Sharp 27SF560 Service Manual

sales service only. The contents are subject to change without notice. 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 should be used. COLOR TELEVISION Chassis No. GB-3D Page » ELECTRICAL SPECIFICATIONS .........................................................................................................1 » IMPORTANT SERVICE SAFETY PRECAUTION .................................................................................2 » LOCATION OF USER'S CONTROL .....................................................................................................5 » INSTALLATION AND SERVICE INSTRUCTIONS ................................................................................6 » SERVICE ADJUSTMENT ...................................................................................................................10 » CHASSIS LAYOUT .............................................................................................................................14 » BLOCK DIAGRAM ..............................................................................................................................15 » DESCRIPTION OF SCHEMATIC DIAGRAMS & WAVEFORMS ........................................................16 » SCHEMATIC DIAGRAMS ...................................................................................................................17 » PRINTED WIRING BOARD ASSEMBLIES ........................................................................................24 » PARTS LIST ........................................................................................................................................29 » PACKING OF THE SET ......................................................................................................................38 SPEAKER SIZE ........................................................ 12 x 6 cm oval (2 pcs.) VOICE COIL IMPEDANCE............................... 8 ohm at 400 Hz ANTENNA INPUT IMPEDANCE VHF/UHF .....................................................75 ohm Unbalanced TUNING RANGES VHF-Channels ...............................................................2 thru 13 UHF-Channels ............................................................14 thru 69 CATV Channels ...........................................................1 thru 125 Digital Terrestrial Broadcast (VHF/UHF) .......................2 thru 69 (EIA, Channel Plan U.S.A.) POWER INPUT ..................................................... 120V AC, 60 Hz POWER RATING .................................................................. 140W PICTURE SIZE ....................................... 2,193.5 cm2 (339sq inch) CONVERGENCE ............................................................. Magnetic SWEEP DEFLECTION .................................................... Magnetic FOCUS ............................................... Hi-Bi-Potential Electrostatic INTERMEDIATE FREQUENCIES Picture IF Carrier Frequency ...... 45.75 MHz (Analog Terrestrial) Sound IF Carrier Frequency ....... 41.25 MHz (Analog Terrestrial) Color Sub-Carrier Frequency ..... 42.17 MHz (Analog Terrestrial) IF Center Frequency ........................ 44 MHz (Digital Terrestrial) (Nominal) AUDIO POWER OUTPUT RATING .............. 5.0W + 5.0W (at 10% distortion and Dual CH Operate) Specifications are subject to change without prior notice. ELECTRICAL SPECIFICATIONS MODEL SERVICE MANUAL 27SF560 CONTENTS SY5Q927SF560/

Ë Service work should be performed only by qualified service technicians who are thoroughly familiar with all safety checks and the servicing guidelines which follow: CAUTION: FOR CONTINUED PROTECTION AGAINST A RISK OF FIRE, REPLACE ONLY WITH SAME TYPE 4A- 125V FUSE. X-RADIATION AND HIGH VOLTAGE LIMITS 1. Be sure all service personnel are aware of the procedures and instructions covering X-radiation. The only potential source of X-ray in current solid state TV receivers is the picture tube. However, the picture tube does not emit measurable X-Ray radiation, if the high voltage is as specified in the "High Voltage Check" instructions. It is only when high voltage is excessive that X- radiation is capable of penetrating the shell of the picture tube including the lead in the glass material. The important precaution is to keep the high voltage below the maximum level specified. 2. It is essential that servicemen have available at all times an accurate high voltage meter. The calibration of this meter should be checked periodically. 3. High voltage should always be kept at the rated value −no higher. Operation at higher voltages may cause a failure of the picture tube or high voltage circuitry and;also, under certain conditions, may produce radiation in exceeding of desirable levels. 4. When the high voltage regulator is operating properly there is no possibility of an X-radiation problem. Every time a color chassis is serviced, the brightness should be tested while monitoring the high voltage with a meter to be certain that the high voltage does not exceed the specified value and that it is regulating correctly. 5. Do not use a picture tube other than that specified or make unrecommended circuit modifications to the high voltage circuitry. 6. When trouble shooting and taking test measurements on a receiver with excessive high voltage, avoid being unnecessarily close to the receiver. Do not operate the receiver longer than is necessary to locate the cause of excessive voltage. WARNING 1. For continued safety, no modification of any circuit should be attempted. 2. Disconnect AC power before servicing. 3. Semiconductor heat sinks are potential shock hazards when the chassis is operating. 4. The chassis in this receiver has two ground systems which are separated by insulating material. The non- isolated (hot) ground system is for the B+ voltage regulator circuit. The isolated ground system is for the low B+ DC voltages and the secondary circuit of the high voltage transformer. To prevent electrical shock use an isolation transformer between the line cord and power receptacle, when servicing this chassis. SERVICING OF HIGH VOLTAGE SYSTEM AND PICTURE TUBE When servicing the high voltage system, remove the static charge by connecting a 10k ohm resistor in series with an insulated wire (such as a test probe) between the pic- ture tube ground and the 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 not lift picture tube by the neck. 4. Handle the picture tube only when wearing shatterproof goggles and after discharging the high voltage anode completely. 4A 125V

receivers have special safety-related characteristics. These characteristics are often not evident from visual inspection, nor can protection afforded by them be necessarily increased by using replacement components rated for higher voltage, wattage, etc. Replacement parts which have these special safety characteristics are identified in this manual; electrical components having such features are identified by "å" and shaded areas in the Replacement Parts Lists and Schematic Diagrams. IMPORTANT SERVICE SAFETY PRECAUTION (Continued) 1. Inspect all lead dress to make certain that leads are not pinched or that hardware is not lodged between the chassis and other metal parts in the receiver. 2. Inspect all protective devices such as non-metallic control knobs, insulating materials, cabinet backs, adjustment and compartment covers or shields, isolation resistor-capacity networks, mechanical insulators, etc. 3. To be sure that no shock hazard exists, check for leakage current in the following manner. • Plug the AC cord directly into a 120 volt AC outlet, (Do not use an isolation transformer for this test). • Using two clip leads, connect a 1.5k ohm, 10 watt resistor paralleled by a 0.15µF capacitor in series with all exposed metal cabinet parts and a known earth ground, such as electrical conduit or electrical ground connected to earth ground. • Use an AC voltmeter having with 5000 ohm per volt, or higher, sensitivity to measure the AC voltage drop across the resistor. BEFORE RETURNING THE RECEIVER (Fire & Shock Hazard) Before returning the receiver to the user, perform the following safety checks. • Connect the resistor connection to all exposed metal parts having a return to the chassis (antenna, metal cabinet, screw heads, knobs and control shafts, escutcheon, etc.) and measure the AC voltage drop across the resistor. AII checks must be repeated with the AC line cord plug connection reversed. (If necessary, a non- polarized adapter plug must be used only for the purpose of completing these check.) Any current measured must not exceed 0.5 milliamp. Any measurements not within the limits outlined above indicate of a potential shock hazard and corrective action must be taken before returning the instrument to the customer. For continued protection, replacement parts must be identical to those used in the original circuit. The use of substitute replacement parts which do not have the same safety characteristics as the factory recommended replacement parts shown in this service manual, may create shock, fire, X-radiation or other hazards. 1.5k ohm 10W 0.15µF TEST PROBE TO EXPOSED METAL PARTS CONNECT TO KNOWN EARTH GROUND

1 Employing lead-free solder "PWBs" of this model employs lead-free solder. The LF symbol indicates lead-free solder, and is attached on the PWBs and service manuals. The alphabetical character following LF shows the type of lead-free solder. Example: 2 Using lead-free wire solder When fixing the PWB soldered with the lead-free solder, apply lead-free wire solder. Repairing with conventional lead wire solder may cause damage or accident due to cracks. As the melting point of lead-free solder (Sn-Ag-Cu) is higher than the lead wire solder by 40°C, we recommend you to use a dedicated soldering bit, if you are not familiar with how to obtain lead-free wire solder or soldering bit, contact our service station or service branch in your area. 3 Soldering As the melting point of lead-free solder (Sn-Ag-Cu) is about 220°C which is higher than the conventional lead solder by 40°C, and as it has poor solder wettability, you may be apt to keep the soldering bit in contact with the PWB for extended period of time. However, since the land may be peeled off or the maximum heat-resistance temperature of parts may be exceeded, remove the bit from the PWB as soon as you confirm the steady soldering condition. Lead-free solder contains more tin, and the end of the soldering bit may be easily corroded. Make sure to turn on and off the power of the bit as required. If a different type of solder stays on the tip of the soldering bit, it is alloyed with lead-free solder. Clean the bit after every use of it. When the tip of the soldering bit is blackened during use, file it with steel wool or fine sandpaper. Be careful when replacing parts with polarity indication on the PWB silk. L F a Indicates lead-free solder of tin, silver and copper. Part No. ★ Description Code ZHNDAi123250E J φ0.3mm 250g(1roll) BL ZHNDAi126500E J φ0.6mm 500g(1roll) BK ZHNDAi12801KE J φ1.0mm 1kg(1roll) BM Lead-free wire solder for servicing

Front Panel POWER Press On. Press again Off. REMOTE CONTROL SENSOR MENU Press Accesses MAIN MENU. Press again Exits MAIN MENU. VOLUME UP/DOWN ( + ) Increases sound. ( – ) Decreases sound. CHANNEL UP/DOWN ( ) Selects next higher channel. ( ) Selects next lower channel. INSIDE DOOR VIDEO/AUDIO IN 2 TERMINALS Note: • The above shaded buttons on the Remote Control glow in the dark. To use the glow-in-the-dark display on the remote control, place it under a fluorescent light or other lighting. • The phosphorescent material contains no radioactive or toxic material, so it is safe to use. • The degree of illumination will vary depending on the strength of lighting used. • The degree of illumination will decrease with time and depending on the temperature. • The time needed to charge the phosphorescent display will vary depending on the surrounding lighting. • Sunlight and fluorescent lighting are the most effective when charging the display. • The TV set and remote control illustrations and the on-screen displays in this manual may differ from their actual appearance. 1 2 3 4 5 6 7 8 9 0 POWER TV MENU MUTE PAUSE FLASHBACK DISPLAY INPUT TV CATV VCR DVD STOP REC REW PLAY FF CH/SKIP VOL ó CH CH VOL + ENTER A B C D PERSONAL PREFERENCE DVD VCR CATV TV DVD VCR POWER Press On. Press again Off. REMOTE KEYPAD (0 - 9) Sets the channel. FLASHBACK Returns to previous channel. • (DOT) Sets the channel. PERSONAL PREFERENCE With the Personal Preference buttons, you can program your favorite programs by using the 4 categories A, B, C and D. The channels can be accessed quickly by using these buttons. VOLUME UP/DOWN ( + ) Increases sound. ( – ) Decreases sound. • Changes or selects the TV adjustments on On-Screen Display. MENU Press Accesses MAIN MENU. Press again Exits MAIN MENU. CATV/DVD-TV/VCR MODE SELECT SWITCH In TV/VCR position, signals sent will be for TV and VCR control. In CATV/DVD position, signals sent will be for cable TV converter and DVD control. DVD/VCR CONTROL Infrared Transmitter Window DISPLAY Press Displays receiving channel for 4 seconds. Press again Removes display. • Temporarily displays receiving channel when in Closed Caption mode. INPUT Press Switches to external video INPUT 1 mode. Press twice Switches to external video INPUT 2 mode. Press 3 times Switches to external video INPUT 3 mode or COMPONENT mode. Press 4 times Switches back to the original TV mode. ENTER • Used to confirm the channel selection and Personal Preference channel. • Used in some instances where a Cable Converter Box requires an “enter” command after selecting channels, when using the REMOTE KEYPAD button. CHANNEL UP/DOWN ( ) Selects next higher channel. ( ) Selects next lower channel. • Moves the “ æ ” mark on the MENU screens. MUTE Press Mutes sound. Press again Restores sound. Basic Remote Control Functions