PANORAMIC GMTV20M Schematic

SERVICE MANUAL Colour Television

Product Code: 111342117

Original Ver sion

Chassis Series: LA5-A

F8GW

FILE NO.

Model No. GMTV20M

Service Ref. No.GMTV20M-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 ✕ 2 (436mVr ms, more than 40KΩ)

Headphone Jack (Mono) ✕ 1

Sound Output (RMS) . . . . 2W

Speakers . . . . . . . . . . . 5 cm x 9 cm x 1 pc.

Dimensions . . . . . . . . . 496 (W) ✕ 464 (H) ✕ 472 (D)mm

Weight . . . . . . . . . . . . . approx.16.7 Kg

Specifications subject to change without notice.

CH

VOL

MENU

VIDEO

AUDIO

JXMRR

Contents

-2-

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

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

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

Service Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-14

Purity and Convergence Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Cabinet Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Chassis Electrical Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-23

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 .

-3-

Chassis Block Diagrams

MAIN SIGNAL PROCESSING CIRCUIT

T611B

Q432

IC501

LA78040

VERT-OUT

T471

HV

IC802

5

6

3

4

TUNER

SAW

IC201

LA76818A

AUDIO AMP.

IC001

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

42

EXT VIDEO IN

K1001

K1002A

REAR AV IN

FRONT AV IN

VIDEO

AUDIO

19

20

21

R

G

B

7

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

EXT AUDIO IN

LA4266_2W

1

AUDIO OUTPUT

51

5

Q901

CRT

IF/VIDEO/CHROMA/DEFLECTION

(WITH PLL)

FILTER

MEMORY

IIC BUS CONTROL

15

C-CAPTION IN

40

SELECTED VIDEO OUT

IC801

CPU

QXXAVC479P

SP901

K1921

HEADPHONE JACK

DEFLECTION YOKE

-4-

Chassis Block Diagrams

SYSTEM CONTROL

IC802

IC801

CPU

QXXAVC479P

5

6

3

4

SDA

SCL

31

19

20

21

22

1

2

MEMORY

15

17

27

6

18

10

12

13

29

23

28

7

CPU OSC IN

OSC

CPU OSC OUT

SOUND MUTE OUT

(ACTIVE=HIGH)

IC001

AUDIO AMP.

RESET IN (RESET=LOW)

KEY

SWITCH

KEY SWITCH IN

RC PRE-AMP

RC SIGNAL IN

RELAY ON/OFF OUT FOR DEGAUSSING

(ON=HIGH)

POWER ON/OFF OUT

LED

(RED)

POWER CIRCUIT

SDA

SCL

A101

TUNER

IC201

IF/VIDEO/CHROMA

DEFLECTION

CIRCUIT

POWER CIRCUIT

etc.

AFT S-CURVE IN

C-CAPTION IN

OSD BLK OUT

OSD RED OUT

OSD GREEN OUT

OSD BLUE OUT

HORIZ. SYNC. IN

VERT. SYNC. IN

POWER PROTECT IN

(POWER ERROR=LOW)

(STANDBY=LOW)

-5-

IC Block Diagrams

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

-6-

IC Block Diagrams

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

0.1u

VCO

Filter

+

0.47u

Audio.out

+

Audio in

10u

Video

Out

FM

Filter

+

1u

FM

Out

0.01u

+

to BUS Line

+

-7-

IC Block Diagrams

IC001 < Audio AMP. > LA42052-E

1

2

3

PRE GND

4

6

7

8

9

NC

10

AMP

5

POWER GND

NC

FILTER

NC

VCC

INPUT

OUT PUT

NFL

30KΩ

300Ω

Thermal

Protection

-

+

AMP

Pump

Up

1

INVERTING

INPUT

2

Vcc

3

PUMP UP

OUT

4

GND

5

Ver. OUTPUT

6

OUTPUT

STAGE Vcc

7

NON INV.

INPUT

IC501 < Ver tical Output > LA78040N, TDA9302H

-8-

Service Adjustments

VOLUME +

VOLUME

-

CHANNEL UP

CHANNEL DOWN

MENU

CH

MENU

S1.00110000 S2.01111000

ADDRESS DATA

02 H-PHA 08

Item No.

Item

Data value

General

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

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.

[ Service Mode Display ]

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.

IC802 (EEPROM) Replacement

When IC802 (EEPROM) is replaced, IC801 (CPU) will automatically write the initial reference data into IC802 for basic TV operation. However, the bus data should be checked and some bus data should be set up before attempting the service adjustments. (See pages 9 ~ 10 for detailed information.)

Initial Bus Data Setup

Note: When IC802 (EEPROM) is replaced, following Service Menu should be set up for proper TV operation before attempting the

service adjustments.

NO.01 RFAGC (Adjust the data 06 to10) NO.82 CHMT (Adjust the data 12 to 05) NO.308 R08 (Adjust the data FF to 21) NO.05 V-SCO (Adjust the data 17 to 11) NO.84 RELAY (Adjust the data 80 to 20) NO.309 R09 (Adjust the data FF to 95) NO.06 V-LIN (Adjust the data 15 to 16) NO.85 CCD (Adjust the data 26 to 31) NO.310 R10 (Adjust the data FF to 50) NO.11 VLI60 (Adjust the data +1 to 0) NO.300 R00 (Adjust the data FF to 93) NO.311 R11 (Adjust the data FF to 00) NO.19 RDRIV (Adjust the data 63 to 64) NO.301 R01 (Adjust the data FF to 0E) ↓↓ NO.20 GDRIV (Adjust the data 07 to 08) NO.302 R02 (Adjust the data FF to 00) NO.371 R71 (Adjust the data FF to 00) NO.21 BDRIV (Adjust the data 63 to 64) NO.303 R03 (Adjust the data FF to 00) NO.372 R72 (Adjust the data FF to A2) NO.24 B-YD (Adjust the data 10 to 08) NO.304 R04 (Adjust the data FF to 01) NO.25 R-YD (Adjust the data 10 to 08) NO.305 R05 (Adjust the data FF to 00) NO.68 AFCAV (Adjust the data 00 to 01) NO.306 R06 (Adjust the data FF to 00) NO.81 POMT (Adjust the data 12 to 08) NO.307 R07 (Adjust the data FF to 00)