Panasonic TC-14A04P, TC-20A04P, TC-20B04 Service Manual

Order DCS - JUN2004 - 004 - MS

Service Manual

GP3 CHASSIS

TC-14A04P
TC-20A04P
TC-20B04

Color Television

Specifications

ITEM

Power source

Consumption
Antenna input jack
Color systems
Tuning system
Channel capability

Picture tube (Diagonal Visual)
Audio output
Video input jack
Video Outlet
Dimension (width, height, depth)
Weight

MODEL

TC-14A04P

1 10/220 V AC

50/60 Hz automatic switch

51 W

75 ohms - VHF/UHF/CATV

PAL-M/NTSC/PAL-N

F.S.T.

2 to 13 (VHF)
14 to 69 (UHF)
1 to125 (CATV)

Panablack 33 cm

3 W RMS

1 AV (rear)

1 (back)

370 x 351 x 366 mm

9,6 kg

TC-20A04P

1 10/220 V AC

50/60 Hz automatic switch

61 W

75 ohms - VHF/UHF/CATV

PAL-M/NTSC/PAL-N

F.S.T.

2 to 13 (VHF)
14 to 69 (UHF)
1 to125 (CATV)

Panablack 48cm

3 W RMS

1AV (rear)

1 (back)

502 x 455 x 471 mm

17 kg

TC-20B04

1 10/220 V AC

50/60 Hz automatic switch

61 W

75 ohms - VHF/UHF/CATV

PAL-M/NTSC/PAL-N

F.S.T.

2 to 13 (VHF)
14 to 69 (UHF)
1 to125 (CATV)

Panablack 48cm

3 W RMS

1 (front) 1(rear)

1 (back)

502 x 455 x 471 mm

17 kg

Specifications are subject to change without notice. Weight and dimensions shown are approximate.

Supplied Accessories:

• 1 Remote Control Transmitter

• 1 300Ω/75Ω Balum

• 2 “AA” (or R6) batteries (1.5V; ABNT/IEC)

• 1 Internal antenna (TC-14A04A and TC-20B04)

Panasonic

®

© 2004 Panasonic da Amazônia S/A.
CS Division
Technical Support

TC-14A04P / TC-20A04P / TC-20B04

Important Safety Notice

Special components are used in this television set which are important for safety. These parts are identified on the schematic
diagram by the symbol . It is essential that these critical parts are replaced with the manufacturers specified replacement
parts to prevent X-ray radiation, shock, fire or other hazards. Do not modify the original design without manufacturers permission.



Contents

OPERATING INSTRUCTIONS ................................................................ 4

IC601 - PINOUT ................................................................................... 5

IC VOLTAGE T ABLES .......................................................................... 6

IC601 - BLOCK DIAGRAM ................................................................... 7

GP3 CHASSI FEATURE SUMMAR Y ..................................................... 8

THE DAC CONTROL FUNCTIONS FOR THE GP3 CHASSIS ................... 9

SERVICE MODE:

HOW TO ENTER IN THE SERVICE MODE ................................................. 9

TO EXIT SERVICE MODE AND RETURN TO NORMAL MODE ................... 9

ADJUSTMENTS:

CHK1, CHK2, CHK3 and CHK4 ADJUSTMENTS OPTIONS ............... 9, 10

1- VIF DETECTOR OUTPUT LEVEL CONFIRMATION ......................... 1 1

3- BUZZING CONFIRMATION (AUDIO CIRCUIT) ................................ 1 1

4- ANODE AND HEA TER VOL T AGE CONFIRMA TION ........................ 11

5- P AL COLOR OUTPUT LEVEL ADJUSTMENT ................................ 12

6- NTSC SUB-TINT CALIBRA TION ..................................................... 12

7- PROTECTION CIRCUIT (SHUTDOWN) OPERATION) ...................... 12

8- SUB-BRIGHTNESS AND SUB-CONTRAST CALIBRA TION ............. 13

9- FOCUS CALIBRA TION ................................................................... 13

10- COLOR PURITY ADJUSTMENT ...................................................... 13

11- WHITE QUALITY CALIBRA TION ..................................................... 14

12- CONVERGENCE CALIBRATION ...................................................... 14

14- CRT CUT OFF CALIBRATION ....................................................... 14

15- VERTICAL DEFLECTION CALIBRA TION ........................................ 15

16- WITHE BALANCE CALIBRA TION ................................................... 15

EEPROM MEMORY MAPS ................................................................... 16

SCHEMA TICS DIAGRAMS:

CRT PCB SCHEMA TIC DIAGRAM ........................................................ 18

MAIN PCB SCHEMATIC DIAGRAM ...................................................... 19

MAIN PCB LAYOUT ............................................................................ 20

SIGNAL WA VEFORMS ........................................................................ 21

EXPLODED VIEW ................................................................................. 25

General Guidelines

An Isolation Transformer should always be used during the servicing
of a receiver whose chassis is not isolated from the AC power line. Use
a transformer of adequate power rating as this protects the technician
from accidents resulting in personal injury from electrical shocks. It will
also protect the Receiver from being damaged by accidental shorting
that may occur during servicing.
When servicing, observe the original lead dress, especially in the high
voltage circuit. Replace all damaged parts (also parts that show signs
of overheating.)
Always Replace Protective Devices, such as fishpaper, isolation
resistors and capacitors, and shields after servicing the Receiver.
Use only manufacturers recommended rating for fuses, circuit
breakers, etc.
High potentials are present when this Receiver is operating. Operation
of the Receiver without the rear cover introduces danger from electrical
shock. Servicing should not be performed by anyone who is not
thoroughly familiar with the necessary precautions when servicing high­voltage equipment.
Extreme care should be practiced when Handling the Picture Tube.
Rough handling may cause it to implode due to atmospheric pressure
(14.7 lbs per sq. in). Do not sick or scratch the glass or subject it to any
undue pressure. When handling, use safety goggles and heavy gloves
for protection. Discharge the picture tube by shorting the anode to
chassis ground (not to the cabinet or to other mounting hardware).
When discharging, connect cold ground (i.e. dag ground lead) to the
anode with a well insulated wire or use a grounding probe.
Avoid prolonged exposure at close range to unshielded areas of the
picture tube to prevent exposure to X-ray radiation.
The Test Picture Tube used for servicing the chassis at the bench
should incorporate safety glass and magnetic shielding. The safety
glass provides shielding for the tube viewing area against X-ray radiation
as well as implosion. The magnetic shield limits X-ray radiation around
the bell of the picture tube in addition to restricting magnetic effects.
When using a picture tube test jig for service, ensure that the jig is
capable of handling 31kV without causing X-ray radiation.
Before returning a serviced receiver to the owner, the service technician
must thoroughly test the unit to ensure that is completely safe to operate.
Do not use a line isolation transformer when testing.

PARTS LISTS:

REPLACEMENT MECHANICAL P ARTS LIST ........................................ 26

REPLACEMENT ELECTRICAL PA RTS LIST .......................................... 27

- 2 -



Warning !

It is essential that these critical parts are replaced
with the manufacturers specified replacement parts
to prevent X-ray radiation, shock, fire or other haz­ards.

ABOUT LEAD FREE SOLDER (PbF)

This model uses lead free solder (PbF).

CAUTION:

TC-14A04P / TC-20A04P / TC-20B04

• Pb free solder has a higher melting point than standard solder; typically the melting point is
50 - 70°F (300 - 400°C) higher. Please use a high temperature soldering iron. In case of the
soldering iron with temperature control,please set it to 700 ± 20°F (370 ± 10°C).

• Pb free solder will tend to splash when heated too high (about 1 100°F/ 600°C).
When soldering or unsoldering, please completely remove all of the solder on the pins or
solder area, and be sure to heat the soldering points with the Pb free solder until it melts
enough.

- 3 -

TC-14A04P / TC-20A04P / TC-20B04

OPERATING INSTRUCTIONS

input jack

Audio/video

Back view

Front view

Panasonic

cord output

Power supply

Antenna

input jack

Location of Controls (TC-14A04P / TC-20A04P)

CHANNEL

OLUME

PRE. TV/AV V

u

ER

POW

button

TV/AV

button

PRESET

Remote

control sensor

Power switch

Indication light

Front view Back view

AUDIO

AV IN

VIDEO

Panasonic

V

V

+

-

TV/AV

PRE.

POWER

Power cable

ENTRADA

VIDEO

AUDIO

input jack

Audio/Video

Antenna

input jack

Indication light

VIDEO AUDIO

– +

PRE. TV/AV

POWER

AV/IN

Earphone output

Volume buttons

button

TV/AV

Remote

Power switch

Audio/Video input

(–) (+)

button

PRESET

control sensor

Location of Controls (TC-20B04)

- 4 -

TC-14A04P / TC-20A04P / TC-20B04

IC601 - PINOUT

Symbol Pin Description

P3.1/ADC1 1 port 3.1 or ADC1 input
P3.2/ADC2 2 port 3.2 or ADC2 input
P3.3/ADC3 3 port 3.3 or ADC3 input
VSSC/P 4 digital ground for m-Controller core and periphery
P0.5 5 port 0.5 (8 mA current sinking capability for direct drive of LEDs)
P0.6/CVBSTD 6 port 0.6 (8 mA current sinking capability for direct drive of LEDs) or Composite video input. A positive-going

1V (peak-to-peak) input is required
VSSA 7 digital ground of TV-processor
SECPLL 8 SECAM PLL decoupling
VP2 9 2nd supply voltage TV-processor (+8V)
DECDIG 10 supply voltage decoupling of digital circuit of TV-processor
PH2LF 11 phase-2 filter
PH1LF 12 phase-1 filter
GND3 13 ground 3 for TV-processor
DECBG 14 bandgap decoupling
EWD 15 East-West drive output
VDRB 16 vertical drive B output
VDRA 17 vertical drive A output
IFI N1 18 IF input 1
IFI N2 19 IF input 2
IREF 20 reference current input
VSC 21 vertical sawtooth capacitor
AGCOUT 22 tuner AGC output
SIFIN1 23 SIF input 1
SIFIN2 24 SIF input 2
GND2 25 ground 2 for TV processor
SNDPLL 26 narrow band PLL filter
AVL/REF0/SNDIF (1) 27 Automatic Volume Levelling / subcarrier reference output / sound IF input
AUDIO2 28 audio 2 input
AUDIO3 29 audio 3 input
HOUT 30 horizontal output
FBISO 31 flyback input/sandcastle output
DECSDEM 32 decoupling sound demodulator
QSSO/AMOUT/ 33 QSS intercarrier output / AM output in stereo applications or deemphasis
AUDEEM (1) (front-end audio out) / AM output in mono applications
EHTO 34 EHT/overvoltage protection input
PLLIF 35 IF-PLL loop filter
SIFAGC 36 AGC sound IF
INTCO 37 intercarrier output (from QSS or vision IF amplifier)
IFVO/SVO (1) 38 IF video output / selected CVBS output
VP1 39 main supply voltage TV processor
CVBS1 40 internal CVBS input
GND 41 ground for TV processor
CVBS2 42 external CVBS2 input
GND 43 ground for TV-processor
CVBS3/Y 44 CVBS3/Y input
C 45 chroma input
WHSTR 46 white stretch capacitor
CVBSO 47 CVBS output
AUDOUT /AMOUT 48 audio output /AM audio output (volume controlled)
SVM 49 scan velocity modulation output
INSSW2 50 2nd RGB / YUV insertion input
R2/VIN 51 2nd R input / V (R-Y) input / PR input
G2/YIN 52 2nd G input / Y input
B2/UIN 53 2nd B input / U (B-Y) input / PB input
BCLIN 54 beam current limiter input
BLKIN 55 black current input / V-guard input
RO 56 Red output
GO 57 Green output

- 5 -

TC-14A04P / TC-20A04P / TC-20B04

IC601 - PINOUT

Symbol Pin Description

BO 58 Blue output
VDDA 59 analog supply of Teletext decoder and digital supply of TV-processor (3.3 V)
VP E 60 OTP Programming Voltage
VDDC 61 digital supply to core (3.3 V)
OSCGND 62 oscillator ground supply
XTALIN 63 crystal oscillator input
XTALOUT 64 crystal oscillator output
RESET 65 reset
VDDP 66 digital supply to periphery (+3.3 V)
P1.0/INT1 67 port 1.0 or external interrupt 1 input
P1.1/T0 68 port 1.1 or Counter/Timer 0 input
P1.2/INT0 69 port 1.2 or external interrupt 0 input
P1.3/T1 70 port 1.3 or Counter/Timer 1 input
P1.6/SCL 71 port 1.6 or I2C-bus clock line
P1.7/SDA 72 port 1.7 or I2C-bus data line
P2.0/TPWM 73 port 2.0 or Tuning PWM output
P2.1/PWM0 74 port 2.1
P2.2/PWM1 75 port 2.2
P2.3/PWM2 76 port 2.3
P2.4/PWM3 77 port 2.4
P2.5/PWM4 78 port 2.5
SYNC_FILTER 79 CVBS (i.e. P0.6/CVBS) Sync filter input: This pin should be connected to VSSA via a 100 nF capacitor.
P3.0/ADC0 80 port 3.0 or ADC0 input

IC VOLTAGE TABLES

Pin Voltage

1 3,3
2 21.2mV
32
40
5 2,56
6 97.5mV
70
8 2,3
98
10 5
11 3,3
12 3,9
13 0
14 4
15 11.6mV
16 1,3
17 1,3
18 1,9
19 1,9
20 3,9
21 3,8
22 146.7mV
23 181.3mV
24 181.3mV
25 0
26 1,3
27 2,5
28 3,7
29 3,7
30 0,6
31 0,5
32 2,3
33 2,8
34 1,6
35 1,5
36 198mV
37 0,4
38 2,7
39 8
40 3,6

IC601

Pin Voltage

41 0
42 3,8
43 0
44 3,3
45 0
46 3,6
47 2,9
48 3,5
49 4,4
50 2,5
51 2,7
52 2,7
53 2,7
54 2
55 5,3
56 3
57 3
58 3
59 3,3
60 0
61 3,3
62 28.5mV
63 1,9
64 1,9
65 0
66 3,3
67 105mV
68 4,7
69 5
70 3,2
71 2,3
72 3
73 55.9mV
74 0
75 0
76 3,7
77 0
78 0
79 0
80 0

IC451

Pin Voltage

1 0,3V
2 15,6V
3 -14V
4 -15,6V
5 67mV
6 16,5V
7 0,3V

IC1103

Pin Voltage

1 7,3mV
2 7,3mV
3 7,3mV
4 7,3mV
5 3,8V
6 3,8V
7 0,2V
85V

IC801

Pin Voltage

1 183V
2
3 22,7V
4 22,3V
5 96mV
6 1,5V
7 0,52V

IC1201

Pin Voltage

15V
2 6,4mV
3 1,27V
4 3,3V
5 6,4mV
65V

IC851

Pin Voltage

1 10,5V
2 10,5V
3 6,5V
4 4,3mV
5 6,3V
68V
75V

IC2301

Pin Voltage

1 11,22V
2 0,26V
3 6,6mV
4 0,23V
5 0,2V
6 1,46V
7 6,6mV
8 0,25V
9 50mV

X101

Pin Voltage

1 0,25V
2 0,25V
3 1,9V
4 1,9V

IC802

Pin Voltage

1 141V
2 8,5V
3 -8,7mV

T801

Pin Voltage

(V2) 1 22,5mV
(V1) 2 23mV
(P2) 5 180V
(PT) 7 170V
(P1) 8 168V
(S6) 11 0,5V
(S1) 12 0,2V
(S2) 15 0,7V
(S3) 17 0,2V

TPA10 142V
TPA11 11,2V

Pin Voltage

1 10,4V
25V
3 -3,9mV

All voltage measurements were made in POWER ON mode, with 127V 60Hz power
source and Color Bars Video Pattern.

IC880

- 6 -

IC601 - BLOCK DIAGRAM

TC-14A04P / TC-20A04P / TC-20B04

+3.3 V

PWMS(4X)

I/O PORTS (4x)

ADC IN (4x)

VST OUT

SDASCL

LED OUT (2x)

VPE

RESET

AUDOUT

AUDIO3

AUDIO2

1/10 PAGE

MEMORY

C-BUS

2

I

TRANSCEIVER

VST PWM-DAC

80C51 CPU

ENHANCED

I/O PORTS

DISPLAY

TELETEXT/OSD

V

H

TELETEXT

ACQUISITION

CVBS

ROM/RAM

ROGOBO

BL

B

RG

CONTR/BRIGHTN

OSD/TEXT INSERT

COR

SYNC

DELAY LINE

BASE-BAND

BLKIN

BCLIN

GB

CCC

R

WHITE-P. ADJ.

BLUE STRETCH

TINT CONTROL

SATURATION

BLACK STRETCH

RGB/YUV INSERT

WHITE STRETCH

Y

U

V

EW GEOMETRY

V-DRIVE +

GEOMETRY

V

G/Y B/U BL

R/V

(EWD)

EHTO

VMOUT

HOUT V-DRIVE

(AVL)

(SNDIF)

AUDEEM

QSSO/AMOUT

AVL

SOUND PLL

DEEMPHASIS

AUDIO SWITCH

VOLUME CONTROL

AGC

QSS MIXER

QSS SOUND IF

AM DEMODULTOR

SIFIN

LUMA DELAY

REF

VISION IF

PLL DEMOD.

VIFIN

TUNERAGC

PEAKING

VMOUT

AGC/AFC

VIDEO AMP.

- 7 -

PAL/SECAM/NTSC

REF

VIDEO SWITCH

IFVO

TRAP

SOUND

DECODER

VIDEO IDENT.

VIDEO FILTERS

CVBS3/Y

CVBS2

C

CVBSO

Y

LOOP

nd

H-DRIVE

H-SHIFT

2

H

H-OSC. + PLL

H/V SYNC SEP.

+8V

TC-14A04P / TC-20A04P / TC-20B04

CHASSIS GP3 FEATURE SUMMARY

MODELS : TC-14A04P, TC-20A04P and TC-20B04
SYSTEM : 3 systems (P AL-M/P AL-N/NTSC) (P AL-M 50hZ)
POWER SOURCE : CA automatic power switching (1 10/220)V, 50/60Hz
MEMORY : 125 positions
TV TUNING RANGE : 181 channels (TV / CA TV)
OSD LANGUAGE : Portuguese, Spanish and English
AUDIO SYSTEM : Mono
VERTICAL MAGNETIC FIELD : -0.1 ±0.03
COLOR TEMPERATURE : (High Light) x= 0.275±0.01, y=0.284 ±0.01, Y=150 (nit))

(Low Light) x= 0.273±0.01, y=0.283 ±0.01, Y=7.0 (nit)

REFERENCE VOLTAGE

CONTENTS TEST POINT

+B VOLTAGE

Buzzing confirmation

PAL color output

NTSC color output

Anode (EHT) voltage

MODEL

TPA10

TPA8
TPA9

TPA21

A22-3

ou TPA41

TPL2
TPL1
TPL1

CRT ANODE

ADJUSTMENT POINTS

MEMORY DATA

DA TA

VOLTAGE

140 ± 1,5V

8 ±1V
5 ±1V

175 ±1V

0.5 Vp-p

D
C
C

2.45 ±0.1Vo-p

2.45 ±0.5Vo-p

1.2 ±0.5Vo-p

24.5 +0.7 (Kv)

24.5 -1.5 (kV)

TC-14A04A

TC-20A04A

[A]=C1H , [B]=00H , [C]=00H , [D]=33H , [E]=00H , [F]=20H , [G]=00H , [H]=01H
[A]=C1H , [B]=00H , [C]=00H , [D]=33H , [E]=00H , [F]=20H , [G]=00H , [H]=01H

- 8 -

TC-14A04P / TC-20A04P / TC-20B04

THE DAC CONTROL FOR GP3 CHASSIS FUNCTIONS AND ADJUSTMENTS

HOW TO ENTER IN THE SERVICE MODE:

1- Set the “OFF TIMER” to 30 minutes.
2- Press simultaneously RECALL key on the remote control and VOL(-) button on the unit.

After a couple of seconds, the expression “CHK” should appear on the right superior side of the screen. (T o change
the memory data, press MUTE and VOLUME(_) simultaneously while the OSD is still on CHK1 mode. Key “4” moves
forward in the memory , and key “3” moves back in the memory

Note: T o alter from CHK1 mode to CHK2, CHK3 or CHK4 modes, press key “2” to move forward and the key “1” to

move back, as illustrated below.

NORMAL MOD E

Turn off

OPTION CODE

CHK1

SETTING

“2”

“

1

”

SERVICE MODE

“2”“

CHK2 CHK3 CHK 4

VCJ

ADJUSTMENT

PINCUSHION

ADJUSTMENT

1

”“

“

TO EXIT SERVICE MODE AND RETURN TO NORMAL MODE:

Press the “NORMAL” key on the remote control unit or turn off the TV.

CHK1 - OPTIONS

On CHK1 mode, it is possible to adjust the options below:

“4”

OPTION1 OPTION1 OPTION2 OPTION2

DIGITO MSB DIGITO LSB DIGITO M SB DIGI TO LSB

OPTION3

DIGITO MSB

OPTION5

DIGITO MSB

OPTION7

DIGITO MSB

ááá

“3”

“4”

á

OPTION3

á

DIGITO LSB

“3”

“4”

á

OPTION5

á

DIGITO LSB

“3”

“4”

á

OPTION8

á

DIGITO LSB

“3”

“4”

“3”

“4”

á

OPTION4

á

DIGITO MSB

“3”

“4”

á

OPTION6

á

DIGITO MSB

“3”

“4”

á

OPTION1

á

DIGITO MSB

“3”

“4”

“3”

“4”

á

OPTION4

á

DIGITO LSB

“3”

“4”

á

OPTION6

á

DIGITO LSB

“3”

“4”

å

“3”

“3”

“3”

“4”

“4”

“4”

“3”

å ááá

å

å

Note:

To select an option, type “4” to move forward
and “3” to move back.
After having selected the desired option, adjust
it by pressing the “VOL(_)” or “VOL(+)” keys.
Press “0” to memorize the adjustment.

2

”

WHITE BALANCE

ADJUSTMENT

1

”

CHK1 mode adjustments

On CHK1 mode it is possible to adjust the items of the table shown here.

Note:

T o select an item, type “4” to move forward and “3” to move back.
After having selected the desired option, adjust it by pressing the “VOL(_)” or “VOL(+)”
keys.
Press “0” T o memorize the adjustment.

- 9 -

CHK1 mode table

Standard values

OPTION1
OPTION2
OPTION3
OPTION4
OPTION5
OPTION6
OPTION7
OPTION8

14”

00
00
00
33
00
20
00
01

20”

00
00
00
33
00
20
00
01

TC-14A04P / TC-20A04P / TC-20B04

ADJUSTMENTS

CHK2 mode adjustments

On CHK2 mode it is possible to adjust the items of the table shown here.

Note:

T o select an item, type “4” to move forward and “3” to move back.
After having selected the desired option, adjust it by pressing the “VOL(_)” or “VOL(+)”
keys.
Press “0” T o memorize the adjustment.

CHK3 mode adjustments

On CHK3 mode it is possible to adjust the items of the table shown here.

Note:

T o select an item, type “4” to move forward and “3” to move back.
After having selected the desired option, adjust it by pressing the “VOL(_)” or “VOL(+)”
keys.
Press “0” T o memorize the adjustment.

CHK4 mode adjustments

On CHK4 mode it is possible to adjust the items of the table shown here.

Note:

T o select an item, type “4” to move forward and “3” to move back.
After having selected the desired option, adjust it by pressing the “VOL(_)” or “VOL(+)”
keys.
Press “0” T o memorize the adjustment.

CHK2 mode table

RF AGC
CONT
COL
S-COL
TINT
S-TINT
BRT

CHK3 mode table

Standard values

V-SLOPE 60HZ
V-SHIFT 60HZ
V-AMP 60HZ
H-SHIFT 60HZ
S-CORR 60HZ

CHK4 mode table

Standard values

R-CUT
G-CUT
BRT
S-BRT
CONT
S-CONT
R-DR
G-DR
B-DR
RGB CON

Standard values

14”

24

100

50
34
50
30
30

14”

35
36
44
18
28

14”

26
25
50
28

100

21
28
31
33

2

20”

24

100

50
34
50
30
30

20”

35
36
44
18
28

20”

26
25
50
28

100

21
28
31
33

2

ADJUSTMENTS

TEST AND MEASUREMENT EQUIPMENTS

T o execute all these electrical adjustments, the following equipment are required:

• Dual-Trace Oscilloscope
Voltage Range: 0.001 V to 50 V/Div.
Frequency Range: DC to 50 MHz
Probes: 10:1, 1:1

• NTSC Video Pattern Generator

• DVM (Digital V olt Meter)

• MTS/SAP Signal Generator

• (TV Multi-Channel Sound Modulator (U.S.A.))

• Plastic Tip Driver and Non-Metal Driver

• Isolation Transformer (V ariable)

• Degaussing Coil

• White Pattern Generator

• Audio Generator

- 10 -

ADJUSTMENTS

ITEM / PREPARATION PROCEDURE

TC-14A04P / TC-20A04P / TC-20B04

1- RF AGC ADJUSTMENT

1. Supply a color bar pattern and adjust the RF input signal
of 69 dB µV (75Ω opened channel 07 RF freq.: 175.25

MHz).

2. Connect the digital multimeter in TPA15.

2- VIF DETECTOR OUTPUT LEVEL

CONFIRMATION

3- BUZZING CONFIRMATION

(AUDIO CIRCUIT)

1. Connect the oscilloscope with a 7kHz filter between A22-

2 and A22-3 speakers terminals .

2. Adjust the sound to maximum.

3. Adjust AVL: OFF

ADJUSTMENT:

1. Select RF AGC on CHK2 service mode.

2. Adjust "RF AGC" by pressing VOL(+) or (-) until obtaining

2.2±0.1V in TPA15.

3. Increase the input level by +2 dB and confirm that the
voltage decreases in TPA15.

CONFIRMATION:

1. Install the chassis in the VIF calibration JIG and tune in a

63 dBU colorbar pattern (75Ω opened).

2. Connect the oscilloscope in TPA31.

3. Confirm that the output video sign is 1.05 ± 0.15 Vp-p in

TPA 31.

CONFIRMATION:

1. Supply a colorbar signal with local frequency adjusted

and the AFC ON (Channel with sound bearer and without
modulation).

2. Assure that the width in the buzzing waveform is smaller

than 500 m Vp-p.

4- ANODE AND HEATER VOLTAGE CONFIRMATION

1. Supply a crosshatch signal.

2. Adjust the current beam to zero. (0 beam).

3. Adjust “SCREEN VR” and “CONTRAST” to minimum.
Nota:

(When using a high voltage meter resistive type, it is
necessary to use an electrostatic meter type to verify the
values)

smaller than
500 m Vp-p

CONFIRMATION

1. Connect a voltage meter between TPA10 and ground.

Confirm that the voltage +B is within a range of 140.5V±

1.5V

2. Connect a high frequency voltage meter (VRMS) among

the heater, and confirm that the voltage is as below:

14" SAMSUNG A34KQW42X 6,30 ± 0,25 Vrms
14" PHILIPS A34EAK01X 6,15 ± 0,25 Vrms
20" SAMSUNG A48KRDB89X 6,30 ± 0,25 Vrms
20" PHILIPS A48EAK01X 6,15 ± 0,25 Vrms

3. Connect the high voltage meter in the CRT anode pin,

and confirm that the high voltage is within [A] range.

CRT [A]

14” 25,2 ~ 23,0
20” 27,2 ~ 25,0

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