Sanyo C28WN1 Schematic

Part No. SKSM0216 F2HT/HV SEPTEMBER 1997

Colour Television Service Manual

Model C28W1(Europe)

C28WN1(Europe)

Service Ref. No. C28W1-00 Service Ref. No. C28WN1-00

Give complete "SERVICE REF. NO." for parts order or servicing, it is shown on the rating sheet on the cabinet back of the TV set.

Note This TV receiver will not work properly in foreign countries where the television transmission system and power source differ from the design specifications. Refer to the specifications for the design specifications

PRODUCT CODE 1113 29315 (C28W1) 1113 29316 (C28WN1)

ORIGINAL VERSION Chassis No. WB2-B

Contents

Safety notice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

Pin configuration of system control, CPU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Chassis block diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-6

IC block diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-12

Adjustment locations on the board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13-15

Service control adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

Circuit alignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Adjustments in the service mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18-20

Special functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

Cabinet parts list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

Electrical parts list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23-37

-2-

F2HT

SAFETY PRECAUTION

X-RADIATION PRECAUTION

The primary source of X-RADIATION in the television receiver is the picture tube. The picture tube is specially constructed to limit X-RADIATION emissions. For continued X-RADIATION protection, the replacement tube must be the same type as the original including suffix letter. Excessive high voltage may produce potentially hazardous X-RADIATION. To avoid such hazards, the high voltage must be maintained within specified limit. Refer to this service manual, high voltage adjustment for specific high voltage limit. If high voltage exceeds specified limits, take necessary corrective action. Carefully follow the instructions for +B1 volt power supply adjustment, and high voltage adjustment to maintain the high voltage within the specified limits.

PRODUCT SAFETY NOTICE

Product safety should be considered when a component replacement is made in any area of a receiver. Components indicated by mark //!\

in the parts list and the schematic diagram designate components in which safety can be of special significance. It is particularly recommended that only parts designated on the parts list in this manual be used for component replacement designated by mark /!\ . No deviations from resistance wattage or voltage ratings may be made for replacement items designated by mark /!\ .

1: An isolation transformer should be connected in the

power line between the receiver and the AC line when a service is performed on the primary of the converter transformer of the set.

2: Comply with all caution and safety-related notes

provided on the cabinet back, inside the cabinet, on the chassis or the picture tube.

3: When replacing a chassis in the cabinet, always be

certain that all the protective devices are installed properly, such as, control knobs, adjustment covers or shields, barriers, isolation resistor-capacitor networks etc.Before returning any television to the customer, the service technician must be sure that it is completely safe to operate without danger of electrical shock.

Specifications (C28W1/C28WN1)

Power source AC 220~240V 50Hz Television system System B/G) Colour system PAL Receiving channel VHF E2~E12

UHF 21~69 CATV S1~S41, X,Y,Z, Z+1, Z+2

Common Specifications

Aerial input impedance 75ohm AV terminal

21 Pin socket AV1 CENELEC standard<RGB/,S-in>

AV2 CENELEC standard Front AV terminal AV3 RCA type,Video,Audio-L/R input Sound output Main 10 watts X2

Picture tube 70cm diagonal, 106 degree (Visible picture diagonal) 66cm Dimensions (WxHxD) 739 x 494 x 485 mm Weight 38.5 Kg

SPECIFICATIONS

SAFETY NOTICE

-3-

F2HT

PIN CONFIGURATION OF SYSTEM CONTROL, CPU

SYSTEM CONTROL

IC101 TDA8361

IDENT 4

COLOUR 26

BRIGHT 17

CONTRAST 25

SHARPNESS 14

AFT 44

D/A

CONVERTER

CIRCUITS

I DENT

CHROMA ID

KEY IN

RC SIGNAL

COLOUR

BRIGHTNESS

CONTRAST

SHARPNESS

SCLK

DATA

I2C BUS SW.

IC801 M37207MB-

1

2

4

5

8

9

10

11

13

14

15

60

63

62

61

60

59

57

56

55

53

52

Vcc +5V

H-SYNC

V-SYNC

OSD RED

OSD GREEN

OSD BLUE

OSD BLANKING

POWER ON/OFF

LED DRIVE

AV1 SW

AV2 SW

FBP

SANDCASTLE PLS

TO Q203, Q204, Q205

TO IC201PIN21

TO IC1001 PINS 6, 12

TO Y/C SEPARATION BOARD

TO SUB VIDEO BOARD

SYNC ID

PAL/NTSC

THRESH HOLD

SQ

CLK

SI

AFT

I2C SCL

I2C SDA

OSC

16

17

19

20

21

22

23

25

26

30

31

46

45

44

43

42

41

36

34

33

SOUND MUTE

LINE MUTE

SC1 FUNCTION

FROM

SC2 FUNCTION

POWER FAILURE DET.

IGNORE

TITLE IN

PITTARI

NORMAL

SCART1, 2

TO DEFLECTION BOARD

-4-

F2HT

CHASSIS BLOCK DIAGRAMS

CRT

CRT BOARD

Q2761

Q2772

Q2782

VIDEO-OUT

R/G/B

TELETEXT BOARD

R/G/B/BLK-OUT

VIDEO-IN

Q203

Q204

Q205

201918

45

46

R/G/B BUFFER

BLK-IN

21

R/G/B/BLK FOR OSD FROM CPU

R/G/B-OUT

IC101

TDA8361

X101

SAW

Q101

1

A101

TUNER PACK

Q135

Q132

Q134

EQUALISER

SIF TRAP

Q122

VIDEO-IN(INTERNAL)

VIDEO-OUT

7

13

Y-IN

15

303128

R-Y/B-Y-OUT

161411

IC270

TDA4661

<1H DELAY>

C-IN

16

12

R/G/B-IN

222324

29

R-Y/B-Y-IN

AV1

AV2

TV-IN

MONITOR-OUT

35

IC1001

TA8747N

R/G/B/BLK-IN

C-OUT

28

33

1

VIDEO-IN

Y-OUT

31

6

12

25

7

VIDEO-IN

2313

VIDEO-IN

BACK BOARD

BLOCK DIAGRAM <VIDEO SIGNAL PROCESSING>

FROM

CPU

AV1

AV2

AV3

-5-

F2HT

FRONT

L SPEAKER

FRONT

R SPEAKER

HEADPHONES

12

IC001

AUDIO OUTPUT

IC3451

2

FOR FRONT

L

NICAM

IC3401

DUAL SOUND

7

4

R

8 7

16

L

R

AMP

IC3451

IC3501

Monitor-out

3D SURROUND

L

R

8

15

7

16

L

14

7

29

9

NICAM

BOARDD

R

13

8

IC1001

AV SELECTOR

TV-out

L

14

3

L

13 23

L

27

2

36

TV-L

AV1-L

AV2-L

8

R

8 5

R

11

1

R

26

14

TV-R

AV3-L

34

AV1-R

4

10

AV3-R

AV2-R

16

BACK BOARD

AF2

AF1

8

7

MAIN

12 1

1

15

SUB

16

SIF BOARD

IC3811

A2 STEREO

SIF

IC3801

Q101

A101

TUNER PACK

BLOCK DIAGRAM < AUDIO SIGNAL PROCESSING>

SIF

MONO.

1

6

IC101

IF/VIDEO/CHROMA

AV1

AV2

AV3

-6-

F2HT

BLOCK DIAGRAM <H&V DEFLECTION>

IC101 VIDEO/CHROMA/DEFLECTION <TDA8361>

H-DRIVE

37

Q402

ABL

MODE SW FROM CPU

NORMAL/ PITTARI

IC531 V-DRIVE <TA8859AP>

T401 H-DRIVE

Q403 H-OUTPUT

PCC Q461 Q462

IC521 PCC <BA4558N>

7

8

IC423

1

3 4

C421 C422

C465

L461

C424

Q421 S-C SW

C425 C426 C427

T402 FLYBACK

HIGH VOLTAGE

DELECTION YOKE

HORIZ.

VERT.

C512

42

39

VR371 H-CENTRE

V-DRIVE

SCL

SDA

I2C BUS

10

1

13

9

PCC

2

V-TRIGGER

8

6

V-FEEDBACK

IC501 V-OUTPUT <LA7833>

4

R512

2

-7-

F2HT

IC BLOCK DIAGRAMS

TDA8361 <IF/VIDEO/CHROMA/DEF.>

TO

TDA4661

DET

BYO

31

33

30

BYI

28

FROM

TDA4661

RYI

29

RO

BI

GI

RI

23

24

22

BO

GO

20

18

19

XTAL2

XTAL1

FBI/SCO

PH2LF

PH1LF

V RAMP

HUE

XTAL OUT

H OUT

V OUT

H OSC

VFB

27

CLAMP

PHASE

HUE

CONTROL

3235

3437

XTAL

OSCILLATOR

38

39

PHASE 2

36

40

PHASE 1

42

41434448

VERTICAL

OUTPUT

DETECOR

SYSTEM

MANAGER

TUNING

LINE

OSCILLATOR

VERTICAL

DIVIDER

DEMODULATOR

COLOUR

KILLERS

COINCIDENCE

DETECTOR

H AND V

SEPARA TION

POWER

RESET

CLAMPS

SET

MATRIX

ACC

AMPLIFIER

NOISE

DETECTOR

TDA8361

SWITCH

LUMINANCE

MATRIX

CHROMINANCE

BANDPASS

CHROMINANCE

SWITCH

TRAP AND

BYPASS

17

OUTPUT

STAGES

21

26

25

PWL

Y DELAY

PEAKING

13 15 14

LUMINANCE

SWITCH

12 16

TUNING

BRI

RGBIN

CON

PEAK IN

CVBS

EXT

CVBS

INT

CHROMA

COLOUR

DEC

FT

DEC

AGC

AFCOUT

AGC OUT

AU OUT

IDENT

4750

4

AGC

IF

45

IF IN1

AMPLIFIER

49

46

IF IN2

TUNE ADJ

AFC AND

SAMPLE

AND HOLD

DEMODULATOR

3

2

FM DEM1

7

IFVO

FM DEM2

VIDEO

AMPLIFIER

VIDEO

IDENTIFICATION

1

AUDEM

6

PREAMPLIFER

MUTE

SWITCH

VOLUME

51

DECDEM

EXTAU

PLL

LIMITER

5

SOIF

TEST

SUPPLY

8

DEC

DIG

10 52

DEC BG

Vp

11 9

GND2 GND3

-8-

F2HT

TDA4661 <1H DELAY LINE>

TA8859AP <DEFLECTION CORRECTION>

LA7833 <VERTICAL OUTPUT>

16

±(R-Y)

colour-difference input signals

±(B-Y)

Vp1

sandcstle pulse input

SIGNAL CLAMPING

14

9

analogue supply

5

SANDCASTLE DETECTOR

SIGNAL CLAMPING

10 GND1

pre-amplifiers

FREQUENCY PHASE DETECTOR

LINE MEMORY

DIVIDER BY 192

LP

digital supply

SAMPLEANDHOLD

3MHz shifting clock

6 MHz CCO

1

Vp2

LP

addition stages

LP

TDA4661

DIVIDER BY 2

GND2

output buffers

3

11

colour-difference output sugnals

12

2 6

n.c.

13

n.c.

15

7 i.c.

4,8

±(R-Y)

±(B-Y)

n.c.

16

AGC

PALABOLA CORR.

1

ETH IN

RAMP

VCC

6

15

∫

2

ETH

14

PULSE SHAPER

CORRECT

3

Vcc

DRIVE

TRIG

IN

13

TRIGGER

LINEARUTY CORRECTION

ETH CORR.

EW

ETH CORR.

F/B

12

11

PULSE INFERFACE

S-C CORR.

TA8859AP

654

GND

3

VERT

F/B

7

PUMP UP

10

7

SCL

9

8

SDA

VERT.

DRIVE

V-DRIVE PLS INPUT

4

VERTICAL DRIVE

15

GND

VERTICAL OUTPUT

THERMAL PROTECTION

2

V-OUTPUT

LA7833

-9-

F2HT

TA8216H/TA8200AH<AUDIO OUTPUT>

TA8747N <AV SELECTOR>

R IN

RE4

Vcc

32

16 10

TA8747N

29

24

GND

MODE OUT

E3

R

RE2

4

MUTE

AUDIO

DECODER

18

22

SW3

MUTE

E1

R

20 34

SW2

RTV

612

SW1

L IN

LE3

LE4

14 8 2

R OUT

LE2

MUTE

2726

L OUT

13

31

E3

E2

71

VIDEO IN

CLAMP

28

E1

TV

21 35

X2

30

MONITOR OUT

C IN

TV

LE1

L

C3

C2

19

36

VIDEO

17

11

X2

33

C OUT

Y IN

Y 3

C1

5

23

15 9

÷2

C IN

Y2

Y1

X2

25

Y IN

E4

3

Y OUT

COMB FILTER

AMP2

12 3456789101112

GND

AUDIO

IN2

AUDIO

IN1

AMP1

RIPPLE

FILTER

OUT1

TA8200AH

GND

VCC

SPEAKER

OUT2

SPEAKER

-10-

F2HT

TDA9821 <DUAL CHANNEL SOUND DEMODULATOR>

TDA2545A <SIF DEMODULATOR>

38.9MHz

9

REF. AMP.

DEMODULATOR

10

LIMITER AMP.

14

5.5MHz (5.742MHz)

IF INPUT

TDA2546A

1st Sound IF & Demodulator

17

18

1

2

AGC

DEMO.

3

LIMITER AMP.

12

External FM demodulator

5.5MHz (5.742MHz)

87

2nd Sound IF & FM Demo.

FM DEMO.

13 11 5

6

4

Cd

OUTPUT

MUTE

INTERCARRIER

5.5MHz (B/G)

5.74MHz (B/G)

TDA9821

1

15

SUPPLY

13 14 12 11

Vp

7-STAGE LIMITTER AMPLIFIER 1

7-STAGE LIMITTER AMPLIFIER 2

REF

VCO

OPTIONAL STEREO CHANNEL SEPARATION ADJUSTMENT

MUTE

VCO1

VCO2

9

10

8

VAF1

VAF2

7

-11-

F2HT

SAA7283ZP <NICAM DECODER>

TDA9840 <STEREO/DUAL SOUND PROCESSOR>

MIXREF

DQPSK

SOFF

SEYE

23

28

29

QUADRATURE MIXERS, BASEBAND FILTERS

AND AGC GAIN STAGE

2430313637

26

COFF

VSSF1

CEYE

VDDF1

PKDET

3222

SINE

AGC

CONTROLLER

COSINE

CARRIER LOOP

PHASE DETECTOR

AND DATA SLICERS

21 20

REMO

VSSF2

VDDF2

REMVE

34 33

IREF

35 39

VRCF

VROF

VCONT

VCLK

27

CARRIER LOOP

QUADRATURE VCO

BIT RATE

CLOCK RECOVERY

48

CLKLPF

DATAOUT

PCLK

TEST

4525

43 40

XTAL

DATAIN

RESET

MUTE

PORA

PORT2

PORM

19

1524738

18

NICAM 728 DECODER AND

DEVICE CONTROLLER

XTAL

OSC

50

42

41

SDA

OSC

VSSX

DIGITAL FILTER, GAIN,

IIC

DAI

246

51

49

SCL

DOBIA

ADSEL

EXT-L

EXT-R

6

SAA7283ZP

NOISE SHAPER

(RIGHT CHANNEL)

DE-EMPHASIS

NOISE SHAPER

(LEFT CHANNEL)

44 12

VSSD

VDDD

VSSDAC

7

OUTPUT SWITCHES

BITSTREAM DAC

9RIGHT CHANNEL)

BITSTREAM DAC

(LEFT CHANNEL)

161734

AND BUFFER

OUTPUT SWITCHES

AND BUFFER

(LEFT CHANNEL)

EXTL

VSSA

VDDA

(RIGHT CHANNEL)

11

VROA

REPRESENTS CONTROLLER BUS

8

15

5

VRCA

OP-R

OP-L

V

i1

AF1

250mV RMS (from 1st SC)

250mV RMS (from 2nd SC)

AF2

V

i2

CDCL

CAGC

CLP

Vipil

7

8

LEVEL

5

4

2 3

-2dB 0 to 4.5dB

-2dB

0 to 4.5dB

STEREO

LEVEL AND STEREO ADJUSTMENT

0 to 4.5dB

A/MONO

250MV RMS

TDA9840

DIGITAL PLL

OSCILLATOR

19

XTAL

CD1

L/A/MONO 250MV RMS

L

R/B

DIGITAL PLL AND DEMODULATOR

DITAL PLL AND DEMODULATOR

GENERATION

VREF

OF REFERENCE VOLTAGES

1/2 Vp

CD2

15 17 9

6

18

Vi3

Vi4

500mV RMS

10

MUTE

DIGITAL INTEGRATOR

POWER-ON RESET

16

GND

6dB

DUAL bit

STEREO bit

CONTROL LOGIC

500mV RMS

IIC BUS CONTROL

14

13

12

11

20

V o1

MAIN

Vo2

V o3

SCART

Vo4

SCL SDA

1

Vp

-12-

F2HT

TDA8424 <SOUND CONTROLLER>

MM1369AD <3D SURROUND PROCESSOR>

L-IN

R-IN

1

3

MODE

SELECTOR

TDA8424

mono

stereo/spatial

stereo/mono

spatial

stereo/mono

stereo/spatial

Vcc

mono

spatial

POWER SUPPLY

GND

bass L

16

Vcap

15

SDA

bass R

6

IIC BUS

7

volume

1211254

treble L

14

bass

balance

10

D.GNDSCL

treble R

8

13

L-OUT

treble

9

R-OUT

Vcc Lin Gl1 Gl2 Gl3 Gl4 Fc Qf1 Qf2 Qf3 Qf4 Lout

24 23 22 21 20 19 18 17 16 15 14 13

SIMULATED STEREO

MM1369AD

SIMULATED STEREO

1 2 3 4 5 6 7 8 9 10 11 12

Rin Gr1 Gr2 Gr3 Gr4 M/g Ref SPC Qi S/Q Rout Gnd

gm

VIRTUAL AUDIO QXPANDER PROCESSOR

SERVICE CONTROL ADJUSTMENTS

Main Board

IC801 CPU

C673

C671

671

OARD

C805

SERVICE

C806

SUB VIDEO BOARD

BACK BOARD

IC802 MEMORY

C810

K2E

NORMAL

SW220 SERVICE SWITCH

R014

X801

TP-D

C218

C205

C275

Q809

Q808

TP-E

K8H

K2L K2M

C013

Q134

X127

C138

IC101 IF /VIDEO/COLOUR/ DEF.

X127

C375

C371

VR371 H-CENTRE

KOE

X126

X101

C009

T121 AFT

C104

C050

C012

1C3431

VR120 AGC

C003

SIF BOARD

C131

KIG

C010

C006

C003

C002

C103

C101

A101 TUNER

NICAM/STEREO BOARD

C102

TP-A

K2A

K2B

Grey Scale Adjustment

AFT ADJUSTMENT

1. Receive the clearest station.

2. By using T121, adjust AFT to obtain the best picture.

AGC ADJUSTMENT

NOTE:

weak signal.

1. Receive the clearest station.

2. Set AGC VR(VR120) in direction which causes

Do not attempt this adjustment with

snow noise to appear, then in the opposite direction until snow noise just disappears.

H-CENTRE ADJUSTMENT

1. Receive circular pattern signal.

2. Adjust H-centre by using VR371.

CRT Board

Q706

K17J

K17P

K27B

BLUE OUT

K761

Q782

RED OUT

GREEN OUT

K27V

Q762

Q772

Q152

Q781

Q101 Q180

Q761

K7Y

Q153

Q771

K27E

C792

VR782 BLUE BIAS

VR762 RED BIAS

VR772 GREEN BIAS

VR781 BLUE DRIVE

VR761 RED DRIVE

GREYSCALE ADJUSTMENT

[SCREEN VR ADJUSTMENT]

1. Receive white pattern signal.

2. Set brightness and contrast controls to maximum.

3. Set VR761 and VR781 to be mechanical centre.

4. Turn VR762, VR772 and VR782 fully counterclockwise.

5. Turn SW220 to “SERVICE” mode.

6. Set screen VR for one colour to be just visible.

[BIAS VR ADJUSTMENT]

7. By using VR762, VR772 or VR782, adjust line to be white.

8. Turn SW220 to “NORMAL” mode.

[DRIVE VR ADJUSTMENT]

9. By using VR761 and VR781, adjust white balance.

F2HT

-13-

SERVICE CONTROL ADJUSTMENTS

Power & Deflection Board

K6G

L633

C491

C402

T401

C481

Q633 POWER DRIVE

Q402

K4H

C633

Q634 POWER SWITCH Q632

L461

Q403 HORIZ. OUTPUT

K4C

FOCUS

R426

T402 FLYBACK TRANS.

T611 CONVERTER TRANS.

L425

Q631

K4A

SCREEN

L704

K4S

C486

IC611

C482

Q616

Q461

IC423

Q461

C521

L462

L502

Q462

C624

C616

Q615

C506

C504

C618

IC501 VERT. DEF.

K6D

HORIZ DRIVE TRANS.

C652

C531

Q531

IC531

C621

Q614

DOWN

C542

IC651

Q505

UP

C512

C651

Q501

SW501 V-CENTRE

C546

IC481

K6A

KB4

K4E

Q542

Q541

C543

V-CENTRE ADJUSTMENT

1. Receive circular pattern signal.

2. Adjust V-centre by using SW501.

FOCUS ADJUSTMENT

By using FOCUS VR, adjust focus control for well scanning lines.

HIGH VOLTAGE

[HIGH VOLTAGE ADJUSTMENT]

1. Receive circular pattern signal.

2. Set brightness to centre and contrast to maximum.

3. Connect a high voltage meter to CRT anode.

4. Confirm high voltage to be 30.5 ±1 KV, and less than 34.0KV at 0 beam current.

Sub Video Board

TP1311

C2512

C2511

IC2501 BLACK LEVEL ADJ.

K20J

X1301

C1318

VR1301

IC1303 SUB CPU

IC1302

C1335

K20H

TP1310

C1324

IC1301

C1301

VR1302

C1331

-14-

H-BLANKING ADJUSTMENT

NOTE:

1. Receive circular pattern signal.

2. Set screen mode to NORMAL.

3. Adjust right and left blanking width to be equal by

This must be done after picture size

adjustment.

using VR1301(right) and VR1302(left).

F2HT

DC 12.0V AGC voltage (4.3-4.5V) Output probe

Input probe DC5.0V Marker frequency Sweep ATT

0dB=176mVrms/75

Tool A

SETTING

K3A-pin5 IC101-pin48 IC101-pin45 (Side b) IC101-pin7 KOC-pin8

38.9/39.5MHz 20dB

IC101-pin46 and GND

Adjustment

By using T121, adjust "P" to be maximum amplitude.

Waveform

CIRCUIT ALIGNMENTS

VIF ALIGNMENT

Input probe

Output probe

SIF ALIGNMENT

DC 12V AGC voltage Output probe

Input probe Sweep ATT Marker Frequency

SETTING

IC3801-pin11 IC3801-pin3 IC3801-pin1 (Side b) IC3801-pin12 10dB

38.9/39.5MHz

Adjustment

1. Adjust AGC voltage to be "A" = 0.5Vp-p.

2. By using T3801, adjust "P" to be equal centre line.

Waveform

Tool A: 0.01uF

Tools

Marker frequency

39.5MHz --> C28WN1B

38.9MHz --> C28W1/WN1

-15-

F2HT

SIF Board

VIF Alignment

SIF Alignment

MAIN Board

Q134

MAL

75

C218

Q808

C205

TP-E

K8H

Q809

X126

X127

C138

IC101 IF /VIDEO/COLOUR/ DEF.

X127

C375

C371

VR371 H-CENTRE

X101

C104

C050

T121 AFT

1C3431

VR120 AGC

SIF BOARD

C131

A101 TUNER

C103

C101

NICAM/STEREO BOARD

C102

K2A

K2B

10kΩ

0.002µF

75Ω

1kΩ

a b

P

0.01

K2L K2M

C3807

T3801

KIG

X3801

TP-A

P

"A"

K38H2

IC3801

K38H2

CIRCUITALIGNMENTS

PILOT ALIGNMENT

SETTING

Oscilloscope Input sound signal source

TV system Deviation Mode

NICAM&Stereo Board

C3414

X3401

IC3451

IC3401

TJ3401

L3454

C3478

X3461

C3467

C3469

C3472

C3462 C3464

C3433

C3431

C3432

C3495C3488

1C3431

C3482

C3484 C3485

C3486 C3492

C3494

C3409

C3405

C3408

IC3401-pin5 System B/G

27kHz Stereo

Pilot Alignment

Required only model C28W1/WN1

Not Required model C28WN1B

Adjustment

By using T3401, adjust amplitude to be maximum.

Waveform

A

K34B

K34A

F2HT

-16-