Sharp 25WG3 Schematic

SERVICE MANUAL

SY8A725WG3///

COLOUR TELEVISION

Chassis No. SS-1

25WG3

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.

25WG3

CONTENTS

Page

• FEATURE ............................................................2

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

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

• ADJUSTMENT PRECAUTIONS ......................... 3

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

• SERVICE ADJUSTMENT ................................... 7

• TROUBLESHOOTING ...................................... 13

• SOLID STATE DEVICE BASE DIAGRAM ........ 14

• WAVEFORMS ...................................................15

• DESCRIPTION OF SCHEMATIC DIAGRAM.... 15

• BLOCK DIAGRAM .............................................16

• CHASSIS LAYOUT ............................................22

• SCHEMATIC DIAGRAM ................................... 24

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

• PARTS LIST ......................................................37

Page

W ARNING

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

25WG3

SPECIFICATIONS

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

FEATURE

Focus ...............................................................Bi-Potential, Uni-Potential Electrostatic

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

Intermediate Frequency

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

Sound IF Carrier ..............................................................................33.16/33.4 MHz

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

Power Input .................................................................... AC 110-240V, 50/60Hz (Auto)

Power Consumption ............................................................................................. 130W

Audio Power Output Rating ..................................................................7.5 W x 2(Max)

Speaker

Size ......................................................................................... 10 cm Round x 2pcs.

Voice Coil Impedance...................................................................... 8 ohm at 400 Hz

Aerial Input Impedance ................................................................. 75 ohm Unbalanced

Receiving Channels

PAL-B/G

VHF .......................................................... E2(44.25MHz) thru E12(463.25 MHz)

UHF..................................................... E21(471.25 MHz) thru E69(863.25 MHz)

Dimensions (Approx.)........................................574.0 (W) x 564.5 (H) x 499.0 (D) mm

Weight (Approx.) .................................................................................................. 28 kg

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

Specifications are subject to change without notice.

• PAL B/G, AV NTSC System

• Auto Search Tuning System

• 100-CH Program Memory

• AV Stereo sound

• High Contrast Picture (Black Stretch Circuit)

• CATV (Hyper Band) Ready<Used Frequency Synthesizer Tuner>

• 7 Mode Surround system

• Picture Signal Improvement Circuit

• 2 Language OSD

• On Timer/ Sleep Timer/ Reminder Timer

• Picture Noise Reduction Circuit

• Blue Back Noise Mute

• Front AV-In & Rear AV-In/Out Terminals

25WG3

C bus

ADJUSTMENT PRECAUTIONS

PROM is

C bus control)

put service mode. (Adjustment through the I

one by one.

data can be modified.

essor is put out of the service mode.

(1) Set the switch S1006 to the service mode position, and the microprocessor is

(2) Press the CH UP key on the remote controller to get ready to select the mode

(3) Press the CH DOWN key on the remote controller to select the modes re versely

(4) Using the VOLUME UP/ VOLUME DOWN key on the remote controller, the

(5) Set the switch S1006 to the normal mode (OFF) position, and the microproc-

switch. Initial values are automatically preset only when a new E

used (judgement with the first 4 bytes).

(1) Set the switch S1006 to the service mode position and turn on the main power

(2) The initial data are preset as listed in page 5~6.

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

FIRST TIME, make sure to set the switch S1006 to the service mode position

first and then turn on the main power switch (See 2-(1) above).

This model’s setting are adjusted in two different ways: through the I

control and in the conventional analog manner. The adjustments via the I

control include preset-only items and variable data.

1. Calling the service mode by the microprocessor.

2. Factory Presettings.

IMPORTANT

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

IMPORTANT SERVICE NOTES

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

fied service personnel only.

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.

SERVICING OF HIGH VOL TAGE SYSTEM AND PICTURE

TUBE

When servicing the high voltage system, remove static charge from it by con-

necting 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 cord should be

disconnected from AC outlet.)

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

X-RAY

than 32.0 kV (at beam 0µA) for the set.

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

minimum. Since certain malfunctions or servicing many produce potentially

hazardous radiation with prolonged exposure at close range, the f ollowing pre-

cautions should be observed:

1. When repairing the circuit, be sure not to increase the high voltage to more

2. To keep the set in a normal operation, be sure to make it function on 29.0 ±

1.5kV (at beam 1300µA) in the case of the set. The set has been factory-

may cause excess X-Ray radiation.

Adjusted to the above mentioned high voltage.

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

BEFORE RETURNING THE RECEIVER

Before returning the receiver to the user, perform the following safety

checks.

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

receiver.

fishpapers, cabinet backs, adjustment and compartment covers or

shields, isolation resistor- capacity networks, mechanical insulators etc.

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

2. Inspect all protective device such as non-metallic control knobs, insulating

25WG3

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

AKB/BKGD

MODE

50Hz ADJ

MODE

EAST-WEST

MODE

VERTICAL

MODE

NVM

MODE

60Hz ADJ

MODE

OPTION ADJ

MODE

AV/IGR

MODE

SUB ADJ

MODE

AGC/VCO

MODE

FORWARD: CH UP

REVERSE: CH DOWN

AKB/BKGD MODE

. WHITE POINT (G)

. WHITE POINT (B)

. AKB ON/OFF

KEY

WHITE-POINT(G)

WHITE-POINT(B)

AKB

2 KEY

3 KEY

8 KEY

DOWN

5 KEY

6 KEY

ON/OFF

In the direction of arrow: CH UP key

In the opposite direction : CH DOWN key

* The character in parentheses appear on the on-screen display.

50Hz ADJ MODE

V-SLOPE (V-SLOPE)

H-SHIFT 50Hz (H-SIFT50)

V-SHIFT 50Hz (V-SIFT50)

EAST-WEST ADJ MODE

WIDTH (WIDTH)

PARABORA/WIDTH (PARA)

CORNER PARABORA (CORNER)

TRAPEZIUM (TRAPE)

In the direction of arrow: CH UP key

In the opposite direction: CH DOWN key

* The character in parentheses appear on the on-screen display.

VERTICAL ADJ MODE

V-AMP (V-AMP)

S-CORRECTION

(S-COR)

SUB ADJ MODE

SUB CONTRAST

(SUB CON)

SUB COLOUR

(SUB COL)

SUB BRIGHTNESS

(SUB BRI)

SUB TINT (SUB TIN)

60Hz ADJ MODE

H-SHIFT 60 (H-SIFT60)

V-SHIFT 60 (V-SIFT60)

AV/IGR ADJ MODE

RF SUB VOLUME

(RF SUB VOL)

SP SUB VOLUME

(SP SUB VOL)

AV TINT (AV TINT)

AV SHARPNESS

(AV SHARP)

IGR BALANCE

(IGR LEVEL)

IGR SEPARATION

(IGR STEREO)

AGC/VCO ADJ MODE

AGC (AGC)

AUTO VCO (AUTO VCO)

MANUAL VCO (MANUAL VCO)

OPTION ADJ MODE

SECAM ON/OFF(SECAM)

M ON/OFF (M)

NICAM AUTO / I / B/G (NICAM)

PSI ON/OFF (PSI)

Y-DELAY (Y-DELAY)

PIP ON/OFF (PIP)

TUNER SHARP/MURATA(TUNER)

TEMP (TEMP)

LANGUAGE (LANG)

TDA7429 ON /OFF (TDA7429)

MONOBILIGUA ON/OFF(MONOBI)

AV2 ON/OFF (AV2)

S-SYSTEM (S-SYS)

C-SYSTEM (C-SYS)

FAVOURITE CH (FAVOURITE)

SERVICE MODE

25WG3

MCL1 (R/C CODE =117) MCL2 (R/C CODE=169)

PROM.

MCL1 & MCL2 CHANNEL SETTING

1). In service mode, After execute select POS 1, setting the following data in

PROM

1 48.25 AUTO 1 46.25 AUTO

2 62.25 AUTO 2 64.25 AUTO

3 77.25 AUTO 3 86.25 AUTO

CH-NO Fv (MHz) SOUND SYS CH-NO Fv (MHz) SOUND SYS

4 175.25 AUTO 4 95.25 AUTO

5 182.25 AUTO 5 138.25 AUTO

6 183.25 AUTO 6 175.25 AUTO

7 191.25 AUTO 7 182.25 AUTO

8 196.25 AUTO 8 189.25 AUTO

9 210.25 AUTO 9 196.25 AUTO

10 224.25 AUTO 10 209.25 AUTO

11 471.25 AUTO 11 216.25 AUTO

12 487.25 AUTO 12 SKIP OFF FREE

13 503.25 AUTO 13 SKIP OFF FREE

14 575.25 AUTO 14 SKIP OFF FREE

15 599.25 AUTO 15 SKIP OFF FREE

16 621.25 4.5 M 16 SKIP OFF FREE

17 639.25 AUTO 17 SKIP OFF FREE

18 703.25 AUTO 18 527.25 AUTO

19 735.25 AUTO 19 847.25 AUTO

20 767.25 AUTO 20 48.25 AUTO

21 815.25 AUTO 21 175.25 AUTO

22 855.25 AUTO 22 210.25 AUTO

23 855.25 AUTO 23 224.25 AUTO

24 55.25 4.5 M 24 575.25 AUTO

25 83.25 4.5 M 25 599.25 AUTO

26 183.25 4.5 M 26 767.25 AUTO

27 193.25 4.5 M 27 183.25 4.5 M

28 217.25 4.5 M 28 193.25 4.5 M

29 471.25 4.5 M 29 112.25 AUTO

30 477.25 4.5 M 30 168.25 AUTO

31 693.25 4.5 M 31 SKIP OFF FREE

32 SKIP OFF FREE 32 294.25 AUTO

33 112.25 AUTO 33 463.25 AUTO

34 169.25 AUTO 34 174.95 AUTO

35 SKIP OFF FREE 35 175.55 AUTO

36 294.25 AUTO 36 SKIP OFF FREE

37 463.25 AUTO 37 SKIP OFF FREE

38 SKIP OFF FREE 38 SKIP OFF FREE

39 647.25 AUTO 39 SKIP OFF FREE

PROM ITEMS DATA LENGTH INITIAL DATA REMARK

AKB ON/OFF ON

WHITE POINT (R) 0~ 63 32

WHITE POINT (G) 0~ 63 32

WHITE POINT (B) 0~ 63 32

V-SLOPE 0~ 63 25

H-SHIFT 50Hz 0~ 63 25(TV)

V-SHIFT 50Hz 0~ 63 32 (TV)

WIDTH 0~ 63 48

INITIAL SETTING OF E

PARA 0~ 63 36

CORNER 0~ 63 28

TRAP 0~ 63 32

V-AMP 0~ 63 17

S-COR 0~ 63 15

H-SHIFT 60Hz 0~ 63 31(TV)

V-SHIFT 60Hz 0~ 63 26(TV)

AGC 0~ 63 15

AUTO VCO 0~127 NG 55

MANUAL VCO 0~127 55

SUB-CONTRAST 0~ 63 63

SUB COLOUR 0~ 63 19

SUB BRIGHT 0~ 63 31

SUB TINT 0~ 63 27

RF SUB VOLUME 0~ 63 35

SP SUB VOLUME 0~ 63 55

AV TINT 0~ 63 00

AV SHARP 0~ 63 00

IGR LEVEL 0~10 05

IGR STEREO 0~ 31 24

SECAM ON/OFF ON

M ON/OFF ON

NICAM AUTO/BG/I AUTO

PSI ON/OFF ON

Y-DELAY 0~ 15 09(TV), 09(AV)

PIP ON/OFF OFF

TUNER SHARP/MURATA SHARP

TEMP 0~1 0

LANG ON/OFF ON

TDA7429 ON/OFF ON

MONOBI ON/OFF ON

AV2 ON/OFF ON

S-SYS ON/OFF ON

C-SYS ON/OFF ON

FAVOURITE CH ON/OFF ON

NVM - -

25WG3

1 SKIP POS 0 ON ->

2 SKIP POS 1 ~99 OFF ->

3 AFT ON ->

4 COLOUR SYSTEM AUTO ->

5 SOUND SYSTEM BG BG

6 IGR FORCE FM OFF ->

7 IGR STEREO STEREO ->

8 IGR BILINGUAL MAIN ->

9 NICAM FORCE FM OFF ->

10 NICAM BILINGUAL M1 ->

11 LAST POWER ON ->

12 LAST TV/AV TV ->

13 DIGIT 2 DIGIT ->

14 LANGUAGE ENGLISH THAI

NO ITEMS SETTING 1 SETTING 2

SHIPPING SETTING IX3097CEN2

15 BLUE BACK ON ->

16 AV SELECT ON/OFF OFF ->

17 AV SELECT STD/GAME STD ->

18 LAST POSITION 1 ->

19 LAST FB POSITION 1 ->

20 VOLUME 0 (MIN) ->

21 BALANCE 0 (L,R) ->

22 BASS 0 ->

23 MIDDLE 0 ->

24 TREBLE 0 ->

25 SURROUND OFF ->

26 CONTRAST 63 ->

27 COLOUR 31 ->

28 BRIGHTNESS 31 ->

29 TINT 31 ->

30 SHARPNESS 31 ->

31 TIMER CLEAR ->

32 SAVE OFF ->

33 PICTURE NR OFF ->

34 INSET TINT 31 ->

35 PIP DISPLAY POS SE ->

36 PIP SIZE L ->

37 PIP LAST POS 1 ->

38 PIP LAST TV/AV TV ->

39 FREEZE OFF ->

40 MONORAL BILINGUAL S 1 ->

MCL1 (R/C CODE =117) MCL2 (R/C CODE=169)

40 663.25 AUTO 40 SKIP OFF FREE

41 679.25 AUTO 41 SKIP OFF FREE

42 174.95 AUTO 42 SKIP OFF FREE

43 175.55 AUTO 43 SKIP OFF FREE

CH-NO Fv (MHz) SOUND SYS CH-NO Fv (MHz) SOUND SYS

44 SKIP OFF FREE 44 SKIP OFF FREE

SKIP OFF FREE SKIP OFF FREE

45 SKIP OFF FREE 45 SKIP OFF FREE

99 SKIP OFF FREE 99 SKIP OFF FREE

25WG3

OSCILLOSCOPE

TV SET

BIAS BOX : ABOUT 4.5V

P201

to get 7.75 ±

0.1Vrms.

WAVEFORM OR OTHERS

Audio signal: 400 Hz, 100% modulated

(50kHz dev.)

Out (L or R) terminal. (Terminate with

10k ohm impendence).

mode.

using Volume UP/DOWN key, so that

the 400Hz sine wave be 1.76Vp-p.

ADJUSTMENT CONDITION/PROCEDURE

1.Receive "PAL COLOUR BAR" signal.

2.Connect the Oscilloscope to the Audio

3.Call the "RF SUB VOL" in SERVICE

4.Increase or decrease "RF SUB VOL" by

C BUS CONTROL)

ADJUSTMENT POINT

1 RF SUB VOLUME

*Note : Terminated 8 ohm

Tolerence: 1.76 Vp-p ± 0.10 Vp-p.

5.Receive "COLOUR BAR" signal.

2 SP SUB VOLUME

(L Channel)

Audio signal: 400Hz, 100%modulation.

(50kHz dev.)

(1 R, 2 GND, 3 GND, 4 L, 5 NIL, 6 NIL

6.Connect Dummy load* to P3304.

7.Connect VTVM’s probe to the P3304.

C BUS CONTROL) (I

7 NIL 8 NIL)

mode.

8.Call the "SP SUB VOL" in the SERVICE

9.Increase or decrease "SP SUB VOL" by

using Volume UP/DOWN key, so that

the VTVM should read the value*.

and make sure the sound is heard from

the speakers. Then put the unit in the

no-signal state.

10. Receive the 400Hz modulated signal.

11. Turn up the volume control to Maximum

CHECKING

3 NOISE MUTE

minimum.

12. Be sure that the sound mute is effective.

13. Finally turn down the volume control to

Signal Strength: 60 ~ 70 dB

WAVEFORM OR OTHERS

COLOUR BAR" signal.

the Channel frequency displays on

screen is 210.20MHz, skip (3), (4) & (5)

steps.

"DIRECT FREQ IN".

ADJUSTMENT CONDITION/PROCEDURE

1. Receive E-10CH (210.25MHz) "PAL

SERVICE ADJUSTMENT

ADJUSTMENT POINT

VCO, AND AGC ADJUSTMENT SOUND ADJUSTMENT

2.Call "AUTO VCO" in SERVICE mode. If

C BUS CONTROL)

VCO ADJUSTMENT

3. Press FUNCTION button to call

Once finishing, "OK" message display

on screen.

Receive E-12CH (PAL COLOR BAR) signal.

Signal strength : 57 ± 1 dB ( 75ohm open)

(Tuner’s AGC Terminal) as shown in

4. Push "2", "1", "0", "2", "0".

5. Then Press FUNCTION again.

6. Press Volume UP to run "AUTO VCO".

8.Connect the oscilloscope to P201

C BUS CONTROL)

AGC ADJUSTMENT

Figure 1.

Figure 1

9. Call "AGC" in SERVICE mode.

Volume so that obtain the highest

Voltage.

direction until the voltage drops 0.1V ~

0.3V lower than the highest level.

~ 67dBµV, and make sure there is no

noise.

10. Increase or decrease "AGC" by using

11. Press Volume slowly in the opposite

12. Change the antenna input signal to 63

13. Turn up the input signal to 90 ~ 95 dBµV

to be sure that there is no cross

modulation beat.

25WG3

4-pole Magnet

6-pole Magnet

CRT NECK

Lacquer

Purity Magnet NECK

BGR

RGB

BGR

BG R

RGB

Wedge "a"

Wedge "b"

Lacquer

Wedge "c"

About 100˚

Figure a

WAVEFORM OR OTHERS

PATTERN" signal.

NORMAL mode.

opening angle in order to superpose the

blue and red colours.

opening angle in order to superpose the

green colour over the blue and red

colours.

the screen in the following steps.

ADJUSTMENT CONDITION/PROCEDURE

1. Receive the "CROSSHATCH

2. Using the remote controller, call

(Static convergence)

1. Turn the 4 - pole magnet to a proper

2. Turn the 6 - pole magnet to a proper

CONVERGENCE ADJ.

(To be done after the

ADJUSTMENT POINT

CONVERGENCE ADJUSTMENT

purity adjustment.)

(Dynamic convergence)

1. Adjust the convergence on the fringes of

Figure b

and swing the deflection coil

upward.

and "b" and swing the

deflection coil downward.

a) Fig. a :Drive the wedge at point "a"

b) Fig. b :Drive the wedge at point "a"

c) Fig. c : Drive the "c" wedge deeper

Figure c

and swing the deflection coil

rightward.

and swing the deflection coil

leftward.

d) Fig. d :Drive the "b" wedge deeper

glass tape over them.

2. Fix all the wedges on the CRT and apply

3. Apply lacquer to the deflection yoke loc k

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

Figure d

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.

Figure 3

Figure 4

Figure 2-1

WAVEFORM OR OTHERS

Adjust the beam current to ~800µA.

degausing coil.

magnetic field and keep the static

convergence roughly adjusted.

Fig.2-1 through the microscope. Adjust

ADJUSTMENT CONDITION/PROCEDURE

1. Receive the GREEN -ONLY signal.

2. Orient the raster rotation to 0 eastward.

3. Degauss the CRT enough with the

4. Maintain the purity magnet at the zero

5. Observe the points a, b, as shown in

ADJUSTMENT POINT

PURITY ADJUSTMENT

1 PURITY ADJ.

Figure 2-2

the landings to A rank requirement.

Tightening torque : 108N ± 20N

(11Kgf ± 2Kgf)

meet the A rank requirements. If not,

6. Tighten up the deflection coil screws.

7. Make sure the CRT corners landing

Figure 2-3

Rank A (On the right of CRT)

after warming up the unit for 30

minutes or longer with a beam

current over 1000µA.

switch ( S 1006) then press

factory process R/C RGB key to

stick the magnet sheet to correct it.

Note: This adjustment must be done

Note: Set the service mode by service

Rank A (On the left of CRT)

Text Key "R.G.Cy" Key

can be directly use to

change to other colours

screen.

change to green only.

to change.

* For the following colour press colour key

25WG3

1 2 3 4 5

WAVEFORM OR OTHERS

SPEC: ± 1

SCANNING LINE

signal.

using Volume key so that the center line

ADJUSTMENT CONDITION/PROCEDURE

1.Receive the "MONOSCOPE PATTERN"

2.Call the "V-SLOPE" in SERVICE mode.

3.Increase or decrease "V-SLOPE" by

C BUS CONTROL)

ADJUSTMENT POINT

HORIZONTAL, VERTICAL, DEFLECTION LOOP ADJUSTMENT.

1 V-SLOPE ADJ.

SPEC: ± 2mm

of picture matches with the edge of

PATTERN" signal.

blanking line.

1.Receive the 50Hz "MONOSCOPE

2.Call the "V-SIFT 50" in SERVICE mode.

C BUS CONTROL)

2 V-SHIFT 50

by using Volume UP/DOWN key to

adjust or align the screen center with

the CRT’s geometrical center.

PATTERN" signal.

by using Volume UP/DOWN key to

adjust or align the screen center with

the CRT’s geometrical center.

3.Increase or decrease the "V-SIFT 50"

4.Receive the 60 Hz "MONOSCOPE

5.Call the "V-SIFT 60" in SERVICE mode.

6.Increase or decrease the "V-SIFT 60"

C BUS CONTROL)

V-SHIFT 60

OVER SCAN: 8.5% ± 1.5 %

signal.

1. Receive the "MONOSCOPE PATTERN"

2. Call the "V-AMP" in SERVICE mode.

C BUS CONTROL)

3 V-AMP

using the volume UP/DOWN key to

adjust the Vertical size until it is 8.5%

3. Increase or decrease the "V-AMP" by

SPEC: ± 2mm

PATTERN" signal.

using the V olume UP/DO WN key to adjust

or align the left, and right sides of screen

overscan.

1. Receive the 50Hz "MONOSCOPE

2. Call the "H-SIFT 50" IN SERVICE MODE.

C BUS CONTROL)

are equal overscan size.

3.Increase or decrease the "H-SIFT 50" by

4 H-SHIFT 50

PATTERN" signal.

using the V olume UP/DO WN key to adjust

or align the left and right sides of screen

are equal overscan size.

4. Receive the 60Hz "MONOSCOPE

5. Call the "H-SIFT 60" IN SERVICE MODE.

6.Increase or decrease the "H-SIFT 60" by

C BUS CONTROL)

H-SHIFT 60

sure that this adjustment

with the initial bus data

"White Point (G)" &

WAVEFORM OR OTHERS

*Before adjustment , make

ADJUSTMENT CONDITION/PROCEDURE

1.Switch TV to VIDEO MODE, Blue Back:

CRT Cut - OFF ADJ.

ADJUSTMENT POINT

CUT OFF , WHITE BALANCE, SUB - BRIGHT, & FOCUS ADJUSTMENT.

"White Point (B)" are 32.

OFF, Without Video Signal.

(Use a 10:1 probe)

Range: 500mV/div

Sweep Time: 5ms/div

2.Connect the oscilloscope to TP851.

C BUS CONTROL) (I

Press "DC" mode

NORMAL mode.

signal reach 2.5Vdc ± 0.1Vdc.

3.Using the remote controller, call

4.Adjust Screen VR so that the tip of

Figure 5

Note : White Point (G)

UP " 2 " KEY

DOWN " 5 " KEY

White Point (B)

signal.

5.Receive the MONOSCOPE PATTERN

6.Call the "BKGD" in SERVICE mode.

7.Adjust "White Point (G)", "White Point

C BUS CONTROL)

2 White Balance ADJ.

y=275

UP " 3 " KEY

DOWN " 6 " KEY

As the above data can be

UP / DOWN.

*12300k x=272

(Minolta Colour Analyzer

(B)" data to have a colour temperature

of 12300k (White) Note.

CA-100)

8.Receive the "CROSSHATCH

3 SUB- BRIGHT ADJ.

PATTERN" Signal.

the No. 2 line inside the window area

will disappear.

9.Call the "SUB BRI" in SERVICE mode.

10.Adjust the "SUB-BRI" bus data, so that

C BUS CONTROL) (I

Figure 6

warm up the unit for 30 minutes or

longer at a beam current of 1200 ~

1300µA.

Signal.

TP601 (-) and TP602 (+). (Full Scale:

3.0 mA Range).

11.Receive the "MONOSCOPE PATTERN"

12.Press P-NORMAL key.

Note: Before starting this adjustment,

13.Connect the DC Milliammeter between

CHECK

4 BEAM CURRENT

14.Beam current Must be 1200 ± 100µA.

Figure 7

Receive the "MONOSCOPE PATTERN"

signal.

Using the remote control, call NORMAL

mode.

Adjust the FOCUS control so that the shaded

area of screen be in optimal focus.

5 FOCUS ADJ.

25WG3

RMg100% WWY

Same level

same distance

Figure 10

WAVEFORM OR OTHERS

signal.

Switch on service mode then press

channel up/down key to select Y DELAY

mode.

suitable number so that luminance delay

similar to color delay, shown as fig. 10.

ADJUSTMENT CONDITION/PROCEDURE

(1) Receive the PAL B/G PHILIPS pattern

(2)

(3) Press volume up/down key to select a

(4)The Y DELAY data is between 6~8.

(5) Switch off the service mode.

C DATA)

ADJUSTMENT POINT

Y DELAY ADJUSTMENT

1 Y DELAY

WAVEFORM OR OTHERS

Volume UP/DOWN key to "OFF".

ADJUSTMENT CONDITION/PROCEDURE

1. Call "SECAM" in SERVICE mode.

2. Switch the "SECAM" by using the

ADJUSTMENT POINT

OPTION ADJUSTMENT

1 SECAM SETTING

UP/DOWN key to "OFF".

1. Call "M" in SERVICE mode.

2. Switch the "M" by using theVolume

2 M SETTING

Volume UP/DOWN key to "OFF".

1. Call "S-SYS" in SERVICE mode.

2. Switch the "S-SYS" by using the

3 S-SYS SETTING

Volume UP/DOWN key to "OFF".

1. Call "C-SYS" in SERVICE mode.

2. Switch the "C-SYS" by using the

4 C-SYS SETTING

Figure 8

WAVEFORM OR OTHERS

V-LINEARITY: ± 5% Max

signal.

using the Volume UP/DOWN key to get

the best LINEARITY.

VERTICAL LINEARITY.

overscan 8.5%. Readjust or align "V-

SIFT" to match the screen center with the

CRT’s geometrical center.

ADJUSTMENT CONDITION/PROCEDURE

1. Receive the "CROSSHA TCH PATTERN"

2. Call the "S-COR" IN SERVICE mode.

3. Increase or decrease the "S-COR" by

4.Adjustment with S-COR: OVERALL

5. Readjust the "V-AMP" to make the

C BUS CONTROL)

ADJUSTMENT POINT

HORIZONTAL, VERTICAL, DEFLECTION LOOP ADJUSTMENT.

5 S-COR

WAVEFORM OR OTHERS

mode.

(Red cathode).

Range: 20 V/Div (Using 10:1 Probe)

Sweep: 20 µ sec/Div

adjustment mode. Adj SUB-COL bus

data, so that the 75% White & Red

portions of PAL Color Bar be at the

ADJUSTMENT CONDITION/PROCEDURE

1. Receive the "PAL Color Bar" signal.

2. Using remote controller, call NORMAL

3. Connect the oscilloscope to TP852

C BUS CONTROL)

ADJUSTMENT POINT

PAL CHROMA ADJUSTMENT

1 SUB COLOUR ADJ.

4. Using the R/C call "SUB COL"

same level.

5.Clear the adjustment mode.

WAVEFORM OR OTHERS

signal.

ADJUSTMENT CONDITION/PROCEDURE

1. Receive the AV NTSC 3.58 Colour Bar

2. Connect the oscilloscope to TP853.

C BUS CONTROL)

ADJUSTMENT POINT

NTSC CHROMA ADJUSTMENT

1 AV-TINT

Figure 9

TINT set to 00 at

SERVICE mode.

Note: Be sure that AV

Range: 500mV/Div

Sweep time: 20 µ sec/Div

Adjust the "SUB TIN" bus data so that

the FIRST AND SECOND portions of

the colour Bar are SAME level shown

in Figure 9.

3. Set the "SUB-TIN" mode at service mode.

WAVEFORM OR OTHERS

SETTING CONDITION

signal.

PICTURE control setting with R/C,

select the CONTRAST.

by using the VOLUME UP / DOWN key.

or not.

1. Receive the "MONOSCOPE PATTERN"

2. Press the CH UP/DOWN key for

3. Increase or decrease the CONTRAST

4. Check whether the CONTRAST is OK

signal.

1. Receive the "COLOUR BAR PATTERN"

2. Press the CH UP / DOWN key for

PICTURE control setting with the R/C,

select the COLOUR.

using the VOLUME UP / DOWN key.

not.

3. Increase or decrease the COLOUR by

4. Check whether the COLOUR is OK or

signal.

1.Receive the "MONOSCOPE PATTERN"

2.Press the CH UP / DOWN key for

PICTURE control setting with the R/C,

select the BRIGHTNESS .

BRIGHTNESS by using the VOLUME

UP / DOWN key.

or not.

3.Increase or decrease the

1. Receive the "MONOSCOPE PATTERN"

4.Check whether the BRIGHTNESS is OK

signal.

2. Press the CH UP / DOWN key for

signal.

PICTURE control setting with the R/C,

select the SHARPNESS.

by using the VOLUME UP / DOWN key.

or not.

3. Increase or decrease the SHARPNESS

1. Receive the "MONOSCOPE PATTERN"

4. Check whether the SHARPNESS is OK

select WHITE TEMP.

2. Press the CH UP / DOWN key for

3. Increase or decrease the WHITE TEMP

by using the VOLUME UP / DOWN key.

or not.

4. Check whether the WHITE TEMP is OK

25WG3

CHECKING POINT

CHECKING OPERATION (VIDEO & AUDIO)

1 CONTRAST

WAVEFORM OR OTHERS

signal (100% White Color Bar Sound

400 Hz 100% Modulation)

ohm impendence. Make sure the output

is as specified (1.0 Vp-p ± 3 dB)

ADJUSTMENT CONDITION/PROCEDURE

1. Receive the "PAL COLOUR BAR"

2. Terminate the Video output with a 75

3. Terminate the Audio output with a 10

2 COLOUR

Kohm impendence. Make sure the O/P

is as specified (1.76 Vp-p ± 3 dB).

controller, make sure that the modes

1. Using the TV/AV key on the remote

3 BRIGHTNESS

WAVEFORM OR OTHERS

(AV2).

change in order of TV, AV1, AV2 & TV

again and that the video & audio output

are according to the input terminal for

each mode.

channel to AV2 automatically.

1. Connect Video signal to FRONT AV

2. Make sure Channel switch from other

ADJUSTMENT CONDITION/PROCEDURE

4 SHARPNESS

signal.

1. Receive the "MONOSCOPE PATTERN"

ground, make sure the protector ON

2. Set CONTRAST MAX.

3. Set BRIGHT MAX.

4. While the R or B or G Cathode short to

5 WHITE TEMP

WAVEFORM OR OTHERS

Capacitor short testing in + B line,

check all possible damaged

signal.

cathode (D608).

2. Connect output of Bias Box to D601

3. Set voltage of Bias Box to 20V and

make sure the protector is work.

and switch to standby mode.

ADJUSTMENT CONDITION/PROCEDURE

1. Receive the "MONOSCOPE PATTERN"

components on +B line.

1. Once finish rectified Electrolytic

A/V INPUT/OUTPUT CHECKING

1 VIDEO & AUDIO

OUTPUT CHECKING

ADJUSTMENT POINT

INPUT CHECKING

2 VIDEO & AUDIO

3 AUTO SELECT

PROTECTOR OPERATION CHECKING

BEAM PROTECTOR

ADJUSTMENT POINT

PROTECTOR OPERATION CHECKING

2 H, V PROTECTOR

OTHER PROTECTOR 3

25WG3

WAVEFORM OR OTHERS

If nothing is display mean

contrast, colour, bright, tint,

sharpness are all in normal

setting.

SETTING CONDITION

BASS: CENTER

MIDDLE: CENTER

TREBLE: CENTER

BALANCE: CENTER

condition to normal . When the

NORMAL key is pressed, all the initial

sound control settings will be preset to

normal setting as listed below:

1. Receive the MUSIC SOUND SIGNAL.

2. Press NORMAL key to set the sound

SURROUND control setting with the R/C.

Mode as follows, MOVIE/DISCO/POP/

ROCK/CLASSIC/SPORTS/SIMULATED/

OFF.

1. Receive the MUSIC SOUND SIGNAL.

2. Press the CH UP / DOWN key for

3. Press Volume Up to switch Surround

PATTERN" signal. Press the SYSTEM

key to set the COLOUR SYSTEM

MODE to AUTO mode. Check whether

1. Receive the "PAL COLOUR BAR

4. Make sure each mode is working properly.

the colour of the PAL Colour Bar signal

is OK or not.

Receive the "NTSC 4.43 COLOUR BAR"

signal. Press the SYSTEM key to set the

COLOUR SYSTEM mode to AUTO mode.

Check whether the colour of the N4.43

Colour Bar signal is OK or not.

Receive the "NTSC 3.58 COLOUR BAR"

signal. Press the SYSTEM key to set the

COLOUR SYSTEM mode to AUTO

mode. Check whether the colour of the

N3.58 Colour Bar signal is OK or not.

mode as follows, SA VE/ A V SELECT/ NR/

BLUE BACK/OSD.

make sure each mode is working

properly.

1.Press FUNCTION key to select each

2.Press Volume Up to switch each mode,

make sure the sound is heard from the

speakers. Then put the unit in no signal

state.

1. Receive "PAL COLOUR BAR" signal.

2. Turn up the volume control to maximum,

3. Be sure that the sound mute is effective.

4. Finally turn down the volume of CTV to

control setting with the R/C, select

minimum.

1. Receive "DUAL SOUND" signal.

2. Press CH UP/DOWN key for SOUND

BILINGUAL.

SOUND 1 & SOUND 2.

are okay separately or not.

3. Press VOLUME UP/DOWN to select

4. Check whether SOUND 1 & SOUND 2

CHECKING POINT

12 NORMAL

WAVEFORM OR OTHERS

If nothing is display mean

contrast, colour, bright, tint,

sharpness are all in normal

setting.

SETTING CONDITION

signal.

condition to normal . When the

NORMAL key is pressed, all the initial

1. Receive the "COLOUR BAR PATTERN"

2. Press NORMAL key to set the picture

13 SURROUND

Contrast: MAX.

Colour: CENTER

Brightness: CENTER

Tint: CENTER

Sharpness: CENTER

picture control settings will be preset to

normal setting as listed below:

14 COLOUR SYSTEM

SOUND control setting with the R/C,

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

the channel number in green colour under

AFT ON condition.

1. Receive the MUSIC SOUND SIGNAL.

2. Press the CH UP / DOWN key for

CHECKING

15 FUNCTION

select the BASS.

using the VOLUME UP / DOWN key.

frequency) is OK or not.

3. Increase or decrease the BASS by

4. Check whether the BASS (low

control setting with the R/C, select the

MIDDLE.

using the VOLUME UP / DOWN key.

frequency) is OK or not.

1.Receive the MUSIC SOUND SIGNAL.

2. Press the CH UP / DOWN ke y for SOUND

3.Increase or decrease the MIDDLE by

4.Check whether the MIDDLE (MIDDLE

16 NOISE MUTE

control setting with the R/C, select the

TREBLE.

using the VOLUME UP / DOWN key.

1.Receive the MUSIC SOUND SIGNAL.

2. Press the CH UP / DOWN ke y for SOUND

3.Increase or decrease the TREBLE by

4.Check whether the TREBLE (HIGH

17 BILINGUAL

control setting with the R/C, select the

BALANCE.

speaker BALANCE by using the

frequency) is OK or not.

1.Receive the MUSIC SOUND SIGNAL.

2. Press the CH UP / DOWN ke y for SOUND

VOLUME UP / DOWN key.

3.Increase or decrease the left or right

4.Check whether the BALANCE of left and

right speakers is OK or not.

CHECKING POINT

CHECKING OPERATION (VIDEO & AUDIO)

6 NORMAL

DISPLAY

7 CH COLOUR

8 BASS

9 MIDDLE

10 TREBLE

11 BALANCE

25WG3

If bus error happen, the LED RED (pin (30) of IC1001 low) indicator starts flashing and the power is turned off.

The power key is still effective.

E PROM (S24C04A)

IC1002

1 chip IC (TDA8375)

IC201

Sound processor IC (TDA7429S)

IC302

PSI IC (TDA4671)

IC401

PLL (ST6HD64)

TU201

Check F750.

Blown out.

Replace the fuse.

The fuse is again

blown out.

Check T701 pin(1)

voltage (approx. 310V

at 220VAC).

Check D704, and

IC701, C730, C731.

Check R701, R703 and

D703.

Check D708 and D714.

Check IC703.

Check secondary main + B

(approx. 120V).

D1101 (power LED

green) turn ON ?

Check CRT connector

K1-K5 bias.

Check IC851

and peripheral

parts.

Check (K) wire

and plug.

Horizontal circuit oscillate?

Check IC201,

Q603, IC202

and Q601.

D1101 (power LED red)

turns on or turns

ON/OFF ?

Check the protector

circuit.

Bus error mode.

See Figure 1.

NO RASTER

Normal

Abnormal

YES

ON/OFF

Does the snow noise appear on

the picture tube at max contrast

and brightness control?

Snow noise increase.

Check the TUNER 33V.

Check IC203,

R227.

Check the tuner AGC.

Check IC201.

Check the

tuner circuit.

NO PICTURE

Normal

Abnormal

No snow noise.

Check the voltage of

S-convertor (12V).

Check IC301, Q202, Q204

and its related parts.

Check IC201 and

peripheral circuit.

Check R318, C303.

Does noise or signal appear at pin (27) of IC201?

Does noise or signal appear at pins (29), (30)

of IC302?

Does noise or signal appear at pins (2), (5)

of IC3301?

Check (FS) connector, IC3301 and their

peripheral circuit.

Check IC302 and peripheral circuit.

Does noise or signal appear at

pin (16) of IC201?

Check PIF circuit and

its related parts.

Does noise or signal

appear at pin (24) of

IC201?

YES

Normal

Abnormal

NO SOUND

Check IC201, IC301, IC302 and peripheral circuit.

Check IC706, C355, IC302 and peripheral circuit.

Check IC201, C603, C604, C609 and R605.

NEITHER VERTICAL NOR

HORIZONTAL SYNCHRONIZATION

TROUBLESHOOTING

Figure 1

25WG3

Readjust vertical size.

Vertical size is abnormal/non linearity.

Check R503, R504 and R505.

Check IC501 bias.

DEFECTIVE VERTICAL AMP.

AND VERTICAL LINEARITY

NO VERTICAL SCAN

Normal

Abnormal

Check R503, C502, R501, C503 and C501.

Check R638,R620 and R512.

Is some colour produced in B/W

broadcast reception?

Check IC201 and bias control circuit.

Correct and change the wrong parts.

Check IC801,IC401,

X801, X802, C802,

C803 and C804.

(PAL/NTSC)

(SECAM)

Check IC901 and its

related parts.

NO SPECIFIC COLOUR

YES

NO SPECIFIC COLOUR

(NO COLOUR SYNCHRONIZATION)

Normal

Abnormal

Check IC201, R802,

R803, R804 and R412.

Is the white balance

properly adjusted?

Readjust the white

balance.

The picture colour is yellow.

The picture colour is magenta.

The picture colour is cyan.

Check pins (2), (8) of IC851

and its adjacent circuit.

Check pins (7), (3) of IC851

and its adjacent circuit.

Check pins (1), (9) of IC851

and its adjacent circuit.

2SC3808

2SC1906

PX0003PE

TDA8351

SOLID STATE DEVICE BASE DIAGRAM

TOP VIEW

IX3097CE

TDA4671

TDA8375

S24C04A1

FX0024CE

TDA4665

TDA7429

2SK5832SK30AGKIA7045P

2SA1015

RC102M

2SA1037

SIDE VIEW

2SC2412

2SC1815

PX0274CE

2SC3886

PQ12RD

PQ09RD

PQ05RD

KIA7812P

KIA7805P

KIA7808P

DX0355CE

2SA1837

2SC4793

AN5275

STR6656

TDA6107

M51497L

+ 30 hidden pages