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25WG3

SY8A725WG3///

SERVICE MANUAL

SHARP CORPORATION

COLOUR TELEVISION

Chassis No. SS-1

MODEL

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.

 WARNING

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

Page

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

25WG3

COLOUR

TELEVISION

MODEL

25WG3

SERVICE

MANUAL

Содержание 25WG3

Страница 1: ... 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 Page 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 O...

Страница 2: ...stem 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 ...

Страница 3: ...E 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 1 Picture tube in this receiver employs integral implosion protection 2 Replace with tube of the same type number for continued safety 3 Do no...

Страница 4: ...R 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 SU...

Страница 5: ...OF E 2 PROM MCL1 MCL2 CHANNEL SETTING 1 48 25 AUTO 1 46 25 AUTO 2 62 25 AUTO 2 64 25 AUTO 3 77 25 AUTO 3 86 25 AUTO 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 OF...

Страница 6: ...UTO 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 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 CON...

Страница 7: ...NDITION PROCEDURE VCO AND AGC ADJUSTMENT SOUND ADJUSTMENT 2 SP SUB VOLUME I 2 C BUS CONTROL 5 Receive COLOUR BAR signal Audio signal 400Hz 100 modulation 50kHz dev 6 Connect Dummy load to P3304 7 Connect VTVM s probe to the P3304 1 R 2 GND 3 GND 4 L 5 NIL 6 NIL 7 NIL 8 NIL 8 Call the SP SUB VOL in the SERVICE mode 9 Increase or decrease SP SUB VOL by using Volume UP DOWN key so that the VTVM shoul...

Страница 8: ...ERN 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 ...

Страница 9: ... FOCUS control so that the shaded area of screen be in optimal focus 5 FOCUS ADJ Figure 7 1 Receive the 50Hz MONOSCOPE PATTERN signal 2 Call the V SIFT 50 in SERVICE mode 3 Increase or decrease the V SIFT 50 by using Volume UP DOWN key to adjust or align the screen center with the CRT s geometrical center 4 Receive the 60 Hz MONOSCOPE PATTERN signal 5 Call the V SIFT 60 in SERVICE mode 6 Increase ...

Страница 10: ...53 Range 500mV Div Sweep time 20 µ sec Div 3 Set the SUB TIN mode at service mode Adjust the SUB TIN bus data so that the FIRST AND SECOND portions of the colour Bar are SAME level shown in Figure 9 NTSC CHROMA ADJUSTMENT NO ADJUSTMENT POINT 1 AV TINT I 2 C BUS CONTROL ADJUSTMENT CONDITION PROCEDURE WAVEFORM OR OTHERS Figure 9 Note Be sure that AV TINT set to 00 at SERVICE mode 1 Receive the PAL B...

Страница 11: ...T SETTING CONDITION WAVEFORM OR OTHERS 1 Receive the PAL COLOUR BAR signal 100 White Color Bar Sound 400 Hz 100 Modulation 2 Terminate the Video output with a 75 ohm impendence Make sure the output is as specified 1 0 Vp p 3 dB 3 Terminate the Audio output with a 10 Kohm impendence Make sure the O P is as specified 1 76 Vp p 3 dB A V INPUT OUTPUT CHECKING NO ADJUSTMENT POINT 1 VIDEO AUDIO OUTPUT C...

Страница 12: ... 2 Press NORMAL key to set the sound condition to normal When the NORMAL key is pressed all the initial sound control settings will be preset to normal setting as listed below BASS CENTER MIDDLE CENTER TREBLE CENTER BALANCE CENTER NO CHECKING POINT 12 NORMAL SETTING CONDITION WAVEFORM OR OTHERS If nothing is display mean contrast colour bright tint sharpness are all in normal setting 1 Receive the...

Страница 13: ...mal Abnormal Abnormal Abnormal YES YES NO NO 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 B Normal Normal Abnormal Abnormal No snow noise Check the voltage of S convertor 12V Check IC301 Q202 Q204 and its related parts Check IC2...

Страница 14: ...FIC 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 SOLID STATE ...

Страница 15: ... 1000 ohms M Meg ohm 2 All resistors are 1 8 watt unless otherwise noted 3 All capacitors µF unless otherwise noted P µµF VOLTAGE MEASUREMENT CONDITIONS 1 Voltage in parenthesis measured with no Signal 2 Voltages without parenthesis measured with 3mV B W or colour Signal 3 All the voltages in each point are measured with VTVM WAVEFORM MEASUREMENT CONDITIONS 1 Colour bar generator signal of 1 0V pe...

Страница 16: ...16 25WG3 A B C D E F G H 1 2 3 4 5 6 7 BLOCK DIAGRAM MAIN 1 UNIT BLOCK DIAGRAM ...

Страница 17: ...17 25WG3 7 8 9 10 11 12 13 ...

Страница 18: ...18 25WG3 A B C D E F G H 1 2 3 4 5 6 7 MAIN 2 UNIT BLOCK DIAGRAM ...

Страница 19: ...19 25WG3 7 8 9 10 11 12 13 ...

Страница 20: ...20 25WG3 A B C D E F G H 1 2 3 4 5 6 7 CRT FRONT S OUT UNIT BLOCK DIAGRAM ...

Страница 21: ...21 25WG3 7 8 9 10 11 12 13 ...

Страница 22: ...22 25WG3 A B C D E F G H 1 2 3 4 5 6 7 CHASSIS LAYOUT ...

Страница 23: ...23 25WG3 7 8 9 10 11 12 13 ...

Страница 24: ...24 25WG3 A B C D E F G H 1 2 3 4 5 6 7 SCHEMATIC DIAGRAM MAIN 1 UNIT SCHEMATIC DIAGRAM ...

Страница 25: ...25 25WG3 7 8 9 10 11 12 13 ...

Страница 26: ...26 25WG3 A B C D E F G H 1 2 3 4 5 6 7 MAIN 2 UNIT SCHEMATIC DIAGRAM ...

Страница 27: ...27 25WG3 7 8 9 10 11 12 13 ...

Страница 28: ...28 25WG3 A B C D E F G H 1 2 3 4 5 6 7 A B C D E F G H 1 2 3 4 5 6 CRT FRONT S OUT UNIT SCHEMATIC DIAGRAM ...

Страница 29: ...29 25WG3 7 8 9 10 11 12 13 7 8 9 10 11 12 ...

Страница 30: ... 5 6 7 REMOTE CONTROL UNIT SCHEMATIC DIAGRAM NOTE The parts here shown are supplied as an assembly but not independently TUNER SCHEMATIC DIAGRAM VTUVTST6HD64 NOTE The parts here shown are supplied as an assembly but not independently ...

Страница 31: ...31 25WG3 7 8 9 10 11 12 13 M E M O ...

Страница 32: ...32 25WG3 A B C D E F G H 1 2 3 4 5 6 7 PRINTED WIRING BOARD ASSEMBLIES MAIN 1 UNIT ...

Страница 33: ...33 25WG3 7 8 9 10 11 12 13 ...

Страница 34: ...34 25WG3 A B C D E F G H 1 2 3 4 5 6 7 A B C D E F G H 1 2 3 4 5 6 MAIN 2 UNIT SIDE A MAIN 2 UNIT SIDE B CRT UNIT ...

Страница 35: ...35 25WG3 7 8 9 10 11 12 13 FRONT UNIT 7 8 9 10 11 12 S OUT UNIT ...

Страница 36: ...Ref No Part No Description Code Ref No Part No Description Code 25WG3 36 M E M O ...

Страница 37: ...2M 1 R KRC102M AA Q3304 VSKRC102M 1 R KRC102M AA DIODES AND VARISTOR D3301 RH DX0475CEZZ R DX0475CE AB D3302 RH DX0475CEZZ R DX0475CE AB D3303 RH DX0475CEZZ R DX0475CE AB D3304 RH DX0475CEZZ R DX0475CE AB å VA750 RH VX0048CEZZ R Varistor VX0048CE AE COIL å L751 RCiLF0031PEZZ R Coil AR CAPACITORS å C750 RC FZ012SGEZZ R 0 22 AC250V AE å C751 RC FZ008SCEZZ R 0 1 AC250V AE C3301 VCEAGA1HW107M R 100 50...

Страница 38: ...255CE AC D608 RH DX0475CEZZ R DX0475CE AB D609 RH DX0127CEZZ R DX0127CE AC D610 RH DX0279CEZZ R DX0279CE AB D611 RH DX0475CEZZ R DX0475CE AB D616 RH DX0475CEZZ R DX0475CE AB D701 RH DX0474CEZZ R DX0474CE AE D702 RH DX0475CEZZ R DX0475CE AB D703 RH EX0619GEZZ R Zener EX0619GE AA D704 RH DX0478CEZZ R DX0478CE AL D708 RH EX0641GEZZ R Zener EX0641GE AA D709 RH DX0471CEZZ R DX0471CE AE D710 RH DX0471CE...

Страница 39: ...p 50V Ceramic AA C706 VCKYPH3DB561K R 560p 2000V Ceramic AC C707 VCKYPA1HB471K R 470p 50V Ceramic AA C708 VCEAGA1VW107M R 100 35V Electrolytic AC C709 RC KZ0035CEZZ R 220p 2kV Ceramic AB C710 RC KZ0016CEZZ R 0 01 1 5kVCeramic AC C711 RC KZ0016CEZZ R 0 01 1 5kVCeramic AC C712 RC KZ0016CEZZ R 0 01 1 5kVCeramic AC C713 RC KZ0016CEZZ R 0 01 1 5kVCeramic AC C714 VCFYFA1HA104J R 0 1 50V M Polypro AA C71...

Страница 40: ...8 2M 1 2W Solid AA å R717 VRC UA2HG825K R 8 2M 1 2W Solid AA R718 VRD RA2BE102J R 1k 1 8W Carbon AA R719 VRD RA2BE332J R 3 3k 1 8W Carbon AA R720 VRN VV3DB6R8J R 6 8 2W Metal Film AB R721 VRD RA2BE102J R 1k 1 8W Carbon AA R722 VRS SV3AB683J R 68k 1W Metal Oxide AA R723 VRD RA2BE472J R 4 7k 1 8W Carbon AA R724 VRD RA2BE472J R 4 7k 1 8W Carbon AA R725 VRN KT3LB2R2J R 2 2 3W Metal Film AF R726 VRD RA...

Страница 41: ...GA1CW476M R 47 16V Electrolytic AB C406 VCEAGA1AW477M R 470 10V Electrolytic AC C407 VCEAGA1HW475M R 4 7 50V Electrolytic AB C408 VCEAGA1CW476M R 47 16V Electrolytic AB C409 VCKYCY1EF104Z R 0 1 25V Ceramic AA C410 VCKYCY1HF103Z R 0 01 50V Ceramic AA C411 VCKYCY1HF103Z R 0 01 50V Ceramic AA C412 VCKYCY1EF104Z R 0 1 25V Ceramic AA C413 VCKYCY1EF104Z R 0 1 25V Ceramic AA C414 VCKYCY1EF104Z R 0 1 25V ...

Страница 42: ...JF101J R 100 1 16W Metal Oxide AA R1037 VRS CY1JF561J R 560 1 16W Metal Oxide AA R1041 VRS CY1JF103J R 10k 1 16W Metal Oxide AA R1042 VRS CY1JF562J R 5 6k 1 16W Metal Oxide AA R1043 VRS CY1JF101J R 100 1 16W Metal Oxide AA R1044 VRS CY1JF472J R 4 7k 1 16W Metal Oxide AA R1045 VRS CY1JF103J R 10k 1 16W Metal Oxide AA R1046 VRS CY1JF102J R 1k 1 16W Metal Oxide AA R1048 VRS CY1JF153J R 15k 1 16W Meta...

Страница 43: ...402 QCNW 0024PEZZ Connecting Cord CN752 QCNW 0022PEZZ Connecting Cord CN753 QCNW 0023PEZZ Connecting Cord CN851 QCNW 2187PEZZ R Connecting Cord AG CN852 QCNW 0020PEZZ Connecting Cord CN1101 QCNW 0025PEZZ R Connecting Cord AF CN3302 QCNW 2222PEZZ R Connecting Cord AK CN3306 QCNW 2224PEZZ R Connecting Cord AH SUPPLIED ACCESSORIES QACCZ3008PEZZ R AC Cord AN QCNW 2193PEZZ R Connecting Cord AK RRMCG139...

Страница 44: ...ochigi 329 2193 Japan COPYRIGHT C 1998 BY SHARP CORPORATION ALL RIGHTS RESERVED No part of this publication may be reproduced stored in a retrieval system or transmitted in any form or by any means electronic mechanical photocopying recording or otherwise without prior written permission of the publisher TQ0580 S Dec 1998 Printed in JAPAN NA NS 25WG3 ...

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