ratings for selected areas						Fig. 2
	AC Line Voltage		Region	Load Z		Leakage Current (i)		Earth Ground
								(B) to:
	100V		Japan			¡ ≤ 1m A rms		Exposed accessible
				1k				parts
	110 to 130 V		USA &	1.5kµF		¡ ≤ 0.5 m A rms		Exposed accessible
					1.5k			parts
						¡ ≤ 0.7 m A peak		Antenna earth
	110 to 130 V		Europe	2k			¡ ≤ 2 m A dc	terminals
	200 to 240 V		Australia			¡ ≤ 0.7 m A peak		Other terminals
				50k			¡ ≤ 2 m A dc

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

TABLE OF CONTENTS

SECTION 1. CONTROLS AND FUNCTIONS..........................................................................................................	2
SECTION 2. ELECTRICAL ADJUSTMENTS
2-1. SERVO CIRCUIT ADJUSTMENT METHOD .....................................................................................................................	3
2-2. VIDEO CIRCUIT ADJUSTMENT METHOD.......................................................................................................................	4
2-3. AUDIO CIRCUIT ADJUSTMENT METHOD....................................................................................................................	10
SECTION 3. TROUBLE SHOOTING FLOW CHART
3-1. POWER CIRCUIT.............................................................................................................................................................	11
3-2. LOGIC CIRCUIT...............................................................................................................................................................	13
3-3. SERVO/SYSCON CIRCUIT .............................................................................................................................................	16
3-4. AUDIO CIRCUIRT ............................................................................................................................................................	21
3-5. VIDEO CIRCUIT ...............................................................................................................................................................	23
SECTION 4. BLOCK DIAGRAM
4-1. Y.C./HEAD AMP/AUDIO/INPUT SELECTOR BLOCK DIAGRAM.................................................................................	27
4-2. SYSCON/LOGIC BLOCK DIAGRAM..............................................................................................................................	28
4-3. PIF/OSD BLOCK DIAGRAM ...........................................................................................................................................	29
SECTION 5. CIRCUIT DIAGRAM
5-1. CONNECTION DIAGRAM ...............................................................................................................................................	30
5-2. POWER CIRCUIT (SMPS) ...............................................................................................................................................	31
5-3. SYSCON CIRCUIT...........................................................................................................................................................	33
5-4. TIMER CIRCUIT ...............................................................................................................................................................	34
5-5. PIF & INPUT SELECTOR CIRCUIT .................................................................................................................................	35
5-6. HEAD-AMP CIRCUIT.......................................................................................................................................................	36
5-7. VIDEO CIRCUIT ...............................................................................................................................................................	37
5-8. AUDIO CIRCUIT...............................................................................................................................................................	38
5-9. OSD CIRCUIT...................................................................................................................................................................	39
5-10. REMOCON CIRCUIT.....................................................................................................................................................	40
SECTION 6. VOLTAGE CHART
6-1. IC VOLTAGE.....................................................................................................................................................................	41
6-2. TR VOLTAGE....................................................................................................................................................................	48
SECTION 7. COMPONENTS LOCATION GUIDE ON PCB (BOTTOM VIEW)
7-1. PCB HEAD-AMP..............................................................................................................................................................	49
7-2. PCB MAIN ........................................................................................................................................................................	50
7-3. PCB LOGIC......................................................................................................................................................................	51
SECTION 8. DISASSEMBLY
8-1. PACKING AS....................................................................................................................................................................	52
8-2. SET TOTAL ASSEMBLY..................................................................................................................................................	53
SECTION 9. ELECTRICAL PARTS LIST
9-1. STANDARD PART NUMBER CODING ..........................................................................................................................	54
9-2. ELECTRICAL PARTS LIST ..............................................................................................................................................	56
APPENDIX
VCR MECHANISM TECHNICAL SERVICE GUIDE...........................................................................................	65

1

FRONT	SECTION	1.	CONTROLS		AN
DV-F24J
				PLAY
POWER	EJECT		REW	FF
				STOP
			REC / OTR
			CH/TRACK
REAR

	ANT.IN
VIDEO AUDIO
IN	RF OUT
OUT
CH.1	CH.2
2

SECTION 2. ELECTRICAL ADJUSTMENT

2-1. SERVO CIRCUIT ADJUSTMENT METHOD

1. PB Phase

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
MAIN PCB						CH2 ¡ 0.5v/div
		T	10	1
		U
			HEAD-AMP
	8	N
		E
	9
		R
3	6
7			DECK
4	5
		2

6.5¡ 0.5H

• 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

3

2-2. VIDEO CIRCUIT ADJUSTMENT METHOD

1. EE LEVEL

Mode	Adjustment Parts	Check Point	Test Equipments	Test Tape	Input Signal
LINE INPUT	#R395	CH1: TJ313	Signal Gen.		Color Bar
& STOP		CH2: TJ395	Oscilloscope		with 100% white

		Location of Adjustment Parts			Observation Waveform
					H-Axis: 10us/div	V-Axis: 0.1v/div
MAIN PCB
		T	10	1
		U
			HEAD-AMP
	8	N
		E
	9
		R
3	6
7			DECK
4	5
		2

• 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

4

2. PLAYBACK VIDEO OUTPUT LEVEL

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	10	1
		U
			HEAD-AMP
	8	N
		E
	9
		R
3	6
7			DECK
4	5
		2

• 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

5

3. COMB PHASE

Mode	Adjustment Parts	Check Point	Test Equipments	Test Tape	Input Signal
LINE INPUT	%R494	CH1: TJ313	Signal Gen.		Multiburst
& STOP		CH2: TJ494	Oscilloscope

		Location of Adjustment Parts			Observation Waveform
					H-Axis: 10us/div	V-Axis: 20mv/div
MAIN PCB
		T	10	1
		U
			HEAD-AMP
	8	N
		E
	9
		R
3	6
7			DECK
4
	5
		2

• 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: Minimum

6

3. SYNC TIP FREQ.

Mode	Adjustment Parts	Check Point	Test Equipments	Test Tape	Input Signal
STOP	&R391	+: TJ391	Freq. Counter		Without signal
		–: GND

	Location of Adjustment Parts					Observation Waveform
					H-Axis:	V-Axis:
MAIN PCB
	T		10	1
	U HEAD-AMP

8N

9E R

3	6
7	DECK
4	5
	2

• 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

7

5. COLOR REC CURRENT

Mode		Adjustment Parts		Check Point	Test Equipments	Test Tape	Input Signal
LINE INPUT			*R491	CH1: TJ313	Signal Gen.		Color Bar
& STOP				CH2: TJ399	Oscilloscope
		Location of Adjustment Parts			Observation Waveform
					H-Axis: 10us/div	V-Axis: 20mv/div
MAIN PCB
		T	10	1
		U
			HEAD-AMP
	8	N
		E
	9
		R
3	6
7			DECK
4
5
		2

• 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

8

6. Y REC CURRENT

Mode	Adjustment Parts	Check Point	Test Equipments	Test Tape	Input Signal
LINE INPUT	(R399	CH1: TJ313	Signal Gen.		Color Bar
& STOP		CH2: TJ399	Oscilloscope

		Location of Adjustment Parts			Observation Waveform
					H-Axis: 10us/div	V-Axis: 50mv/div
MAIN PCB
		T	10	1
		U
			HEAD-AMP
	8	N
		E
	9
		R
3	6
7			DECK
4	5
		2

• 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)

9

2-3. AUDIO CIRCUIT ADJUSTMENT METHOD

1. Audio REC Bias

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	10	1
	U
		HEAD-AMP

8N

9E R

3 6

7

DECK

4

5

2

• 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.

10

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 KΩ resistance)

•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.

A. CHECKING THE PRIMARY CIRCUIT.

NO output Voltage.
YES
Prepare the instrument
connecting the insulating trans.
YES
Check F801 FUSE.
YES
Is voltage applied to D801?	NO
	Check D801, L801 & L802.

YES

Is voltage applied to the both terminals of C807?

YES

Check voltage of Q801 Gate.

YES

Is voltage output from pin 4 of IC801?

YES

Check Q801.

NO	Check R802.

NO	Check R803, 805,
	814 & 806.

NO	Check Q802, 803,
	D802.
	Check IC801.	NO	Change IC801.

YES

Check the Secondary circuit.

11

B. CHECKING THE SECONDARY CIRCUIT.

IS D811 Short?

NO

Check each votage.

YES

Check Trans output of No output stage.

YES

Check the DIODE of

NO output stage.

YES

Check COIL, C of

No output stage.

YES

Check the environmental terminals of IC801.

YES	Change D811 and check
	IC801 and primary circuit.

12

3-2. LOGIC CIRCUIT

A.

Digitron does not operate.

Is+5V supplied to pin 8 of IC701?

YES

Is-24V supplied to pin 11 of IC701?

YES

Are -20 and -16.5V supplied to pin 1 and 35 of G701?

YES

Are CLK signals supplied to pin 1 , 2 and 3 of IC701?

YES

Is 5V at pin 7 of

IC701?

YES

Check X701.

YES

Check IC701

and change.

NO		NO	Check the
	Is+5V supplied to
	CATHOD of D712?		Fuse of F802.

YES

Check the connector and pattern.

NO	Is-28V at D614	NO	Check D814 and
	anode?		primary power circuit.

YES

Change D614.

NO	Check the Trans output
	and D605.

NO

Check IC601.

NO

Change IC702.

NO

Change X701.

13

B.

Digitron is lit but key do

not operate.

	Is each key pulse	NO
			Check key matrix
	applied to pin 2 , 3
			circuit.
	12 and 13 of IC701?
	YES

Check the pin serial of pin 65 , 67 ~ 69 of IC701.

C.

It has not power-failure compensation operation.

	When disconnecting
	the power cord,is 3.6V	NO	Check C629.
	at pin 26 and 81
	of IC601?
	YES
	Do pin 42 and	NO
			Check X602
	43 of IC601
			environmental circuit.
	oscillate?
	YES
	Is +5V applied to	NO
			Check the IC606
	pin 37 of IC601?		RESET circuit.

YES

Check IC601.

14

D.

When change the channel broadcast signal is not received.

YES

Is the external ANT. connected to RF IN of VCR and RF OUT

of TV?

YES

Is the Power of VCR ON and the VCR indicator lit on the digitron?

YES

Does the TV channel correspond to VCR (3 or 4) channel?

YES

Is the output of pin 100 , 98 of IC601 normal?

YES

Check the Video, Audio outputsignal of pin 14 , 18 of

TMI BLOCK.

NO

Check the TMI

BLOCK.

NO

NO

NO

NO

YES

Change and check the connection of CABLE

Power On and select the VCR mode by pressing the TV/VCR key.

Set the TV channel to

VCR (3 or 4) channel.

Check IC601

Is the signal applied	NO	Check the
to pin 14 of IC151?		IC601 4 4 pin.
YES
Check the
Video circuit.

15

3-3. SERVO/SYSCON CIRCUIT

A.

Playback picture is not good.

Noise appears	NO
		Adjust
although adjusting		tracking.
tracking.
YES
Noise shakes up	NO	Noise appears		YES	Check and
and down on the		although change			re-adjust the
screen.		cassette tape.			Path of Deck.
YES
Is CTL pulse applied	NO	CTL HEAD height is		NO	Adjust the HEAD
to pin 73 of IC601?		normal and there is			height and remove
		not dust.			dust.

	YES
Is CTL pulse input			NO
	to pin 71 and 72 of
	IC601?
	YES
The voltage of pin			NO
	91 of IC601 is not
	changed.
	YES
	Check IC601.

YES	Check circuit
	adjacent to IC601.

Check R523, R524

C508, C509.

check R518 and C511.

16

B.

Playback picture is not good.

Noise appears on the screen whole.

YES

Are SW pulse and

HA SW applied to

HEAD-AMP circuit?

YES

Is Enve.waveform supplied to at pin 4 of PT01?

YES

Check VIDEO circuit.

C.

Auto stop during playback.

NO	Check Flow A.

NO	Is SW pulse supplied		NO	Check D.PG input
	from pin 16 of IC601?			and connector.
	YES
NO
	Check pattern.

	Check connector, Head	NO
			Change Head.
	Amp and Head dust.

Is Reel pulse	NO
		Check REEL
applied to pin 5 and
		sensor part.
6 of IC601?
YES
			NO
		Is D.FG applied to		Check connector
		pin 10 of IC601?		and D.FG circuit.

YES

Check IC601.

17