Daewoo DV-6T712D, SD-3100K, DV-6T722D, SD-7100K Service Manual

S/M No. : VTB712DET0

Service Manual

MODEL: DV6T712D / DV6T112D DV6T712P / DV6T112P DV6T712S / DV6T112S DV6T722D

DV6T722P

DV6T722S

DVD

VCR

	MENU	DISPLAY
TITLE/PBC
OPEN/CLOSE	PR	OUTPUT

RETURN/OK

SETUP

ENTER

CLEAR/3D

REPEAT	ZOOM PR	AUDIO	SUBTITLE
PREV	PLAY/PAUSE		NEXT
PROGRAM			SEARCH
	CLK/CNT	MARK
REC	SPEED/ANGLE	TV/VCR
	TRACKING
			SYSTEM

Caution

:In this Manual, some parts can be changed for improving, their performance without notice in the parts list. So, if you need the latest parts information,please refer to PPL(Parts Price List) in Service Information Center (http://svc.dwe.co.kr).

DAEWOO ELECTRONICS CO., LTD.

http : //svc.dwe.co.kr

Nov. 2002

CONTENTS

SPECIFICATIONS ...........................................................................................................	2
ADVANTAGES OF THIS PRODUCT ...............................................................................	3
TROUBLE SHOOTING ................................................................................................................	5
WAVEFORMS............................................................................................................................	25
CIRCUIT DIAGRAM..................................................................................................................	28
PCB CIRCUIT BOARD ..............................................................................................................	34
INSTRUMENT DISASSEMBLY...............................................................................................	37
ELECTRICAL PARTSLIST.........................................................................................................	45

1

SPECIFICATIONS

Power			230V~, 50Hz
Consumed electricity			Hi-Fi : 24W, Mono : 23W
Weight			5.7kg
Dimension (W x H x D)			430mmx91mmx355.5mm
Operative temperature			+5°C~40°C
Installation condition			Horizontal / Relative humidity under 80%
Signal type			PAL/SECAM/MESECAM COLOR
Antenna Input/output			U/V-mixed: 75Ω unbalanced
VIDEO input			1.0Vp-p (unbalanced, RCA JACK)
AUDIO input			-8.8dBm, RCA JACK
VIDEO output (common use of DVD and VCR)			VIDEO output terminal, 1.0 Vp-p unbalanced, RCA JACK, SCART JACK
VIDEO output (DVD only)			RGB output (75Ω In load R: 0.7Vp-p, G:0.7Vp-p, B:0.7Vp-p)
AUDIO output (common use of DVD and VCR)			Audio output terminal (2 kinds): -8.8dBm(VCR), 2Vrms(DVD), RCA JACK
AUDIO output (DVD only)			Analogue AUDIO output : 2.0Vrms
			Digital audio output (OPTICAL, COAXIAL)
Playable tape			Very high dense tapes with VHS marks
Playable disc			DVD, VIDEO-CD, CD (12mm), CD (8mm), MP3, CD-R, CD-RW
Tape speed			SP: 23.39mm/s, LP: 11.70mm/s
Playtime			SP: 3hrs, LP: 6hrs (use of E180tape)
Clock display			24 hrs
Time Recording			8 programs a year
Persistence in power failure			1min
VIDEO S/N (VCR)			Over 43dB(Standard recording)
Resolution		VCR	Over 240 lines (Standard recording)
		DVD	Over 500 lines (Playback DVD)
AUDIO (VCR)			Over 65dB(Hi-Fi), Over 40dB(Mono)
AUDIO (DVD)			90dB
AUDIO dynamic range			90dB

DVD Audio output standards

	Output		Disc type
		DVD	VIDEO-CD	CD
	Analogue Audio output	48/96KHz sampling	44.1KHz sampling	44.1KHz sampling
	Digital Audio output	48KHz sampling	44.1KHz sampling	44.1KHz sampling
	Optical digital audio output	48KHz sampling	44.1KHz sampling	44.1KHz sampling

2

ADVANTAGES OF THIS PRODUCT

•DVD, VCD, CD, CD-R(MP3), CD-RW, VHS

•DVD one-touch record function

•Watching DVD for recording broadcast

•Integrated remote control (VCR, DVD)

•VISS function

•Multiplex sound playback/record (Hi-Fi Model)

•High Sound Quality of 6 head Hi-Fi (Hi-Fi Model)

•Simple record function

•MP3 file playback function (CD-R disc having records of MP3 files)

•GUI (Graphical User Interface) through OSD (On Screen Display)

By using the [DISPLAY] button on the remote control, information on the DVD/VCD/CD player and disc, can

be displayed on the TV screen.

•Screensaver function (DVD)

•3D sound (3D sound effect using 2 speakers)

•High bit / High sampling with 27MHz / 10bit video encoder

•High bit / High sampling with 96MHz / 24bit Audio D/A Converter

•Coaxial, Optical digital Audio output (PCM, Dolby Digital, dts)

You can enjoy high-level digital audio by connecting with amp embedded with Dolby Digital / dts decoder.

•Built-in Dolby Digital decoder (DVD)

•Analog audio 2-channels output for DOWNMIX (x1)

•Composite video output (x1)

3

ADVANTAGES OF THIS PRODUCT

•Slow Forward / Reverse playback (DVD)

•Fast Forward / Reverse playback

•Search of title, chapter, and time in DVD disc, and search of time and track time in VCD and CD

•Various TV aspect (DVD)

4:3 for Pan and Scan, 4:3 for Letter Box, and 16:9 for Wide

•Repeat playback (title, chapter and part for DVD / track, disc and part for VCD/CD)

•Selective Play (DVD/VCD/CD)

You can select and play the desired title / chapter of DVD and track of Video CD/CD in STOP mode.

• 7 languages OSD (On Screen Display) function (DVD)

You can select and display OSD in 7 languages. (E/F/S/G/I/D/P)

• Parental Lock function (DVD)

This function can prevent playback of software that may be unsuitable for children.

• Multi Audio function (DVD)

The audio soundtrack can be heard in up to 12 languages. In the case of SVCD or VCD, it depends on the disc. (The number of audio languages depends on the software.)

• Multi Subtitle function (DVD)

The subtitle can be seem in up to 12 languages. In the case of SVCD or VCD, it depends on the disc. (The number of audio languages depends on the software.)

• Multi Angle function (DVD)

This function allows you to choose the viewing angle of scenes which were shot from a number of different angles. (The number of angles depends on the software.)

• Screen zoom function (DVD/VCD)

4

TROUBLESHOOTING

1.POWER CIRCUIT

CAUTION

You must use insulated trance during the first part test of POWER circuit.

No power

POWER cord is ok?

YES

Is 400~200V voltage obtained at C805 +?

YES

Output voltage of 2nd parts is normal?

YES

Check

rectifier diode of 2nd parts ; D821, D822, D823, D825, D826, D827

YES

Switching

pulse of IC801 pin#4 or pin#5 is normal?

NO

Exchange POWER CORD

NO

Check

F801,L801,L802,D801.

NO

Check IC601,IC701.

NO		Exchange rectifier diode of
		2nd parts ; D821, D822, D823,
		D825, D826, D827.

NO

Check IC801.

YES

OK

5

TROUBLESHOOTING

2.SYSTEM CIRCUIT

A.LED DISPLAY

No LED display.

Is 5V obtained at IC701 pin #9, 25?

YES

Oscillation at IC701 pin #1?

YES

Specific GRID/SEG doesn’t function.

YES

GRID output at PORT of IC701?

YES

SEG output at PORT of IC701?

NO

Check R705, L601.

NO

Exchange IC701.

NO		Check IC 701 pin #22~24, 27,
		28, 30, 31.

NO

Check IC 701 pin #10~12, 14~21.

Exchange IC601.

6

TROUBLESHOOTING

B. No power compensation.

No power compensation.

YES
				NO
Voltage of power fail (IC601								Check R644.
pin#3) at micom is 0.7V over?
YES
More than 3.2V is maintained				NO
for 1 minutes at IC601 pin#37								Check RESET circuit.
during Power Cord Open.

Exchange IC601.

7

TROUBLESHOOTING

C-1. Bad playback quality (1)

Noise appears on the playback screen.

Is noise diminished by tracking adjustment.

YES

Noise band is trembled up and down?

YES

NO

Re-adjust PATH.

NO		Noise appears on the screen		YES
						Re-adjust PATH.
		even though changing tape.

Is there CTL pulse at IC601

NO

Is the height of CTL HEAD normal?

NO

Re-adjust the height of AC

pin#97?

No dust?

HEAD. Remove the dust.

YES

Check IC601.

Is there problem in CTL Input

YES

Check C651, C652, R651~R653

circuit and amplifier.

IC601 pin #91, 92, 98.

8

TROUBLESHOOTING

C-2. Bad playback quality (2)

Noise appears on the Full playback screen.

YES

Recheck step C-1 (Bad playback quallty (1)).

Are SW pulse and HA SW normal?

YES

ENVE Wave at PT01 pin #4?

	NO		Are there SW, HA SW pulse at			NO
			IC601 pin #16, 18?						Check IC601.
				YES
	NO								Check PCB Pattern.
			Check HEAD AMP connector and
			HEAD.

YES

Check VIDEO circuit.

D. No broadcasting signal received

No broadcasting signal received

YES

Is the output at IC601 pin# 71(CLK), 72 (DATA) normal?

YES

Is SIF,Video output at TMI(RF101) pin#18,20 normal?

YES

Is Video Signal input at IC601 pin#50?

YES

Is there Video output at IC601 pin#52?

NO

Check IC 601.

NO

Check TMI (RF101) Block.

NO

Check IC301.

NO

Check IC601.

YES

Check Video Buffer Q156, Q157.

9

TROUBLESHOOTING

E. No CASSETTE Loading

Cassette tape isn’t inserted.

Is 5V voltage obtained at								NO
Loading parts IC601 pin#82?
YES								NO
Is 13V voltage obtained at
Capstan Motor pin#8?
YES
Is 12V voltage obtained at Each								NO
parts of Loading Motor?
YES
Replace Loading Motor.

Check at ON/OFF 12.

Check (D822, Q851).

Check D851 and POWER circuit.

Connect Capstan and Loading Motor.

Check connector and Capstan Motor.

F. AUTO STOP in Playback mode

VCR stops automatically in playback mode.

Is there REEL Pulse at IC601		NO
pin#79, 80?

YES

Check S603, S604 REEL Sensor.

Is D.PG/FG pulse at IC601 pin#90 normal ?

YES

Is C. FG pulse at IC601 pin#87 normal ?

YES

Check and replace IC601.

NO

Check R656,C659 and P603 pin#11

NO		Check C.FG(R660, C660)
		and P603 pin#1.

10

TROUBLESHOOTING

G. DRUM Motor stops

DRUM Motor stops.

Is 13V voltage obtained at P603 pin#8?

YES

Is DRUM PWM fit to IC 601 pin#76?

YES

	NO			Check ON/OFF 13V
				(D851, Q856).
	NO			Check DRUM PG/FG
				(IC 601 #90).

Is 1.2V voltage obtained at		NO		Check R657, R658,C661,C668.
P603 pin#12?

YES

Check Capstan Motor and

DRUM Motor.

H. CAPSTAN doesn’t rotate

CAPSTAN doesn’t rotate.

Is 14V voltage obtained at P603							NO			Check 14V.
pin#2?										(Q856,Q857,Q852)
YES
Is Capstan PWM fit to IC 601							NO			Check Capstan FG
pin#77?										(IC 601 #87).
YES
Is 3.2V voltage obtained at							NO			Check R665, R664, R663,
P603 pin#5?										R666, C665.
YES							NO
Is 2~3V voltage obtained at										Check R661, R667, C664.
P603 pin#9?
Check P603 Connector and
Capstan Motor.

11

TROUBLESHOOTING

3. VIDEO circuit

A.EE screen doesn’t appear

EEscreen doesn’t appear.

	YES					NO
	Is Video signal input at IC301
	pin#48,50,52,54?
	YES					NO
	Is 5V obtained at IC301 pin#24,
	42, 55, 72, 91?
	YES					NO
	Is signal input at IC302
	pin#1,5,12,13,14,15?
	YES					NO
	Is signal output at IC302 pin#3?

YES

	Is signal input at IC601 pin#50?							NO
	YES							NO
	Is signal output at IC601 pin# 52?
	YES							NO
	Is signal input at IC301 pin# 56?
	YES							NO
	Is signal output at IC301
	pin# 62, 63?

YES

NO

Check RF Output.

Check LINE JACK and IF circuit. Check DVD circuit.

Check POWER 5V.

Check LINE JACK and IF circuit. Check DVD circuit.

Check IC302 pin#16VCC. Check IC302 pin#9,10,11(control DC)

Check PCB Pattern.

Check IC604 pin#3(C sync).

Check PCB Pattern.

Check VCC of IC301 and

pin #68,69.

Check LINE.

12

TROUBLESHOOTING

B. Playback picture doesn’t appear

Playback picture doesn’t appear.

YES				NO
Is Envelope output at IC301
pin#79?

YES

Is Y signal output at IC301		NO
pin#46?

YES

Is Y signal input at IC301 pin#43?

YES

NO

Check

Pattern.

Is Video signal output at IC301

NO

pin#65?

YES

Is Video signal output at IC302

NO

pin#3?

YES

NO

Is Video signal input at IC601

pin#50?

YES

Check IC604 PIN#3(C sync)

Is 5V obtained at IC301

NO

pin#91?

YES

Is SW Pulse input at IC301

NO

pin#70?

YES

Is 5V obtained at IC301

NO

pin#24,42,55,64?

YES

Check and Replace IC301.

Does X301(4.43MHz) oscillate?

YES

NO

Replace X301.

Check IC301 pin# 62.68,69,70.

NO

NO

Check PCB Pattern.

Check PCB pattern

Check POWER 5V.

Check IC601 pin#18.

Check and Replace HEAD.

Check POWER 5V.

Check Pattern.

IC302 pin#9,10,11(control DC), 16(Vcc)

13

TROUBLESHOOTING

C. No recording

No recording.

Check EE MODE.

YES

Is FM signal output at IC301 pin#78?

YES

Is 5V obtained at IC301 pin#91?

YES

Is IC301 pin#80 REC(H) HIGH?

YES

Is VIDEO SW Pulse input at IC301 pin#70?

YES

Is REC signal input at IC301 pin#94, 95, 89, 90?

EP MODE: 89, 90 Pin

SP MODE: 94,95Pin

Check HEAD and Connector.

	NO			Is signal input at IC301 pin#
				48, 50, 52, 54?
	NO
				Check POWER circuit.

NO

Check IC601 pin#22.

NO	Check IC601 pin#18.

NO

Replace IC301.

14

TROUBLESHOOTING

D. No OSD(On Screen Display) appears

No OSD appears.

YES

Is 5V obtained at IC601 pin# 53, 98, 99?

YES

Is Video signal output at IC601 pin#52?

NO

Check POWER circuit.

NO		Is Video signal input at IC601		NO		Check IC 301.
		pin#50?

Check IC 601.		Check IC 601.

15

TROUBLESHOOTING

4.AUDIO (Hi-Fi MODEL)

A.No sound in E-E mode A. a.RF E-E

No sound in RF E-E mode

Is there Audio at IC252 pin#4,11?

YES

Is RF Audio signal output at IC252 pin#3,13?

YES

C at Q904 is L or H?

L

Check Output JACK.

NO

Check IC121, RF101 block.

NO

H			IC601 pin#27		H			Check IC601.
			A.Mute is L or
			H?
				L
			Check Q904, Q905,
			R937,R938,R939

Is 12V obtained at IC252 pin#16?

YES

IC601 pin#31 is H, pin#21 is H?

YES

Is about 8V obtained at IC252 pin#9?

Is about 8V obtained at IC252 pin #10?

YES

NO

Check POWER circuit.

NO

Check IC601.

NO	Check R646, R647.

Replace IC252.

16

TROUBLESHOOTING

A. b. AV1 E-E

No sound in AV1 E-E mode.

YES

NO

Is there Audio IC252 pin#2,15?

Check Input JACK.

YES

NO

NO

Is RF Audio signal output at

Is 12V obtained at IC252

Check POWER circuit.

IC252 pin#3,13?

pin 16?

YES

IC601 pin#31 is H,

NO

Check IC601.

pin#21is L?

YES

YES

C at Q904 is L or H?

H

IC601 pin#27

H

Check

Is about 8V obtained at

NO

Check R646, R647, R911,

A.Mute is L or

IC601.

IC252 pin#9?

R913.

H?

Is about 3.5V obtained

L

L

at IC252 pin #10?

Check Output JACK.

Check

YES

Q904,Q905,R9

37,R938,R939

Replace IC252.

17