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Symphonic CST274FE Service Manual

27" color television
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SERVICE MANUAL
27" COLOR TELEVISION
CST274FE

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Summary of Contents for Symphonic CST274FE

  • Page 1 SERVICE MANUAL 27" COLOR TELEVISION CST274FE...

  • Page 2: Table Of Contents

    IMPORTANT SAFETY NOTICE Proper service and repair is important to the safe, reliable operation of all Funai Equipment. The service procedures recommended by Funai and de- scribed in this service manual are effective methods of performing service operations. Some of these service special tools should be used when and as recommended.

  • Page 3: Specifications

    SPECIFICATIONS <TUNER> ANT. Input ------------------- 75ohm Unbal., F type Reference Level ----------- 20Vp-p (CRT Green Cathode) Test Input Signal ---------- 400Hz 30% modulation Description Condition Unit Nominal Limit 1. Intermediate Freq. Picture 45.75 Sound 41.25 2. Peak Picture Sens dBµv CATV dBµv dBµv...

  • Page 4: Important Safety Precautions

    IMPORTANT SAFETY PRECAUTIONS Prior to shipment from the factory, our products are strictly inspected for recognized product safety and electrical codes of the countries in which they are to be sold. However, in order to maintain such compliance, it is equally important to implement the following precautions when a set is being serviced.
  • Page 5 ing is performed that involves B+, horizontal de- earth ground. If a voltage reading in excess of 1.0V flection or high voltage. Correct operation of the X- is obtained, remove and reinsert the AC power radiation protection circuits also must be recon- plug in the opposite polarity and again measure firmed each time they are serviced.
  • Page 6 Precautions during Servicing 3) Align the lengths of the wires to be connected. In- sert the wires fully into the connector. A. Parts identified by the ( # ) symbol are critical for 4) Use the crimping tool to crimp the metal sleeve at safety.
  • Page 7 Safety Check after Servicing Examine the area surrounding the repaired location Chassis or Secondary Conductor for damage or deterioration. Observe that screws, parts and wires have been returned to original posi- tions. Afterwards, perform the following tests and con- Primary Circuit Terminals firm the specified values in order to verify compliance with safety standards.

  • Page 8: Standard Notes For Servicing

    STANDARD NOTES FOR SERVICING Circuit Board Indications How to Remove / Install Flat Pack-IC a. The output pin of the 3 pin Regulator ICs is indicat- 1. Removal ed as shown. With Hot-Air Flat Pack-IC Desoldering Machine: (1) Prepare the hot-air flat pack-IC desoldering ma- Top View Bottom View chine, then apply hot air to the Flat Pack-IC (about...
  • Page 9 3. The flat pack-IC on the CBA is affixed with glue, so With Soldering Iron: be careful not to break or damage the foil of each (1) Using desoldering braid, remove the solder from pin or the solder lands under the IC when remov- all pins of the flat pack-IC.
  • Page 10 2. Installation soldering iron to center of the flat pack-IC and heat up. Then remove (glue will be melted). (Fig. S-1-6) (1) Using desoldering braid, remove the solder from (5) Release the flat pack-IC from the CBA using twee- the foil of each pin of the flat pack-IC on the CBA zers.
  • Page 11 Instructions for Handling Semiconductors Electrostatic breakdown of the semiconductors may occur due to a potential difference caused by electro- static charge during unpacking or repair work. 1. Ground for Human Body Be sure to wear a grounding band (1MΩ) that is prop- erly grounded to remove any static electricity that may be charged on the body.

  • Page 12: Cabinet Disassembly Instructions

    CABINET DISASSEMBLY INSTRUCTIONS 1. Disassembly Flowchart Note : (1) Order of steps in procedure. When reassembling, This flowchart indicates the disassembly steps for the follow the steps in reverse order.These numbers cabinet parts, and the CBA in order to gain access to are also used as the Identification (location) No.
  • Page 13 Front Cabinet [3] Main CBA Control Plate [1] Rear Cabinet Fig. 1 Fig. 3 Degaussing Coil Anode Cap [2] CRT Ground Wire [1] Rear Cabinet Front Front Cabinet Cabinet [4] CRT Control Plate Control Plate Fig. 2 Fig. 4 L2807DC...
  • Page 14 TV Cable Wiring Diagram DG691 DEGAUSSING COIL SP802 SP801 MAIN CBA CLN802 CLN801 CN802 CN801 CN691 WH301A TU11 FLYBACK TUNER TRANSFORMER CN571 T571 WH501A TO CRT GROUND AC601 WH501B AC CORD CN1501 FOCUS JK1501 SCREEN WH301B ANODE Fig. 5 L2807DC...

  • Page 15: Electrical Adjustment Instructions

    ELECTRICAL ADJUSTMENT INSTRUCTIONS How to set up the service mode: General Note: "CBA" is abbreviation for "Circuit Board Assem- Service mode: bly." 1. Use the service remote control unit. NOTE: 2. Turn the power on. (Use main power on the TV Electrical adjustments are required after replacing unit.) circuit components and certain mechanical parts.
  • Page 16 2. Initial Setting 1. Press "MENU" button on the service remote con- General trol unit. Then select "COLOR" (CLR) display. 1. Enter the Service mode. (See page 5-1) 2. Press "CH o/p" buttons on the service remote 2. Press "VOL p" button on the service remote control control unit so that the value of "COLOR"...
  • Page 17 6. Purity Check S-SRP 1. Press "MENU" button on the service remote con- 1. Enter the Service mode. (See page 5-1) trol unit. Then select "S-SHARPNESS" (S-SRP) 2. Press "7" button on the remote control unit. Each display. time pressing 7" button on the remote control unit, 2.
  • Page 18 8. H. Position Adjustment 10. V. Position Adjustment Purpose: To obtain correct horizontal position of Purpose: To obtain correct vertical width of screen image. screen image. Symptom of misadjustment: If V. Position is incor- Symptom of Misadjustment: If H. Position is incor- rect, vertical height of image on the screen may not be rect, horizontal position of image on the screen may properly displayed.
  • Page 19 13. Software Reset 16. Cut-off Adjustment Purpose: To adjust the beam current of R, G, B, and To reset software, press “5” button on the remote con- screen voltage. trol unit for at least 5 seconds after pressing “CH Symptom of Misadjustment: White color may be RETURN”...
  • Page 20 17. White Balance Adjustment 18. Sub-Brightness Adjustment Purpose: To mix red, green and blue beams correctly Purpose: To get proper brightness. for pure white. Symptom of Misadjustment: If Sub-Brightness is Symptom of Misadjustment: White becomes bluish incorrect, proper brightness cannot be obtained by or reddish.
  • Page 21 22. Convergence Adjustment The following adjustments normally are not attempted in the field. Only when replacing the Purpose: To obtain proper convergence of red, green CRT then adjust as a preparation. and blue beams. 20. Purity Adjustment Symptom of Misadjustment: If Convergence Adjust- ment is incorrect, the edge of white letters may have Purpose: To obtain pure color.
  • Page 22 23. Yh, Yv, Xv Adjustment 1. Adjust the volume of Deflection Yoke(Yh, Yv, Xv) to get good convergence. FRONT L2808EA...

  • Page 23: Block Diagrams

    BLOCK DIAGRAMS System Control Block Diagram L2808BLS...
  • Page 24 IF/Video Block Diagram L2808BLIF...
  • Page 25 Audio Block Diagram L2808BLA...
  • Page 26 CRT/H.V. Block Diagram L2808BLCRT...
  • Page 27 Power Supply Block Diagram L2808BLP...

  • Page 28: Schematic Diagrams / Cba's And Test Points

    SCHEMATIC DIAGRAMS / CBA'S AND TEST POINTS Standard Notes Many electrical and mechanical parts in this chassis have special characteristics. These characteristics often pass unnoticed and the protection afforded by them cannot necessarily be obtained by using replacement compo- nents rated for higher voltage, wattage, etc. Replacement parts that have these special safety characteristics are identified in this manual and its supplements;...
  • Page 29 LIST OF CAUTION, NOTES, AND SYMBOLS USED IN THE SCHEMATIC DIAGRAMS ON THE FOLLOWING PAGES: 1. CAUTION: FOR CONTINUED PROTECTION AGAINST RISK OF FIRE, REPLACE ONLY WITH SAME TYPE_A,_V FUSE. ATTENTION: UTILISER UN FUSIBLE DE RECHANGE DE MÊME TYPE DE_A,_V. 2.
  • Page 30 Main 1/4 Schematic Diagram VIDEO SIGNAL MAIN 1/4 Ref No. Position IC111 IC151 TRANSISTORS Q111 Q131 Q161 Q321 CONNECTOR CN301 L2808SCM1...
  • Page 31 Main 2/4 Schematic Diagram VIDEO SIGNAL AUDIO SIGNAL MAIN 2/4 Ref No. Position IC431 IC771 IC801 TRANSISTORS Q751 Q761 Q791 Q792 Q793 Q794 Q801 Q811 CONNECTORS CN801 CN802 L2808SCM2...
  • Page 32 Main 3/4 Schematic Diagram CAUTION ! IF SIGNAL Fixed voltage ( or Auto voltage selectable ) power supply circuit is used in this unit. CAUTION: FOR CONTINUED PROTECTION AGAINST RISK NOTE : VIDEO SIGNAL If Main Fuse (F601) is blown, check to see that all components in the power supply OF FIRE, REPLACE ONLY WITH SAME TYPE 4A, 125V FUSE.
  • Page 33 Main 4/4 & CRT Schematic Diagram MAIN 4/4 Ref No. Position Ref No. Position Ref No. Position TRANSISTORS CONNECTORS Q1511 IC551 CN571 Q1512 TRANSISTORS WH301A Q1521 Q511 WH501A Q1522 Q512 TEST POINTS Q1531 Q547 TP591 Q1532 Q551 TP592 CONNECTORS Q552 TP601 CN1501 Q561...
  • Page 34 Main CBA Top View CAUTION ! CAUTION: FOR CONTINUED PROTECTION AGAINST RISK BECAUSE A HOT CHASSIS GROUND IS PRESENT IN THE POWER Fixed voltage ( or Auto voltage selectable ) power supply circuit is used in this unit. OF FIRE, REPLACE ONLY WITH SAME TYPE 4A, 125V FUSE. SUPPLY CIRCUIT, AN ISOLATION TRANSFORMER MUST BE USED.
  • Page 35 Main CBA Bottom View CAUTION: FOR CONTINUED PROTECTION AGAINST RISK BECAUSE A HOT CHASSIS GROUND IS PRESENT IN THE POWER CAUTION ! OF FIRE, REPLACE ONLY WITH SAME TYPE 4A, 125V FUSE. Fixed voltage ( or Auto voltage selectable ) power supply circuit is used in this unit. SUPPLY CIRCUIT, AN ISOLATION TRANSFORMER MUST BE USED.
  • Page 36 CRT CBA Top View CRT CBA Bottom View CRT CBA Ref No. Position TRANSISTORS Q1511 Q1512 Q1521 Q1522 Q1531 Q1532 CONNECTORS CN1501 WH301B WH501B WF14 WF15 Q1521 Q1521 Q1511 Q1511 Collector Base Collector Base Q1531 Base WF13 Q1531 Collector 7-15 7-16 BL2700F01012-2...

  • Page 37: Waveforms

    WAVEFORMS WF1 ~ WF16 = Waveforms to be observed at Waveform check points. (Shown in Schematic Diagram.) Input: NTSC Color Bar Signal (with 1kHz Audio Signal) INITIAL POSITION: Unplug unit from AC outlet for at least 5 minutes. reconnect to AC outlet and then turn power on. (Brightness---Center Color---Center Tint --- Center Contrast---Approx 70%) 1DIV: 2V 20µs 1DIV: 0.5V 20µs...
  • Page 38 WF1 ~ WF16 = Waveforms to be observed at Waveform check points. (Shown in Schematic Diagram.) Input: NTSC Color Bar Signal (with 1kHz Audio Signal) INITIAL POSITION: Unplug unit from AC outlet for at least 5 minutes. reconnect to AC outlet and then turn power on. (Brightness---Center Color---Center Tint --- Center Contrast---Approx 70%) 1DIV: 200V 20µs WF13...

  • Page 39: Wiring Diagram

    WIRING DIAGRAM CN801 CLN801 1 SP-L SP801 SP-GND SPEAKER L-CH CN802 CLN802 1 SP-R SP802 SP-GND SPEAKER R-CH ANODE TU11 TUNER UNIT V501 MAIN CBA BL2700F01012-1 CN691 FOCUS CN1501 T571 SCREEN WH301B WH301A CLN301 BLUE BLUE GREEN GREEN WH501B WH501A CLN501 CRT CBA HEATER 3...

  • Page 40: Ic Pin Functions

    IC PIN FUNCTIONS IC111 (TV Micro Controller) Signal Name Function Signal Name Function 35 N.U. Not Used 36 N.U. Not Used CNVSS 37 V RAMP F/B V Ramp Feed Back N.U. Not Used 38 V RAMP OUT Vertical Output N.U. Not Used 39 V RAMP CAP V Ramp OSC Capacitor...
  • Page 41 Signal Name Function 70 RCV-IN Input For Remote Control 71 N.U. Not Used White Balance Adjustment 72 I2C-OPEN Judgement 73 AFT-IN AFT Voltage Input 74 DG-ON-H Degaussing Coil Control 75 AGC AGC Voltage Input 76 PROTECT-3 Power Supply Protection 77 N.U. Not Used 78 N.U.
  • Page 42 EXPLODED VIEWS Cabinet SHINWHA V501-1 TAPE SGT-730 Details for DY551 (BLACK) and surrounding parts V501-2 SHINWHA TAPE SGT-730 B-11 L-10 (WHITE) DY551 L-10 Scotch Tape #880 B-20 L-13 CLN551 SP801 DY551 L-13 CRT CBA B-11 B-20 CLN801 DG691 B-20 Scotch Tape #880 V501 L-13 B-20...
  • Page 43 Packing TAPE PACKING TAPE PACKING TAPE 11-3 L2808PEX...

  • Page 44: Mechanical Parts List

    MECHANICAL PARTS LIST PRODUCT SAFETY NOTE: Products marked with a # Ref. No. Description Part No. have special characteristics important to safety. Before CRT TYPE A replacing any of these components, read carefully the DY551# DEFLECTION YOKE SCD-29319 LLBY00ZQS018 product safety notice in this service manual. Don't V501# CRT A68QCP693X TCRT190SM032...

  • Page 45: Electrical Parts List

    ELECTRICAL PARTS LIST PRODUCT SAFETY NOTE: Products marked with a Ref. No. Description Part No. # have special characteristics important to safety. PCB JUMPER D0.6-P5.0 JW5.0T Before replacing any of these components, read care- FILM CAP .(P) 0.047µF/50V J or CMA1JJS00473 fully the product safety notice in this service manual.
  • Page 46 Ref. No. Description Part No. Ref. No. Description Part No. C328 ELECTROLYTIC CAP . 10µF/50V M or CE1JMASTL100 ELECTROLYTIC CAP . 2.2µF/50V M CE1JMASDL2R2 ELECTROLYTIC CAP . 10µF/50V M CE1JMASDL100 C501 FILM CAP .(P) 0.22µF/100V J or CMA2AJS00224 C329 CERAMIC CAP .(AX) F Z 0.01µF/25V CDA1EZT0F103 FILM CAP(P) 0.22µF/100V J TF or CMB2AJS00224...
  • Page 47 Ref. No. Description Part No. Ref. No. Description Part No. ELECTROLYTIC CAP . 10µF/50V M CE1JMASDL100 ELECTROLYTIC CAP . 1000µF/10V M CE1AMASDL102 C596 CERAMIC CAP . B K 220pF/500V CCD2JKS0B221 C685 ELECTROLYTIC CAP . 100µF/10V M or CE1AMASTL101 C601# METALLIZED FILM CAP . 0.1µF/250V or CT2E104MS037 ELECTROLYTIC CAP .
  • Page 48 Ref. No. Description Part No. Ref. No. Description Part No. C833 ELECTROLYTIC CAP . 100µF/16V M or CE1CMASTL101 D582# FAST RECOVERY DIODE ERD38-06L AERD3806L000 ELECTROLYTIC CAP . 100µF/16V M CE1CMASDL101 D583 SWITCHING DIODE 1SS133(T-77) or QDTZ001SS133 CONNECTORS SWITCHING DIODE 1N4148 NDTZ001N4148 D584# SWITCHING DIODE 1SS133(T-77) or...
  • Page 49 Ref. No. Description Part No. Ref. No. Description Part No. D672 SWITCHING DIODE 1SS133(T-77) or QDTZ001SS133 LINE FILTER MS036 or LLBG00ZY2009 SWITCHING DIODE 1N4148 NDTZ001N4148 LINE FILTER CSA-LF032 LLBG00ZSA007 D675 SWITCHING DIODE 1SS133(T-77) or QDTZ001SS133 TRANSISTORS SWITCHING DIODE 1N4148 NDTZ001N4148 RES.
  • Page 50 Ref. No. Description Part No. Ref. No. Description Part No. TRANSISTOR 2SC2120-Y(TPE2) QQSY02SC2120 TRANSISTOR 2SC3331(U)-AANP or 2SC3331UZ Q652# TRANSISTOR 2SC2785(F) or QQSF02SC2785 TRANSISTOR 2SC1815-GR(TPE2) QQS102SC1815 TRANSISTOR 2SC2785(H) or QQSH02SC2785 Q792 TRANSISTOR 2SC2785(F) or QQSF02SC2785 TRANSISTOR 2SC2785(J) or QQSJ02SC2785 TRANSISTOR 2SC2785(H) or QQSH02SC2785 TRANSISTOR KTC3199(GR) or NQS10KTC3199...
  • Page 51 Ref. No. Description Part No. Ref. No. Description Part No. CHIP RES.(1608) 1/10W J 100 Ω CARBON RES. 1/4W J 3.3 Ω R121 RRXAJB5Z0101 R504 RCX4JATZ03R3 CHIP RES.(1608) 1/10W J 100 Ω CARBON RES. 1/4W J 1.8k Ω R122 RRXAJB5Z0101 R505 RCX4JATZ0182 CHIP RES.(1608) 1/10W J 1k Ω...
  • Page 52 Ref. No. Description Part No. Ref. No. Description Part No. CARBON RES. 1/4W J 15k Ω CARBON RES. 1/4W J 4.7k Ω R599# RCX4JATZ0153 R694 RCX4JATZ0472 CEMENT RES. 7W K 0.56 Ω or CARBON RES. 1/4W J 10 Ω R601# RW07R56DP007 R696 RCX4JATZ0100...
  • Page 53 Ref. No. Description Part No. Ref. No. Description Part No. CHIP RES.(1608) 1/10W J 10k Ω CHIP RES. 1/10W J 0 Ω R863 RRXAJB5Z0103 J120 RRXAJB5Z0000 CHIP RES. 1/10W J 0 Ω SWITCHES J135 RRXAJB5Z0000 CHIP RES. 1/10W J 0 Ω J180 RRXAJB5Z0000 SW101...
  • Page 54 Ref. No. Description Part No. Ref. No. Description Part No. X'TAL 3.579545MHz(30PPM) FXD355LCHE01 TRANSISTOR 2SC1815-GR(TPE2) QQS102SC1815 Q1532 TRANSISTOR 2SC5360 or QQ9Z02SC5360 TRANSISTOR 2SC4544 or QQ9Z02SC4544 CRT CBA TRANSISTOR KTC3229 NQ5Z0KTC3229 RESISTORS Ref. No. Description Part No. CARBON RES. 1/4W J 100 Ω R1501 RCX4JATZ0101 CRT CBA...
  • Page 55 CST274FE L2808CJ 2004-03-19...

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