Sharp 20GT15 Schematic

SERVICE MANUAL

S30X520GT-15/

COLOUR TELEVISION

Chassis No. UA-1

20GT-15

COLOUR TELEVISION

• FEATURES ...................................................................................................................................................... 2

• SPECIFICATIONS ........................................................................................................................................... 2

• IMPORTANT SERVICE NOTES ...................................................................................................................... 3

• ADJUSTMENT PRECAUTION......................................................................................................................... 3

• UA1 HOTEL MODE APPLICATION ................................................................................................................. 4

• SERVICE MODE.............................................................................................................................................. 4

• TROUBLE SHOOTING TABLE...................................................................................................................... 18

MODEL 20GT-15

• SOLID STATE DEVICE BASE DIAGRAM ..................................................................................................... 20

• CHASSIS LAYOUT ........................................................................................................................................ 21

• BLOCK DIAGRAM ......................................................................................................................................... 22

• WAVEFORMS................................................................................................................................................ 25

• SCHEMATIC DIAGRAM

• DESCRIPTION OF SCHEMATIC DIAGRAM ................................................................................................. 26

■ INFRARED REMOTE CONTROL UNIT ....................................................................................................27

■ TUNER ...................................................................................................................................................... 28

■ CRT UNIT.................................................................................................................................................. 29

■ MAIN UNIT ................................................................................................................................................ 30

• PRINTED WIRING BOARD ASSEMBLIES.................................................................................................... 32

• REPLACEMENT PARTS LIST

■ ELECTRICAL PARTS................................................................................................................................ 37

■ SUPPLIED ACCESSORIES ...................................................................................................................... 41

■ PACKING PARTS...................................................................................................................................... 41

■ CABINET PARTS ...................................................................................................................................... 41

MODEL

In the interests of user-safety (Required by safety regulations in some countries) the set should be restored to its original condition and only parts identical to those specified be used.

CONTENTS

20GT-15

Page

WARNING

The chassis in this receiver is partially hot. Use an isolation transformer between the line cord plug and power receptacle, when servicing this chassis. To prevent electric shock, do not remove cover. No user – serviceable parts inside. Refer servicing to qualified service personnel.

SHARP CORPORATION

20GT-15

SPECIFICATIONS

Depth: 479.0 mm

Height: 476.0 mm

Weight (approx.): 17.2 kg

Convergence...........................................................................Self Converging System

Focus .............................................................................Quadra-Potential Electrostatic

Sweep Deflection ............................................................................................Magnetic

Intermediate Frequencies

FEATURES

5.74 MHz .......................................................................................33.16 MHz

5.50 MHz .......................................................................................33.40 MHz

Picture IF Carrier.......................................................................................38.9 MHz

Sound IF Carrier Frequency

Colour Sub-Carrier Frequency................................................................34.47 MHz

Power Input ............................................................................ 110 - 240V AC 50/60 Hz

Power Consumption..............................................................................................75 W

Size .................................................................................................. 5 × 9 cm (1 pc)

Audio Power Output Rating...................................................................3.0 W (at Max.)

Speaker

Voice Coil Impedance ................................................................ 16 ohms at 400 Hz

VHF/UHF ................................................................................. 75 ohm Unbalanced

Aerial Input Impedance

Receiving System ................................................................................. CCIR/PAL B, G

Tuner Ranges

» VHF-Channels............................ E2 (48.25 MHz) thru E12 (224.25 MHz)

» UHF-Channels........................ E21 (471.25 MHz) thru E69 (855.25 MHz)

Dimensions ........................................................................................ Width: 506.0 mm

Cabinet Material ........................................................................................... All Plastics

Specifications are subject to change without prior notice.

Favourite Channel

Full Auto Channel Preset and Auto Channel Skip

100-CH Program MemoryËCATV (Hyper Band) Ready 〈Used Frequency Synthesizer Tuner〉ËAVL (Sound Keeper) Function

Black Stretch Circuit

On Timer/Sleep Timer/Reminder TimerËBlue Back Noise Mute

Rear AV - In/Out TerminalsËColour-Comb Filter (NTSC Only)

High Contrast Picture

Hotel Mode

English/Thai OSD

20GT-15

SPECIFICATIONS

Depth: 479.0 mm

Height: 476.0 mm

Weight (approx.): 17.2 kg

Convergence...........................................................................Self Converging System

Focus .............................................................................Quadra-Potential Electrostatic

Sweep Deflection ............................................................................................Magnetic

Intermediate Frequencies

FEATURES

5.74 MHz .......................................................................................33.16 MHz

5.50 MHz .......................................................................................33.40 MHz

Picture IF Carrier....................................................................................... 38.9 MHz

Sound IF Carrier Frequency

Colour Sub-Carrier Frequency................................................................34.47 MHz

Power Input ............................................................................ 110 - 240V AC 50/60 Hz

Power Consumption..............................................................................................75 W

Size .................................................................................................. 5 × 9 cm (1 pc)

Audio Power Output Rating...................................................................3.0 W (at Max.)

Speaker

Voice Coil Impedance ................................................................ 16 ohms at 400 Hz

VHF/UHF ................................................................................. 75 ohm Unbalanced

Aerial Input Impedance

Receiving System ................................................................................. CCIR/PAL B, G

Tuner Ranges

» VHF-Channels............................ E2 (48.25 MHz) thru E12 (224.25 MHz)

» UHF-Channels........................ E21 (471.25 MHz) thru E69 (855.25 MHz)

Dimensions ........................................................................................ Width: 506.0 mm

Cabinet Material ........................................................................................... All Plastics

Specifications are subject to change without prior notice.

Favourite Channel

Full Auto Channel Preset and Auto Channel Skip

100-CH Program MemoryËCATV (Hyper Band) Ready 〈Used Frequency Synthesizer Tuner〉ËAVL (Sound Keeper) Function

Black Stretch Circuit

On Timer/Sleep Timer/Reminder TimerËBlue Back Noise Mute

Rear AV - In/Out TerminalsËColour-Comb Filter (NTSC Only)

High Contrast Picture

Hotel Mode

English/Thai OSD

20GT-15

ADJUSTMENT PRECAUTION

This model’s setting are adjusted in two diff erent w ays: through the I2C bus control and

in the conventional analog manner. The adjustments via the I2C bus control include

preset-only items and variable data.

Beam current.

mode position, and the microprocessor is in input mode. (Adjustment through

the I2C bus control). (Use JWS Key to set as well).

the mode one by one.

reversibly one by one.

modified.

(OFF) position, and the microprocessor is in out of the service mode.

(1). Short JA 122 & JA 124 for 1 second and release to switch to the ser vice

1. Setting the service mode by the microprocessor.

(2). Press the CH DOWN / UP k ey on the remote controller to get ready to select

(3). Press the CH DOWN / UP key on the remote controller to select the modes

(4). Using the VOLUME UP/ DO WN ke y on the remote controller , the data can be

(5). Short JA 122 & JA 124 for 1 second and release to s witch to the normal mode

2. Factory Presetting.

mode position and turn on the main power switch. Initial values are automati-

cally preset, only when a new EEPROM is used (Judge with the first 4 b ytes).

(1). Short JA 122 & JA 124 for 1 second and release to switch to the ser vice

(2). The initial data are preset as listed in page 4, 5, & 6.

(3). Make sure the data need modify or not (Initial data).

for the FIRST TIME, make sure to short JA 122 & JA 124 to switch to the

service mode position first and then turn on the main power switch (See 2-(1)

above).

Note: Once the chassis has been assembly together and ready to be POWER ON

Precaution: If haven’t done this initiation, it may possibly generate excessive

IX3368CEN0 Attachment)

3. For reference please check with memory map (UA1 Series type RH-

IMPORTANT SERVICE NOTES

Maintenance and repair of this receiver should be done by quali-

fied service personnel only.

after discharging the high voltage completely.

1. Picture tube in this receiver employs integral implosion protection.

2. Replace with tube of the same type number for continued safety.

3. Do not lift picture tube by the neck.

SERVICE OF HIGH VOLTAGE SYSTEM AND PICTURE

TUBE

When servicing the high voltage system, remo ve static c harge from it b y

Connecting a 10K ohm Resistor in series with an insulated wire (such as

a test probe) between picture tube dag and 2nd anode lead. (AC line cor d

should be disconnected from AC outlet.)

4. Handle the picture tube only when wearing shatterproof goggles and

X-RAY

This receiver is designed so that any X-Ray radiation is kept to an abso-

lute Minimum. Since certain malfunctions or servicing may produce po-

µA) in the case of the set. The set has

µA) for the set.

± 1.5kV (at beam 1100

been factory - Adjusted to the above-mentioned high voltage.

the repairs, ne ver forget to chec k for such high v oltage after the work.

24.5kV

more than 28.7kV (at beam 0

∴ If there is a possibility that the high voltag e fluctuates as a result of

2. T o keep the set in a normal operation , be sure to make it function on

1. When repairing the circuit, be sure not to increase the high v oltage to

tentially hazardous radiation with prolonged exposure at close range ,

the following precautions should be observed:

which may cause excess X-ray radiation.

3. Do not substitute a picture tube with unauthorized types and/or brands

BEFORE RETURNING THE RECEIVER

Before returning the receiver to the user , perf orm the follo wing safety

checks.

that hardware is not lodged between the chassis and other metal parts

in the receiver.

1. Inspect all lead dress to make certain that leads are not pinched or

sulating fishpapers, cabinet bac ks, adjustment and compartment cov-

ers or shields, isolation resistor -capacity netw orks, mechanical insu-

lators etc.

2. Inspect all protective devices such as non-metallic contr ol knobs, in-

20GT-15

ADJUSTMENT PRECAUTION

This model’s setting are adjusted in two diff erent w ays: through the I2C bus control and

in the conventional analog manner. The adjustments via the I2C bus control include

preset-only items and variable data.

Beam current.

mode position, and the microprocessor is in input mode. (Adjustment through

the I2C bus control). (Use JWS Key to set as well).

the mode one by one.

reversibly one by one.

modified.

(OFF) position, and the microprocessor is in out of the service mode.

(1). Short JA 122 & JA 124 for 1 second and release to switch to the ser vice

1. Setting the service mode by the microprocessor.

(2). Press the CH DOWN / UP k ey on the remote controller to get ready to select

(3). Press the CH DOWN / UP key on the remote controller to select the modes

(4). Using the VOLUME UP/ DO WN ke y on the remote controller , the data can be

(5). Short JA 122 & JA 124 for 1 second and release to s witch to the normal mode

2. Factory Presetting.

mode position and turn on the main power switch. Initial values are automati-

cally preset, only when a new EEPROM is used (Judge with the first 4 b ytes).

(1). Short JA 122 & JA 124 for 1 second and release to switch to the ser vice

(2). The initial data are preset as listed in page 4, 5, & 6.

(3). Make sure the data need modify or not (Initial data).

for the FIRST TIME, make sure to short JA 122 & JA 124 to switch to the

service mode position first and then turn on the main power switch (See 2-(1)

above).

Note: Once the chassis has been assembly together and ready to be POWER ON

Precaution: If haven’t done this initiation, it may possibly generate excessive

IX3368CEN0 Attachment)

3. For reference please check with memory map (UA1 Series type RH-

IMPORTANT SERVICE NOTES

Maintenance and repair of this receiver should be done by quali-

fied service personnel only.

after discharging the high voltage completely.

1. Picture tube in this receiver employs integral implosion protection.

2. Replace with tube of the same type number for continued safety.

3. Do not lift picture tube by the neck.

SERVICE OF HIGH VOLTAGE SYSTEM AND PICTURE

TUBE

When servicing the high voltage system, remo ve static c harge from it b y

Connecting a 10K ohm Resistor in series with an insulated wire (such as

a test probe) between picture tube dag and 2nd anode lead. (AC line cor d

should be disconnected from AC outlet.)

4. Handle the picture tube only when wearing shatterproof goggles and

X-RAY

This receiver is designed so that any X-Ray radiation is kept to an abso-

lute Minimum. Since certain malfunctions or servicing may produce po-

µA) in the case of the set. The set has

µA) for the set.

± 1.5kV (at beam 1100

been factory - Adjusted to the above-mentioned high voltage.

the repairs, ne ver forget to chec k for such high v oltage after the work.

24.5kV

more than 28.7kV (at beam 0

∴ If there is a possibility that the high voltag e fluctuates as a result of

2. T o keep the set in a normal operation , be sure to make it function on

1. When repairing the circuit, be sure not to increase the high v oltage to

tentially hazardous radiation with prolonged exposure at close range ,

the following precautions should be observed:

which may cause excess X-ray radiation.

3. Do not substitute a picture tube with unauthorized types and/or brands

BEFORE RETURNING THE RECEIVER

Before returning the receiver to the user , perf orm the follo wing safety

checks.

that hardware is not lodged between the chassis and other metal parts

in the receiver.

1. Inspect all lead dress to make certain that leads are not pinched or

sulating fishpapers, cabinet bac ks, adjustment and compartment cov-

ers or shields, isolation resistor -capacity netw orks, mechanical insu-

lators etc.

2. Inspect all protective devices such as non-metallic contr ol knobs, in-

20GT-15

FORWARD : CH DOWN key

REVERSE : CH UP key

AGC &

GEOMETRIC

MODE

WHITE POINT

ADJ

MODE

SUB

ADJ

MODE

AGC &

GEOMETRIC

MODE

WHITE POINT

ADJ

MODE

SUB

ADJ

MODE

MISC.

OPTION

MODE

Y-DELAY

ADJ

MODE

OPTION

MODE

OFFSET

ADJ

MODE

AGC TAKE OVER POINT (AGC)

VERTICAL SLOPE (V-LIN)

VERTICAL AMP (V-AMP)

VERTICAL SHIFT (V-CENT)

HORIZONTAL SHIFT (H-CENT)

S-CORRECTION (S-COR)

W.P. RED STD. W.T. (DRI-RS)

W.P. GREEN STD. W.T. (DRI-GS)

W.P. BLUE STD. W.P. (DRI-BS)

W.P. RED COOL. W.P. (DRI-RC)

W.P. GREEN COOL. W.P. (DRI-GC)

W.P. BLUE COOL. W.P. (DRI-BC)

W.P. RED WARM. W.P. (DRI-RW)

W.P. GREEN WARM. W.P. (DRI-GW)

W.P. BLUE WARM. W.P. (DRI-BW)

MAX VOLUME (SUB-VOL)

SUB CONTRAST (SUB-CON)

SUB COLOUR (SUB-COL)

SUB BRIGHTNESS (SUB-BRI)

SUB TINT (SUB-TINT)

SUB SHARPNESS (SUB-SHP)

MAX HOTEL VOLUME (HTL-VOL)

HOTEL PROGRAM NO (HTL-PRG)

OSD GRB REFERENCE (RGB)

BLACK LEVEL OFFSET R (CUT-R)

BLACK LEVEL OFFSET G (CUT-G)

CATHODE DRIVE LEVEL (CDL)

FORWARD : CH DOWN key

REVERSE : CH UP key

* ( ) means OSD display.

SERVICE MODE

1) In the Service Mode, Key is used to select the mode in the following order.

Input 1, 3, 7, 9 by R/C key.

for hotel mode.

#1 Ch 1 is your selected channel

UA1 HOTEL MODE APPLICATION

How to enable/disable the “Hotel Mode” ?

ond press the (one/two digit) key and k eep pressing it for five second, then y ou can

Ans: a) Press the R/C (FUNCTION) key until language selection appear, within five sec-

see the hotel mode with four digits password.

mode will be enable, you can switch on/off the hotel mode by using R/C (volume

up/down) key.

b) Key in the four digits password starting with number “1”, “3”, “7”, “9”, then the hotel

HOTEL ON Set vol up/down by R/C key.

PASSWORD * * * *

Before set the hotel mode, it is better to choose ch 1 & set s-v ol lev el up to 75% full scale.

After set hotel mode, starting channel will be always ch 1 & maximum sound lev el out will

* We recommend

be set the half of full scale.

* If you set hotel mode in AV, starting channel will be the last ch which you received before

power off (same as normal operation)

When using hotel mode, user can control “contrast”, “brightness”, “sharpness” and “tint”

function.

But after power off, it will return to the initial setting.

CONDITION:

You can’t use: --

Preset mode

Fine tuning

Skip mode

System selection

The others function is allowed to be used.

20GT-15

Y-DELAY

ADJ

MODE

OFFSET

ADJ

MODE

OPTION

MODE

Y-D TIME FOR PAL (TV) (DL-PT)

Y-D TIME FOR SECAM (TV) (DL-ST)

Y-D TIME FOR N358 (TV) (DL-3T)

Y-D TIME FOR N443 (TV) (DL-4T)

Y-D TIME FOR B/W (TV) (DL-TV)

Y-D TIME FOR PAL (AV) (DL-PA)

Y-D TIME FOR SECAM (AV) (DL-SA)

Y-D TIME FOR N358 (AV) (DL-3A)

Y-D TIME FOR N443 (AV) (DL-4A)

Y-D TIME FOR B/W (AV) (DL-AV)

COLOUR OFFSET (PAL) (COL-OP)

COLOUR OFFSET (SECAM) (COL-OS)

COLOUR OFFSET (NTSC358) (COL-O3)

COLOUR OFFSET (NTSC443) (COL-O4)

SHARPNESS OFFSET (PAL) (SHP-OP)

SHARPNESS OFFSET (SECAM) (SHP-OS)

SHARPNESS OFFSET (NTSC358) (SHP-O3)

SHARPNESS OFFSET (NTSC443) (SHP-O4)

MISC.

OPTION

MODE

SOUND SYSTEM M (S-M)

SOUND SYSTEM DK (S-DK)

SOUND SYSTEM I (S-I)

SOUND SYSTEM BG (S-BG)

PLAYBACK SECAM (P-SECAM)

FF (RF) NTSC 3.58 (F-N358)

FF (RF) NTSC 4.43 (F-N443)

FF (RF) SECAM (F-SECAM)

VIDEO MUTE AT IDENT LOSS (VMI)

VIDEO MUTE AT PROGRAM

/SOURCE CHANGE (VMC)

HOTEL MODE (HTL)

REDUCED FM DEMODULATION

GAIN FOR BTSC SIGNAL (BTSC)

VERTICAL SCAN DISABLE (VSD)

BLACK STRETCH (BKS)

AUTO VOLUME LEVELING (AVL)

FAST FILTER IF-PLL (FFI)

ENABLE VERTICAL GUARD (EVG)

EHT TRACKING MODE (EHT)

OVERSCAN SWITCH OFF (OSO)

AUTO COLOUR LIMIT (ACL)

FORCED COLOUR LIMIT (FCO)

NUMBER OF EXT AV SOURCE (AV)

FM WINDOW SEVECTION (FMWS)

SOUND MUTE BIT 0 (SM0)

SOUND MUTE BIT 1 (SM1)

THAI LANGUAGE (THA)

ARABIC LANGUAGE (ARA)

MALAY LANGUAGE (MAL)

CHINESE LANGUAGE (CHI)

FRENCH LANGUAGE (FRE)

RUSSIAN LANGUAGE (RUS)

FORCED V-SYNC SLICING LEVEL (FSL)

SYNC OF OSD (HP2)

TUNER CPT (CPT)

BILINGUAL (BIL)

IF AGC SPEED BIT 0 (AGC 0)

IF AGC SPEED BIT 1 (AGC1)

FOA Time Constant-RF (FOA-FE)

FOB Time Constant-RF (FOB-FE)

FOA Time Constant-AV (FOA-AV)

FOB Time Constant-AV (FOB-AV)

*(Y-D : Y-DELAY)

The flow of Mode lists as following

Direct Key-in Step 1 Mode

RC COMMAND SERVICE-ITEM

FUNCTION AGC

CONTRAST DOWN V-LIN

COLOUR DOWN V-AMP

BRIGHTNESS DOWN V-CENT

TINT DOWN H-CENT

SHARPNESS DOWN EW//

SYSTEM HB

BLUEBACK S-COR

TIMER SUB-VOL

CONTRAST UP SUB-CON

COLOUR UP SUB-COL

BRIGHTNESS UP SUB-BRI

TINT UP TINT SUB-TINT

SHARPNESS UP SUB-SHP

CHANNEL 1 DRI-GS

CHANNEL 4 DRI-BS

CHANNEL 7 CUT-R

CHANNEL FLASHBACK

CUT-G

20GT-15

FIX/ADJ REMARK

DATA LENGTH INITIAL DATA

0 FIX

1 FIX

0 FIX

1 FIX ONLY BLK

1 FIX

0 FIX

0(DISABLE)/1(ENABLE)

0 FIX

1 FIX *3

1 FIX

1 FIX *3

0(DISABLE)/1(ENABLE)

0 FIX

1 FIX *4

1 FIX *5

1 FIX

0 FIX

0(DISABLE)/1(ENABLE)

1 ADJ *6

0 FIX

1 FIX

0 FIX

0 FIX *7

1 FIX *3

0(DISABLE)/1(ENABLE)

0 FOR1 AV/1 FOR 2AV

0(DISABLE)/1(ENABLE)

1 FIX *3

0 FIX

0(DISABLE)/1(ENABLE)

0 ADJ *8

1 FIX

0 FIX

1 FIX

0(DISABLE)/1(ENABLE)

EEPROM ITEMS OSD

VERTICAL SCAN DISABLE VSD

EVG

BLACK STRETCH BKS

AUTOMATIC VOLUME LEVELING AVL

FAST FILTER IF-PLL FFI

ENABLE VERTICAL GU ARD (RGB BLANKING)

EHT TRACKING MODE (HCO) EHT

OVERSCAN SWITCH OFF OSO

VMC

BTSC

IF 2 AV-OUT, SET ‘1’

*1: UNLESS CUSTOMER REQUEST, OR ELSE FIX THE ADJUSTMENT.

*2: CDL DATA=2 , FOR 20” & 21” ONLY

*3: MANUAL CHANGE TO ‘0’

*4: MANUAL CHANGE TO ‘0’

*5: MANUAL CHANGE TO ‘0’

*6: IF 1 AV-OUT, SET TO ‘0’

*7: MANUAL CHANGE TO ‘1’

*8: IF BILINGUAL MODEL PLEASE CHANGE TO ‘1’

AUTO COLOUR LIMIT ACL

FORCED COLOUR LIMIT FCO

SOUND SYSTEM M S-M

SOUND SYSTEM DK S-DK

SOUND SYSTEM I S-I

SOUND SYSTEM BG S-BG

PLAYBACK SECAM P-SECAM

FE (RF) NTSC 3.58 F-N358

FE (RF) NTSC 4.43 F-N443

FE (RF) SECAM F-SECAM

VIDEO MUTE AT IDENT LOSS VMI

VIDEO MUTE AT PROGRAM/SOURCE CHANGE

HOTEL MODE HTL

REDUCED FM DEMODULATOR GAIN FOR BTSC SIGNAL

NUMBER OF EXTERNAL AV SOURCE AV

FM WINDOW SELECTION FMWS

SOUND MUTE BIT 0 SM0

SOUND MUTE BIT 1 SM1

THAI LANGUAGE THA

ARABIC LANGUAGE ARA

MALAY LANGUAGE MAL

CHINESE LANGUAGE CHI

FRENCH LANGUAGE FRE

RUSSIAN LANGUAGE RUS

FORCED V-SYNC SLICING LEVEL FSL

SYNC OF OSD HP2

TUNER CPT CPT

BILINGUAL BIL

IF AGC SPEED BIT 0 AGC0

IF AGC SPEED BIT 1 AGC1

PHI-1 TIME CONSTANT (RF) FOA-FE

PHI-1 TIME CONSTANT (RF) FOB-FE

PHI-1 TIME CONSTANT (OFF AIR) FOA-AV

PHI-1 TIME CONSTANT (OFF AIR) FOB-AV

NOTE :

FIXED DATA, PLEASE DO NOT CHANGE WITHOUT SPECIFIC INSTRUCTION.

FIX/ADJ REMARK

255 FIX

00H: 55H 02H: 43H

01H: 4FH 03H: A1H

ADDRESS DATA ADDRESS DATA

AFTER SHORT JA 122 & JA 124, AND TURN ON THE MAIN POWER SWITCH, READ

DA TA

FROM EEPROM ADDRESS 00H ~ 03H, AND COMPARE TO THE LIST BELOW, IF

DIFFERENT, INITIALIZE THE EEPROM.

DATA LENGTH INITIAL DATA

EEPROM ITEMS OSD

AGC TAKE OVER POINT AGC 0~63 14 ADJ

VERTICAL SLOPE V-LIN 0~63 32 ADJ

VERTICAL AMPLITUDE V-AMP 0~63 32 ADJ

VERTICAL SHIFT V-CENT 0~63 32 ADJ

HORIZONTAL SHIFT H-CENT 0~63 32 ADJ

S-CORRECTION S-COR 0~63 0 FIX

WHITE POINT RED STD WHITE TEMP DRI-RS 0~63 32 FIX

WHITE POINT GREEN STD WHITE TEMP DRI-GS 0~63 32 ADJ

WHITE POINT BLUE STD WHITE TEMP DRI-BS 0~63 32 ADJ

WHITE POINT RED WARM WHITE TEMP DRI-RW 0~63 32 FIX

0~99 OR>99FOR NONE

WHITE POINT GREEN WARM WHITE TEMP DRI-GW 0~63 32 FIX (DRI-GS)-7 DATA

WHITE POINT BLUE WARM WHITE TEMP DRI-BW 0~63 32 FIX (DRI-BS)-7 DATA

WHITE POINT RED COOL WHITE TEMP DRI-RC 0~63 25 FIX (DRI-BS)-7 DATA

WHITE POINT GREEN COOL WHITE TEMP DRI-GC 0~63 32 FIX (DRI-GS)-7 DATA

WHITE POINT BLUE COOL WHITE TEMP DRI-BC 0~63 32 FIX (DRI-BS) SAME DATA

MAX VOLUME SUB-VOL 0~63 63 FIX

SUB CONTRAST SUB-CON 0~63 63 FIX

SUB COLOUR SUB-COL 0~63 32 ADJ

SUB BRIGHTNESS SUB-BRI 0~63 32 ADJ

SUB TINT SUB-TINT 0~63 32 ADJ

SUB SHARPNESS SUB-SHP 0~63 32 FIX

MAX HOTEL VOLUME HTL-VOL 0~63 32 FIX *1

HOTEL PROGRAM NUMBER HTL-PRG

OSD GRB REFERENCE RGB 0~15 15 FIX

BLACK LEVEL OFF-SET R CUT-R 0~15 8 FIX

BLACK LEVEL OFF-SET B CUT-G 0~15 8 FIX

CATHODE DRIVE LEVEL CDL 0~15 0 FIX *2

Y-DELAY TIME FOR PAL(TV) [YD] DL-PT 0~15 12 FIX

Y-DELAY TIME FOR SECAM(TV) [YD] DL-ST 0~15 15 FIX

Y-DELAY TIME FOR N358 (TV) [YD] DL-3T 0~15 12 FIX

Y-DELAY TIME FOR N443 (TV) [YD] DL-4T 0~15 12 FIX

Y-DELAY TIME FOR B/W (TV) [YD] DL-TV 0~15 12 FIX

Y-DELAY TIME FOR PAL (AV) [YD] DL-PA 0~15 12 FIX

Y-DELAY TIME FOR SECAM (AV) [YD] DL-SA 0~15 15 FIX

Y-DELAY TIME FOR N358 (AV) [YD] DL-3A 0~15 12 FIX

Y-DELAY TIME FOR N443 (AV) [YD] DL-4A 0~15 12 FIX

Y-DELAY TIME FOR B/W (AV) [YD] DL-AV 0~15 12 FIX

COLOUR OFFSET (PAL) COL-OP 0~15 8 FIX

COLOUR OFFSET (SECAM) COL-OS 0~15 8 FIX

COLOUR OFFSET (NTSC358) COL-O3 0~15 4 FIX

COLOUR OFFSET (NTSC443) COL-O4 0~15 4 FIX

SHARPNESS OFFSET (PAL) SHP-OP 0~15 8 FIX

SHARPNESS OFFSET (SECAM) SHP-OS 0~15 4 FIX

SHARPNESS OFFSET (NTSC358) SHP-O3 0~15 12 FIX

SHARPNESS OFFSET (NTSC443) SHP-O4 0~15 8 FIX

20GT-15

PIF ADJUSTMENT CHECKING

ADJUSTMENT POINT

ADJUSTMENT CONDITION / PROCEDURE WAVEFORM OR OTHERS

Fig. 1

Fig. 2

Fig. 3-1

OSCILLOSCOPE

BIAS BOX

TV SET

Bias Box : about 4.5V

TP201

0.1V

E-9 CH

P C

-1.5+/-0.8dB

10k

100k

1n60

75ohm

IF OUT

1000p

Oscilloscope

Tuner IFT

( PRESET )

(1) Get the tuner ready to receive the CH. E - 9

signal, but with no signal input. Adjust the PLL

data.

(2) Connect the sweep generator's output cable to

the tuner antenna. (RF SWEEP)

(3) Adjust the sweep generator's to 80dBuV.

(4) Connect the response lead (use LOW

IMPEDANCE probe with wave detector ; see

Fig.1) to the tuner's IF output terminal.

(This terminal must have the probe alone

connected ).

(5) Set the RF AGC to 0 - 6 V with no saturation

with the waveform.

(6) Adjust the tuner IF coil to obtain the waveform

as shown in Fig. 2.

Note : Be sure to keep the tuner cover in position

during this adjustment.

2 RF-AGC

TAKE OVER

POINT

ADJUSTMENT

(I2C BUS

CONTROL)

(1) Receive "PAL COLOR BAR" signal. Signal

Strength: 57 ± 1dBµV (75 ohm open)

(2) Connect the oscilloscope to TP201 (Tuner's

AGC Terminal) as shown in Fig 3-1.

(3) Call "AG" mode in service mode. Adjust the

"AG" bus data to obtain the Tuner output pin

drop 0.1V below maximum voltage.

(4) Change the antenna input signal to 63 ~

67dBµV, and make sure there is no noise.

(5) Turn up the input signal to 90 ~ 95 dBµB to be

sure that there is no cross modulation beat.

Note : For the 50 ohm signal

strength gauge, when not

using 50/75 impedance

adapter, signal strength is

52 ± 1dBµV (75 ohm

open), instead of 57 ±

1dBµV (75 ohm open).

Precaution : The loss of using

impedance adapter.

–

SHIPPING SETTING & CHECKING

ITEMS DATA SETTING

LAST PROGRAM/CHANNEL 1

FLASHBACK PROGARM/CH 1

DIGIT 1

C-SYSTEM AUTO

S-SYSTEM *1 B/G

SKIP OFF

AFC ON

VOLUME 1

CONTRAST 60 (MAX)

COLOUR 0 (CENTER)

(1) The following default data has been factory-set for the E2PROM.

BRIGHTNESS 0 (CENTER)

TINT 0 (CENTER)

SHARPNESS 0 (CENTER)

WHITE TEMP ST AND ARD

REMINDER TIMER In-active, ”—:—”

ON TIMER In-active, ”—:—”

OFF TIMER In-activ e, ”—:—”

LAST POWER POWER-ON

LANGUAGE *1 THAI

BLUE BACK MUTE OFF

HOTEL MODE OFF

*1: PLEASE CHANGE IT BY REMOTE CONTROL

20GT-15

PURITY ADJUSTMENT

ADJUSTMENT POINT

ADJUSTMENT CONDITION / PROCEDURE WAVEFORM OR OTHERS

PURITY ADJ. (1) Receive the GREEN -ONLY signal. Adjust the

beam current to ~700µA (21"&20")/

~500µA(14").

(2) Maintain the purity magnet at the zero

magnetic field and keep the static convergence

roughly adjusted.

(3) Observe the points a, b, as shown in Fig. 1-1

through the microscope. Adjust the landings to

A rank requirement.

(4) Orient the raster rotation to 0 eastward.

(5) Tighten up the deflection coil screws.

Tightening torque : 108N ± 20N (11Kgf ± 2Kgf)

(6) Make sure the CRT corners landing meet the

A rank requirements. If not, stick the magnet

sheet to correct it.

Note : This adjustment must be done after

warming up the unit for 30 minutes or longer

with a beam current over 700µA.

(For 14", the beam current should be over

500µA).

Fig. 1-1

Fig. 1-2 Rank A (On the right of CRT)

Fig. 1-3 Rank A (On the left of CRT)

A=B

CONVERGENCE ADJUSTMENT

ADJUSTMENT POINT

ADJUSTMENT CONDITION / PROCEDURE WAVEFORM OR OTHERS

CONVERGENC

ADJ (To be

done after the

purity

adjustment.

(1) Receive the "Crosshatch Pattern" signal.

(2) Using the remote controller, call NORMAL

mode.

(Static convergence)

(1) Turn the 4 - pole magnet to a proper opening

angle in order to superpose the blue and red

colours.

(2) Turn the 6 - pole magnet to a proper opening

angle in order to superpose the green colour

over the blue and red colours.

(Dynamic convergence )

(1) Adjust the convergence on the fringes of the

screen in the following steps.

a) Fig. a :

Drive the wedge at point " a " and swing

the deflection coil upward.

b) Fig. b :

Drive the wedge at point " b " and " c " and

swing the deflection coil downward.

c) Fig. c :

Drive the " c " wedge deeper and

swing the deflection coil rightward.

d) Fig. d :

Drive the " b " wedge deeper and swing the

deflection coil leftward.

(2) Fix all the wedges on the CRT and apply glass

tape over them.

(3) Apply lacquer to the deflection yoke lock

screw, magnet unit (purity, 4 - pole, 6 - pole

magnets) and magnet unit lock screw.

Finally received the Red - only and Blue - only

signals to make sure there is no other colours

on the screen.

Fig. a

Fig. b

Fig. c

Fig. d

R G B

CRT NECK

Lacquer

Purity Magnet

4-Pole Magnet

6-Pole Magnet.

20cm

40cm (14")

(21")

B G R

R G B

B G R

R G B

Wedge "a"

Wedge "b"

Wedge "c"

About

100 Deg

About

100 Deg

Lacquer

20GT-15

HORIZONTAL, VERTICAL, DEFLECTION LOOP and

FOCUS ADJUSTMENT

ADJUSTMENT POINT

ADJUSTMENT CONDITION / PROCEDURE WAVEFORM OR OTHERS

V-SLOPE

(I2C BUS

CONTROL)

(1) Receive PAL 50Hz Monoscope Pattern Signal

(2) Call the "V-LIN" mode.

(3) Increase or decrease "V-LIN" by Volume key

till the horizontal line in the center of

monoscope is just at the position where the

blanking starts.

2 V-SHIFT

(I2C BUS

CONTROL)

(1) Call the "V-CENT" mode.

(2) Increase or decrease "V-CENT" by Volume

key till the picture is centered.

3 V - AMP

(I2C BUS

CONTROL)

(1) Call the "V-AMP" mode.

(2) Increase or decrease "V - AMP" by Volume

key to set overscan of 8.5% typical.

Adjustment Spec 8.5% range +1% -0%.

S-CORRECTION

(I2C BUS

CONTROL)

FIXED DATA, NO NEED TO ADJUST.

5 H- SHIFT (50)

(H - CENTER)

(I2C BUS

CONTROL)

(1) Call the "H-CENT" mode.

(2) Increase or decrease "H-CENT" by Volume

key to center the picture horizontal.

1 Focus (1) Receive the "Monoscope Pattern" signal.

(2) Press R/C to set Picture NORMAL condition.

(3) Adjust the focus control to get the best

focusing.

CUT OFF, BKGD, SUB-CONT ADJUSTMENT.

ADJUSTMENT POINT

ADJUSTMENT CONDITION / PROCEDURE WAVEFORM OR OTHERS

CRT CUTOFF

ADJUSTMENT

(I2C BUS

CONTROL)

(1) Switch TV to VIDEO mode, BLUE BACK

OFF, with NO VIDEO signal.

(2) Press R/C to set Picture Normal condition.

(3) Connect the oscilloscope to Red OUT from

IC801. (TP851)

Range : 1 V/Div (DC)

Sweep : 5 msec/Div

(3) Adjust SCREEN VR, so that the tip of signal

reach 3.0 Vdc ± 0.1 Vdc.

SUB-BRIGHTNESS

ADJUSMENT

(I2C BUS

CONTROL)

(1) Call "SUB-BRI" in service mode. (Receive

Crosshatch pattern with 5 black level

windows)

(2) Adjust the "SUB BRIGHT" bus data in order

that the line 1, 2 and 3 have the same

darkness wherelse line 4 is slightly brighter

than line 1, 2 and 3 and finally line 5 will be the

brighter than line 4.

WHITE

BALANCE

SERVICE

MODE ADJ

(I2C BUS

CONTROL)

(1) Receive the "WHITE" Pattern with BURST

signal.

(2) Press R/C to set Picture NORMAL condition.

(3) Connect the DC miliammeter between the

TP602 ( - ) TP 603 ( + ).

(4) Check Beam current should be around

1100µA. (20"/21") (14" around 800µA).

(5) Set it to service mode and adjust the DRI-GS,

DRI-BS data to have a colour temperature of

12,300°K . * Note .

(6) Receive "WHITE" pattern, WITH BURST

signal, and set Brightness Y by generator, to

** 10 cd/m2 (Minolta CA-100) by reducing

Luminate Y signal.

(7) Adjust "CUT-R" & "CUT-G" to get 12,300°K.

Then go back normal mode (High Bright**) to

check colour temperature. If out of range, back

to (1).

Note : This adjustment must be done after

warming up the unit for 30 minutes or

longer with a beam current over 700µA.

(For 14", the beam current should be over

500µA).

* ADJUST DRI-GC/GW, DRI-BC/BW AS

FOLLOWING DATA AFTER FINISHING DRI-GS

AND DRI-BS.

DRI-GC/GW DATA = "DRI-GS"-7 DATA

DRI-RC = 25; DRI-BC = DRI-BS;

DRI-RW = 32

DRI-BW DATA = "DRI-BS" -7 DATA

Max Beam

Check

(1) Receive the "Monoscope Pattern" signal.

(2) Press R/C to set Picture NORMAL condition.

(3) Connect the DC miliammeter between TP603

( + ) & TP 602 ( - )

(Full Scale: 3mA Range)

(4)

Beam current must be within 1100 ± 100µA (21")

800 ± 100µA (14")

Refer to SHIPPING SETTING &

CHECKING.

# 12300°K X : 0.272

Y : 0.275

(MINOLTA COLOUR ANALYZER

CA-100)

*Note: Above Data can be

UP/DOWN by Volume

key.

Low High

14" 10cd/m2 200cd/m2

20"/21" 10cd/m2 120cd/m2

1 2 3 4 5

3.0Vdc

1, 2, 3 are in same black level.

PAL CHROMA ADJUSTMENT

ADJUSTMENT POINT

ADJUSTMENT CONDITION / PROCEDURE WAVEFORM OR OTHERS

SUB COLOUR

(I2C BUS

CONTROL)

(1) Receive the "PAL Colour Bar" signal.

(2) Press R/C to set Picture Normal condition.

(3) Connect the oscilloscope to Red cathode.

(TP854)

Range : 20 V/Div (AC)

(Using 10:1 Probe)

Sweep Time : 10 µsec/Div

(4) Using the R/C call "SUB COL" in SERVICE

mode. Adjust SUB COLOUR bus data, so

that the 75% White & Red portions of PAL

Color Bar be at the same level shown as

Fig. 1-1.

(5) Clear the SERVICE mode.

Fig. 1-1

Cy G B

W Y 100% W Mg R

75%

20GT-15

NTSC CHROMA ADJUSTMENT

ADJUSTMENT POINT

ADJUSTMENT CONDITION / PROCEDURE WAVEFORM OR OTHERS

SUB-TINT

(I2C BUS

CONTROL)

(1) Receive the "NTSC 3.58 Color Bar" signal

thru AV in.

(2) Connect the oscilloscope to TP853 (P882 pin5)

BLUE-OUT.

Range : 1V/Div (AC) (Use Probe 10:1)

Sweep time : 10µsec/Div

(3) Call the "SUB-TINT" mode in service mode.

Adjust the "SUB-TINT" bus data to obtain the

waveform shown as Fig. 1-1.

(4) Clear the SERVICE mode.

Fig. 1-1

(B-Y)

SAME LEVEL

W Y Cy G Mg R B

PROTECTOR OPERATION CHECKING

ADJUSTMENT POINT

ADJUSTMENT CONDITION / PROCEDURE WAVEFORM OR OTHERS

BEAM

PROTECTOR

(1) Receive "Monoscope Pattern" signal.

(2) Set CONTRAST MAX.

(3) Set BRIGHT MAX.

(4) During the Collector & Emitter of Q883/5/7

short, make sure the protector ON and switch

to standby mode.

* Select one of Q883/5/7 to do

each short test.

H, V

PROTECTOR

(1) Receive "Monoscope Pattern" signal.

(2) Connect output of Bias Box to D607 cathode

(R606 side).

(3) Set voltage of Bias Box to 18V and make

sure the protector is not work.

(4) Set voltage of Bias Box to 27V, and make

sure the protector functions.

OTHER

PROTECTOR

(1) Once finish rectified Electrolytic Capacitor

short testing in + B line, check all possible

damaged components on +B line.

(Use random selected set for inspection)

A/V INPUT AND OUTPUT CHECKING

ADJUSTMENT POINT

ADJUSTMENT CONDITION / PROCEDURE WAVEFORM OR OTHERS

VIDEO AND

AUDIO

OUTPUT

CHECK

(1) Receive the "PAL Color Bar" signal (100%

White Color Bar, Sound 400 Hz 100% Mod).

(2) Terminate the Video output with a 75 ohm

impedance. Make sure the output is as

specified (1.0 Vp-p ± 3 dB)

(3) Terminate the Audio output with a 10 Kohm

impedance. Make sure the O/P is as specified

(1.76 Vp-p ± 3 dB)

VIDEO AND

AUDIO INPUT

CHECK

(1) Using the TV/AV key on the remote controller,

make sure that the modes change in order of

TV, AV1, AV2 & TV again and the video &

audio output are according to the input

terminal for each mode.

FUNCTION OPERATION CHECKING (1) (VIDEO & AUDIO)

ADJUSTMENT POINT

ADJUSTMENT CONDITION / PROCEDURE WAVEFORM OR OTHERS

CONTRAST

Key

(1) Receive "Monoscope Pattern" signal.

(2) Set P-Mode to select CONTRAST.

(3) Press Volume Up/Down key to check whether

the CONTRAST effect is OK or not.

COLOUR Key (1) Receive "Color Bar" signal.

(2) Set P-Mode to select COLOUR.

(3) Press Volume Up/Down key to check whether

the COLOUR effect is OK or not.

BRIGHTNESS

Key

(1) Receive "Monoscope Pattern" signal.

(2) Set P-Mode to select BRIGHTNESS.

(3) Press Volume Up/Down key to check whether

the BRIGHTNESS effect is OK or not.

TINT Key (1) Receive the "NTSC Colour Bar" signal thru AV

in.

(2) Set P-Mode to select TINT.

(3) Press Volume Up/Down key to check TINT,

UP for GREEN direction and DOWN for

PURPLE direction whether is OK or not.

SHARPNESS

Key

(1) Receive "Monoscope Pattern" signal.

(2) Set P-mode to select SHARPNESS.

(3) Press Volume Up/Down key to check whether

the SHARPNESS effect is OK or not.

CH DISPLAY

COLOUR

(1) All Ch (1~99) will have an OSD display of the

channel number in green colour under AFT

ON condition.

NORMAL Key (1) Once in PICTURE Mode, and the NORMAL

key is pressed, all the settings will be present

to normal setting.

(Normal setting value for every mode).

CONTRAST : MAX

COLOUR : CENTER

BRIGHTNESS : CENTER

TINT : CENTER

SHARPNESS : CENTER

WHITE TEMP (1) Receive "Monoscope Pattern" signal.

(2) Set FUNCTION to select WHITE TEMP.

(3) Press Volume Up/Down key to check WHITE

TEMP Option, STANDARD: NORMAL

SETTING, WARM for more REDDISH

direction changing, COOL for more BLUISH

direction changing.

COLOUR

SYSTEM

(1) Receive the "PAL COLOUR BAR" signal,

press the COLOUR SYSTEM key to select

modes except PAL, check the COLOUR is not

working properly. Then, select the "PAL" mode.

Check again its colour so that it is working

properly.

(2) Receive "NTSC 4.43/3.58 COLOUR BAR"

signal thru AV, press COLOUR SYSTEM key

to select modes except N4.43/3.58, check the

COLOUR is not working properly. Then, select

the "NTSC 4.43/3.58" mode. Check again its

colour so that it is working properly.

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