NOBLEX 21TC657 Service Manual

SERVICE MANUAL Colour Television

Product Code: 111354912

Original Ver sion

Chassis Series: LA5-A

C4BP

FILE NO.

Model No. 21TC657

Service Ref. No.21TC657-00

(Argentina)

Give complete “SERVICE REF. NO.” for parts
order or servicing. It is shown on the rating
plate at the cabinet back of the unit.

This T.V. receiver will not work properly in
foreign countries where the television trans­mission system and power source differ from
the design specifications.Refer to the specifi­cation table.

Specifications

Power Source . . . . . . . . .AC220V, 50Hz / 60Hz

Receiving System . . . . . .PAL (M/M, N/N), NTSC (M/M)

Channel Coverage

Antenna mode VHF:CH02-CH13, UHF: CH14-CH69

CATV mode VHF band:CH01-CH13, Mid band: CH14-CH22

Super band: CH23-CH36, Hyper band: CH37-CH64
Ultra band: CH65-CH94 and CH100-CH125

Low mid band: CH95-CH99

Video IF . . . . . . . . . . . . . 45.75MHz

Aerial Input Impedance . . 75Ω
Ext.Terminals

Video inputs: Phono jack ✕ 2 (1Vp - p, 75Ω)
Audio inputs: Phono jack (R/L) ✕ 2 (436mVr ms, more than 40KΩ)

Headphone Jack: Mini stereo jack ✕ 1

Sound Output (RMS) . . . . 3W + 3W

Speakers . . . . . . . . . . . 5 cm x 9 cm x 2 pcs.

Dimensions . . . . . . . . . 606 (W) ✕ 479 (H) ✕ 483 (D)mm

Weight . . . . . . . . . . . . . approx.21.0 Kg

Specifications subject to change without notice.

NOBLEX

NOBLEX

1AV0U10B22200

JXMMA

POWER

A

U

D

IO

M

O

D

E

V

ID

E

O

M

O

D

E

5

9

6

3

0

2

8

7

4

1

SURROUND

MENU

VOL

VOL

CH

CH

NOBLEX

IMAGE

DISPLAY

MUTE

SLEEP

REC

ALL

SOUND

NOBLEX

Contents

-2-

Safety Notice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Chassis Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

IC Block Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7

Service Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-16

Purity and Convergence Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Cabinet Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Chassis Electrical Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-26

Safety Notice

SAFETY PRECAUTIONS

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 primar y of the
converter transformer of the set.

2: Comply with all caution and safety-related notes pro-

vided 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.

X-RADIATION PRECAUTION

The primary source of X-RADIATION in 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 v olt po w er supply adjustment, and high volt­age check 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 par ticularly recommended that only par ts 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 .

Chassis Block Diagrams

-3-

T611B

Q432

IC501

VERT-OUT

T471

HV

IC802

IC801

CPU

QXXAVC479P

5

6

3

4

TUNER

SAW

IC201

LA76818AM

IC3401

CXA2134QP

IC002

LA42052-E

AUDIO AMP

SDA

SCL

ON-TIME

STANDBY

RGB

BLK

OSD

32

31

19

20

21

22

SDA

SCL

1

2

X161

A101

ANT

IF IN

5/6

SCL

SDA

R

G

B

BLK

12

11

14 15

16 17

13

34 33

3

4

4

2

42

FM OUTPUT

EXT VIDEO IN

K1001

K1002

REAR AVIN

FRONT AVIN

VIDEO

VIDEO

A-L

A-L

A-R

A-R

19

20

21

R

G

B

K1921

12

8

AC

POWER

CIRCUIT

CONVERTER

TRANS

130V(MAIN HIGH)

20V(AUDIO)

12V(MAIN LOW)

24V(VERT)

9V

IC202

REG.IC

5V-2

REG.IC

IC681

5VRC

2723

HORIZ-OUT

FBT

VERT.OUT

HORIZ.OUT

AUDIO RIGHT

AUDIO LEFT

HEADPHONE JACK

Q900

CRT

MEMORY

5/6

MTS DECODER/AUDIO CONTROL&SW

IIC BUS CONTROL

(WITH PLL)

FILTER

IF/VIDEO/CHROMA/DEFLECTION

DEFLECTION YOKE

2

R

L

15

C-CAPTION IN

40

SELECTED VIDEO OUT

MAIN SIGNAL PROCESSING CIRCUIT

Chassis Block Diagrams

-4-

SYSTEM CONTROL

QXXAVC479P

15

C-CAPTION IN

IC Block Diagrams

-5-

IC201 < IF/Video/Chroma/Def. > LA76818A

1

DC

VOL

SW

FM

DET

2

3

4

56

IF

AGC

RF

AGC

VIF

7

8

9

10

IF

VCC 5V

11

12

13

BUS

PEAKING

CORING

BLACK

STRETCH

SYNC

SEP

14

15

ABL

DC

REST

CLAMP

OSD

CONTRAST

BRIGHT

16

17

18

19 20

CONTRAST

BRIGHT

RGB

MATRIX

OSD

SW

DRIVE/OUT-OFF

VCC

21

22

23

FSC/

SYNC SW

24

25

26 27

VER

RAMP

HOR

VCC

H

VCC

VER

C/D

HOR

OUT

PHASE

SHIFTER

AFC2

AFC1

VER

SEP

HOR

C/D

1/256

COLOR

CLAMP

LPF

ALC

+

SW

CLAMP

DEMO

PAL

SW

ACC

BPF

ON/OFF

DELAY

LINE

SW

TRAP

AFT

VIDEO

DET

TRAP

LIM

AMP

BPF

SPLL

BPF

VIDEO

AMP

IF

IDENT

VIDEO

SW

APC1

TINT

VXO

DDS

APC2

DC ADS.

CLAMP

VCO

1H DELAY

HOR

VCO

FBP

2829

30

31

32

1H

VCC

33

34

353637

38

39

40

41

42

CLMP

43

4445

CLMP

V/C VCC

5V

46

47

48

4950

A2C

PLL

51

525354

Audio Output

FM Output/Selected
Audio Output

PIF AGC

RF AGC Output

PIF Input1

PIF Input 2

IF Ground

IF Vcc

FM Filter

AFT Output

Bus Data

Bus Clock

ABL

Red Input

Green Input

Blue Input

Fast Blanking Input

RGB Vcc

Red Output

Green Output

Blue Output

fsc output or C
Sync output

Vertical Output

Ramp ALC Filter

Horizontal/BUS Vcc

Horizontal Output

Horizontal AFC Filter

Flyback Pulse Input

VCO IREF

Clock (4MHz) Outupt

CCD Vcc

CCD Filter

CCD/Horizontal Ground

SECAM B-Y Input
(Cb Input)

SECAM R-Y Input
(Cr Input)

Chroma APC2 Filter

Clamp Filter

4.43 MHz Crystal

Chroma APC1 Filter

Selected Video Output

Video/Vertical/BUS Ground

External Video Input(Y-IN)

Video/Vertical Vcc

Internal Video Input (S-C IN)

Black Level Detector

Video Output

VCO Filter

VCO Coil 2

VCO Coil 1

APC Filter

Ext. Audio Input

SIF Output

SIF APC Filter

SIF Input

IC Block Diagrams

-6-

IC201 <IF System Block Diagram> LA76818A

11

12

BUS

Interface

SAW

5

6

4

8

7

PIF

In1

PIF

In2

IF In

9V

30K

RF AGC

Out

120K

IF VCC

IF

GND

VIF AMP

VIF 1

VIF 2

VIF 3

IF AGC

Drive

RF

AGC

2ndIF

AGC

RF AGC

Delay

6bit

IF AGC

Def

1bit

+

-

(6 Vcc)/7

To

BUS

3

0.022u

PIF

AGC

IF

AGC

Data

Clock

APC

Det

+π/4

-π/4

Snd

Det

Amp

52

SIF.Out

Sound

Trap

Video

Det

Buzz

Canceller

50

APC

Filter

330

0.47u

+

PLL Pull-in SW

To

BUS

Lock

Det

Video.Level

3bit

Amp

54

10p

SIF.In

Sound

BPF

VCO.Coil

VCO

COIL1

VCO

COIL2

48

49

VIF

VCO

Chroma

Counter

B/N

INV

IF

Ident

OSC

C/D

Amp

SIF. Sys

2bit

pre-

scaller

SIF

VCO

500K

BPF

SIF

APC

Filter

1K

0.01u

1000p

53

LIM

AMP

FM

Det

FM.Level

5bit

Chroma

C/D

APC

Det

500K

Det

To

BUS

Chroma

VCO

VIF

Counter

Reset

Pulse

VCO

Ident

VIF.Sys

2bit

Phase

Detector

A.MUTE

1bit

VOLUME

D/A

VOLUME

Filter

A.SW

1bit

Input

Select

VOLUME

(ATT)

-

+

-

+

2.5V

Amp

FM Gain

1bit

Deem-TC

1bit

De-

emph

FM Mute

1 bit

2

9

46

51

1

A.Fil.Def

1bit

VOLUME

7bit

47

VCO

Alignment

AFT

10

AFT

Vcc

100K

100K

0.1u

VCO

Filter

+

0.47u

Audio.out

+

Audio in

10u

Video

Out

FM

Filter

+

1u

FM

Out

0.01u

+

to BUS Line

+

IC Block Diagrams

-7-

IC002 < Audio AMP. > LA42052-E

Thermal

Protection

-

+

AMP

Pump

Up

1

INVERTING

INPUT

2

Vcc

3

PUMP UP

OUT

4

GND

5

Ver. OUTPUT

6

OUTPUT

ST A GE Vcc

7

NON INV.

INPUT

IC501 < Ver tical Output > LA78040N, TDA9302H

10

11

LFLT

VCO

12

PCINT1

PCINT2

PLINT

13

VCA

LPF

FLT

19

COMPIN

Vcc

17

Analog Block GND

23NOISETC

18

SAPTC

14

15

VGR

IREF

IREF

7

6

5

I

2

C BUS I/F

Digital Block GND

SCL

SDA

SAPIND

NOISE

DET

SAPVCO

BPF

STIND

1/4

1/2

LPF

DeEm

LPF

LPF

DeEm

AMP

(+4dB)

LPF

SW

24

25

22

SAPOUT

SAPIN

STIN

26 27

28

VE

VEWGT

LPF

HPF

LOGIC

NRSW/FOMO/SAPC

VCA

21

9

SUBOUT

(L-R signal output)

MAIN OUT

(L+R signal output)

8

MATRIX

VE

VCA

RMSDET

RMSDET

29

30 32 31

1

VETC

VEOUT

VCAIN

VCAWGT

VCATC

TREBLE OUT-L

SPECTRAL

34

33

FEXT1

TVSW

EXT1/EXT2/M1

M2

SURR

SURROUND

BASS

BASS

TREB

BASS

TREBLE

TREB

VOL-L

VOL-L

VOL-R

48

VOLIN-L

4

LSOUT-L

3

LSOUT-R

VOL-R

VOLUME RIGHT
CHANNEL INPUT

43

44

TREBLE OUT-R

41

47

TREBLE FILTER-L

45

2

BASS FILTER-L

40

SURRTC

38

TVOUT-R

39

TVOUT-L

36

37

AUX2-L
(Left channel
external input)

FEXT2

INPUT PIN OF (L+R)

SIGNALFROM

MAIN OUT(PIN9)

(+6dB)

WIDEBAND

"STEREO"

"NOISE"

"SAP"

"PONRES"

ATT/ATTSW

BASS FILTER-R

(Stereo block

PLL loop filter

integrating

pin)

(Pilot cancel

circuit loop filter

intergrating pin)

(Audio multiplexing
signal input)

AUX2-R
(Right channel
external input)

TREBLE FILTER-R

AUX1-L(Left channel

external input)

AUX1-R(Right channel

external input)

(Band gap reference

output)

(Sap FM detector

output)

(Input of L-R signal

from SUBOUT)

(Input of SAP signal)

(Variable de-

emphasis

integrating pin)

(Variable de-emphasis

output pin)

IC3401 < MTS Decoder, Audio Control & Switch > CXA2134QP

1

2

3

PRE
GND

4

6

7

8

IN2

10

AMP

5

POWER
GND

IN1

RIPPLE
FILTER

P.P

VCC

STANDBY

OUT2

12

OUT1

AMP

INPUT AMP. OUTPUT AMP.

THERMAL
PROTECTION
CIRCUIT

AMP AMP

AMP

REF AMP.

RIPPLE FILTER

BLOCK

POP NOISE PREVENTION

BLOCK

INPUT AMP. OUTPUT AMP.

VIDEO MODE

MENU

VOL

VOL

CH

CH

IMAGE

VIDEO MODE

MENU

VOL

VOL

CH

CH

IMAGE

-8-

Service Adjustments

General

This set has an On-screen Service Menu system includ­ed in the CPU thar allows remote operation for most of
the service adjustments.

Service Adjustment-1

1. Enter the Service Menu

While pressing the MENU button on the televi­sion, press the Number Key 2 on the remote control
unit.The Service Menu now appear.

2. Service Adjustments:

Press the CHANNEL UP or CHANNEL DOWN
button on the remote control handset to select the
desired service menu item you want to adjust.

Use the VOLUME + or-to adjust the data.The + or

-

button will increase or decrease the data

sequentially.

3. Exit from the Service Menu

Press the MENU button to turn off the Service Menu
display.
The data which is set in the service mode is stored
into the memory IC automatically.

[ Entering the Service Menu ]

VOLUME +

VOLUME

-

CHANNEL UP

CHANNEL DOWN

[ Service Adjustment ]

[ Exit from the Service Menu ]

S1.00100111 S2.11111000

ADDRESS DATA

02 H-PHA 08

Item No.

Item

Data value

[ Service Mode Display ]

POWER

3

21

MENU

-9-

Service Adjustments

No. Item Initial value Range Description

01 RFAGC 06 00~63 RF AGC adjustment
02 H-PHA 08 00~31 H-PHASE adjustment (50Hz)
03 V-POS 32 00~63 Vertical position adjustment (50Hz)
04 V-SIZ 54 00~127 Vertical size adjustment (50Hz)
05 V-SCO 17 00~31 Vertical-S compensation (50Hz)
06 VLIN 15 00~31 Vertical linear ity adjustment (50Hz)
07 H-P60 +4 -16~+15 Difference value of H-PHASE adjustment (60Hz)
08 V-P60 0 -32~+31 Difference value of V-POSITION adjustment (60Hz)
09 V-S60 +1 -64~+63 Difference value of V-SIZE adjustment (60Hz)
10 VSC60 0 -16~+15 Difference value of Vertical-S compensation (60Hz)
11 VLI60 +1 -16~+15 Difference value of Vertical linearity adjustment (60Hz)
12 OSDHP 30 01~255 OSD hor izontal remark position
13 OSDC 50 00~127 OSD contrast
14 V-SCP 07 00~07 V-SIZE COMP (50Hz)
15 SBIAS 70 00~127 Sub Bias adjustment
16 RBIAS 00 00~255 Red Bias adjustment
17 GBIAS 00 00~255 Green Bias adjustment
18 BBIAS 00 00~255 Blue Bias adjustment
19 RDRIV 63 00~127 Red Dr ive adjustment
20 GDRIV 07 00~15 Green Drive adjustment
21 BDRIV 63 00~127 Blue Drive adjustment
22

-- -- --

White balance (a lateral line)

23 DRV

-- --

Brightness and dark of White balance adjustment
24 B-YD 10 00~15 B-Y DC Level
25 R-YD 10 00~15 R-Y DC Level
26 B-YND 0 -16~+15 Difference value of NTSC B-Y DC Level
27 R-YND 0 -16~+15 Difference value of NTSC R-Y DC Level
28 G-YA 00 00,01 G-Y Angle
29 RBGB 08 00~15 R-Y/B-Y Gain Balance
30 RBAG 08 00~15 R-Y/B-Y Angle
31 G-YAN 00 00,01 Difference value of NTSC G-Y Angle
32 RBGBN 0 -8~+7 Difference value of NTSC R-Y/B-Y Gain Balance
33 RBABN 0 -8~+7 Difference value of NTSC R-Y/B-Y Angle
34 COGV 01 00~03 Cor ing gain
35 BLK 03 00~03 BLK. STR. Star t (W/Defeat)
36 BLKG 03 00~03 BLK. STR. Gain
37 BRTA 00 00, 01 BRT. ABL Defeat
38 BRST 00 00, 01 Mid. Stp. Defeat
39 BRTH 00 00~07 Bright.ABL. Threshold
40 WPL 00 00~03 WPL Ope. Point (W/Defeat)
41 YGAM 00 00~03 Y Gamma Start
42 PORW 00 00, 01 AV Mode Pre/Over SW
43 PORS 02 00~03 AV Mode Pre/Over-shoot adjustment
44 RFCO 0 00~03 Difference Value of RF Corring Gain
45 PORWN 01 00, 01 RF Pre/Over SW
46 PORSN 03 00~03 RF Pre/Over-shoot adjustment
47 TINT 0 -16~+15 Tint
48 SHRF 0 -16~+15 Difference Value of RF Sharpness
49 TEXC 08 00~127 OSD Text Contrast
50 AUFL 00 00, 01 Auto.Fresh

On-screen Service Menu

Following table shows the initial values which have been stored in the CPU ROM, and items for the service
adjustments.

To be continued.