LG-LHC6231-hcs-sm 维修电路原理图.pdf

DVD/CD/VCR RECEIVERHome Cinema SystemSERVICE MANUALMODELS: LH-C6230P/C6231P (LGEDG/LGEES/LGEPT/LGEIS)LH-C6230S (LGEFS/STUH)LH-C6230W (LGESA/LGEGF)LH-C6231W (LGEAP)LH-C6230X (MOSCOW)LH-C6230Y/C6231Y (LGEPL/LGEMK)P/N : 3829RDT033CJULY, 2003SERVICE MANUALMODELS : LH-C6230P/C6231P/LH-C6230S/LH-C6230W/LH-C6231W/LH-C6230X/LH-C6230Y/C6231YRadioFans.CN 收音机爱 好者资料库- 1-1 -SECTION 1. GENERAL PRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRECAUTIONS .1-2 SERVICING PRECAUTIONS. 1-5 ESD PRECAUTIONS.1-6 SPECIFICATIONS .1-7SECTION 2. AUDIO PART AMP ELECTRICAL TROUBLESHOOTING GUDIE.2-1 BLOCK DIAGRAM. 2-2 AUDIO SCHEMATIC DIAGRAMS .2-4 WIRING DIAGRAM.2-10 AUDIO VOLTAGE SHEET (IC&TR). 2-12 PRINTED CIRCUIT DIAGRAM . 2-14SECTION 3. VCR PART ELECTRICAL ADJUSTMENT PROCEDURES .3-1 VCR ELECTRICAL TROUBLESHOOTING.3-2 VCR SHEMATIC DIAGRAMS. 3-17 VCR VOLTAGE SHEET (IC&TR). 3-29 PRINTED CIRCUIT DIAGRAMS. 3-31SECTION 4. MECHANSIM OF VCR PART.4-1SECTION 5. DVD PART DVD ELECTRICAL TROUBLESHOOTING. 5-1 DETAILS AND WAVEFORMS ON SYSTEM TEST AND DEBUGGING . 5-7 DVD PART SCHEMATIC DIAGRAMS. 5-21 VOLTAGE SHEET (IC&TR) . 5-29 PRINTED CIRCUIT DIAGRAM . 5-31SECTION 6. MECHANSIM OF DVD PART.6-1SECTION 7. EXPLODED VIEWS PART.7-1 Cabinet and Main frame. 7-1 Speaker . 7-3SECTION 8. REPLACEMENT PARTS LIST.8-1CONTENTSRadioFans.CN 收音机爱 好者资料库- 1-2 -SECTION 1. GENERAL PARTCAUTION : DO NOT ATTEMPT TO MODIFY THIS PRODUCT IN ANY WAY,NEVER PERFORM CUSTOMIZED INSTALLATIONS WITHOUT MANUFAC-TURER S APPROVAL. UNAUTHORIZED MODIFICATIONS WILL NOT ONLYVOID THE WARRANTY, BUT MAY LEAD TO YOUR BEING LIABLE FOR ANYRESULTING PROPERTY DAMAGE OR USER INJURY.SERVICE WORK SHOULD BE PERFORMED ONLY AFTER YOU ARETHOROUGHLY FAMILIAR WITH ALL OF THE FOLLOWING SAFETYCHECKS AND SERVICING GUIDELINES. TO DO OTHERWISE,INCREASES THE RISK OF POTENTIAL HAZARDS AND INJURY TO THEUSER.WHILE SERVICING, USE AN ISOLATION TRANSFORMER FOR PROTEC-TION FROM A.C. LINE SHOCK.SAFETY CHECKSAFTER THE ORIGINAL SERVICE PROBLEM HAS BEEN CORRCTED. ACHECK SHOULD BE MADE OF THE FOLLOWING.SUBJECT : FIRE & SHOCK HAZARD1. BE SURE THAT ALL COMPONENTS ARE POSITIONED IN SUCH A WAYAS TO AVOID POSSIBILITY OF ADJACENT COMPONENT SHORTS.THIS IS ESPECIALLY IMPORTANT ON THOSE MODULES WHICH ARETRANSPORTED TO AND FROM THE REPAIR SHOP.2. NEVER RELEASE A REPAIR UNLESS ALL PROTECTIVE DEVICESSUCH AS INSULATORS, BARRIERS, COVERS, SHIELDS, STRAIN RELIEFS, POWER SUPPLY CORDS, AND OTHER HARDWARE HAVEBEEN REINSTALLED PER ORIGINAL DESIGN. BE SURE THAT THESAFETY PURPOSE OF THE POLARIZED LINE PLUG HAS NOT BEENDEFEATED.3. SOLDERING MUST BE INSPECTED TO DISCOVER POSSIBLE COLDSOLDER JOINTS, SOLDER SPLASHES OR SHARP SOLDER POINTS.BE CERTAIN TO REMOVE ALL LOOSE FOREIGN PARTICLES.4. CHECK FOR PHYSICAL EVIDENCE OF DAMAGE OR DETERIORATIONTO PARTS AND COMPONENTS. FOR FRAYED LEADS, DAMAGEDINSULATION (INCLUDING A.C. CORD). AND REPLACE IF NECESSARYFOLLOW ORIGINAL LAYOUT, LEAD LENGTH AND DRESS.5. NO LEAD OR COMPONENT SHOULD TOUCH A RECIVING TUBE ORA RESISTOR RATED AT 1 WATT OR MORE. LEAD TENSION AROUNDPROTRUNING METAL SURFACES MUST BE AVOIDED.6. ALL CRITICAL COMPONENTS SUCH AS FUSES, FLAMEPROOFRESISTORS, CAPACITORS, ETC. MUST BE REPLACED WITH EXACTFACTORY TYPES, DO NOT USE REPLACEMENT COMPONENTSOTHER THAN THOSE SPECIFIED OR MAKE UNRECOMMENDED CIR-CUIT MODIFICATIONS.7. AFTER RE-ASSEMBLY OF THE SET ALWAYS PERFORM AN A.C.LEAKAGE TEST ON ALL EXPOSED METALLIC PARTS OF THE CABI-NET, (THE CHANNEL SELECTOR KNOB, ANTENNA TERMINALS. HAN-DLE AND SCREWS) TO BE SURE THE SET IS SAFE TO OPERATEWITHOUT DANGER OF ELECTRICAL SHOCK. DO NOT USE A LINE ISOLATION TRANSFORMER DURING THIS TEST USE AN A.C. VOLT-METER, HAVING 5000 OHMS PER VOLT OR MORE SENSITIVITY, INTHE FOLLOWING MANNER; CONNECT A 1500 OHM 10 WATT RESIS-TOR, PARALLELED BY A .15 MFD. 150.V A.C TYPE CAPACITORBETWEEN A KNOWN GOOD EARTH GROUND (WATER PIPE, CON-DUIT, ETC.) AND THE EXPOSED METALLIC PARTS, ONE AT A TIME.MEASURE THE A.C. VOLTAGE ACROSS THE COMBINATION OF 1500 OHM RESISTOR AND .15 MFD CAPACITOR. REVERSE THE A.C. PLUGAND REPEAT A.C. VOLTAGE MEASUREMENTS FOR EACH EXPOSED METALLIC PART. VOLTAGE MEASURED MUST NOT EXCEED 75VOLTS R.M.S. THIS CORRESPONDS TO 0.5 MILLIAMP A.C ANYVALUE EXCEEDING THIS LIMIT CONSTITUTES A POTENTIAL SHOCKHAZARD AND MUST BE CORRECTED IMMEDIATELY.SUBJECT: GRAPHIC SYMBOLSTHE LIGHTNING FLASH WITH APROWHEAD SYMBOL. WITHINAN EQUILATERAL TRIANGLE, IS INTENDED TO ALERT THESERVICE PERSONNEL TO THE PRESENCE OF UNINSULATEDDANGEROUS VOLTAGE THAT MAY BE OF SUFFICIENT MAG-NITUDE TO CONSTITUTE A RISK OF ELECTRIC SHOCK.THE EXCLAMATION POINT WITHIN AN EQUILATERAL TRIAN-GLE IS INTENDED TO ALERT THE SERVICE PERSONNEL TOTHE PRESENCE OF IMPORTANT SAFETY INFORMATION INSERVICE LITERATURE.SUBJECT : X-RADIATION1. BE SURE PROCEDURES AND INSTRUCTIONS TO ALL SERVICE PER-SONNEL COVER THE SUBJECT OF X-RADIATION. THE ONLY POTEN-TIAL SOURCE OF X-RAYS IN CURRENT T.V. RECEIVERS IS THE PIC-TURE TUBE. HOWEVER, THIS TUBE DOES NOT EMIT X-RAYS WHENTHE HIGH VOLTAGE IS AT THE FACTORY SPECIFIED LEVEL. THE PROPER VALUE IS GIVEN IN THE APPLICABLE SCHEMATIC. OPERA-TION AT HIGHER VOLTAGES MAY CAUSE A FAILURE OF THE PIC-TURE TUBE OR HIGH VOLTAGE SUPPLY AND, UNDER CERTAIN CIR-CUMSTANCES, MAY PRODUCE RADIATION IN EXCESS OF DESIR-ABLE LEVELS.2. ONLY FACTORY SPECIFIED C.R.T. ANODE CONNECTORS MUST BEUSED. DEGAUSSING SHIELDS ALSO SERVE AS X-RAY SHIELD INCOLOR SETS, ALWAYS RE-INSTALL THEM.3. IT IS ESSNTIAL THAT SERVICE PERSONNEL HAVE AVAILABLE ANACCURATE AND RELIABLE HIGH VOLTAGE METER. THE CALIBRATION OF THE METER SHOULD BE CHECKED PERIODICALLYAGAINST A REFERENCE STANDARD, SUCH AS THE ONE AVAILABLEAT YOUR DISTRIBUTOR.4. WHEN THE HIGH VOLTAGE CIRCUITRY IS OPERATING PROPERLYTHERE IS NO POSSIBILITY OF AN X-RADIATION PROBLEM. EVERYTIME A COLOR CHASSIS IS SERVICED. THE BRIGHTNESS SHOULDBE RUN UP AND DOWN WHILE MONITORING THE HIGH VOLTAGEWITH A METER TO BE CERTAIN THAT THE HIGH VOLTAGE DOESNOT EXCEED THE SPECIFIED VALUE AND THAT IT IS REGULATINGCORRECTLY, WE SUGGEST THAT YOU AND YOUR SERVICE ORGA-NIZATION REVIEW TEST PROCEDURES SO THAT VOLTAGE REGU-LATION IS ALWAYS CHECKED AS A STANDARD SERVICING PROCE-DURE. AND THAT THE HIGH VOLTAGE READING BE RECORDER ONEACH CUSTOMER S INVOICE.5. WHEN TROUBLESHOOTING AND MAKING TEST MEASUREMENTS INA PRODUCT WITH A PROBLEM OF EXCESSIVE HIGH VOLTAGE,AVOID BEING UNNECESSARILY CLOSE TO THE PICTURE TUBE ANDTHE HIGH VOLTAGE SUPPLY. DO NOT OPERATE THE PRODUCTLONGER THAN IS NECESSARY TO LOCATE THE CAUSE OF EXCESSIVE VOLTAGE.6. REFER TO HV. B+ AND SHUTDOWN ADJUSTMENT PROCEDURES DESCRIBED IN THE APPROPRIATE SCHEMATIC AND DIAGRAMS(WHERE USED).SUBJECT: IMPLOSION1. ALL DIRECT VIEWED PICTURE TUBES ARE EQUIPPED WITH AN INTEGRAL IMPLOSION PROTECTION SYSTEM, BUT CARE SHOULD BETAKEN TO AVOID DAMAGE DURING INSTALLATION, AVOIDSCRATCHING THE TUBE. IF SCRATCHED REPLACE IT.2. USE ONLY RECOMMENDED FACTORY REPLACEMENT TUBES.SUBJECT : TIPS ON PROPER INSTALLATION1. NEVER INSTALL ANY PRODUCT IN A CLOSED-IN RECESS, CUBBY-HOLE OR CLOSELY FITTING SHELF SPACE. OVER OR CLOSE TOHEAT DUCT, OR IN THE PATH OF HEATED AIR FLOW.2. AVOID CONDITIONS OF HIGH HUMIDITY SUCH AS: OUTDOOR PATIOINSTALLATIONS WHERE DEW IS A FACTOR, NEAR STEAM RADIA-TORS WHERE STEAM LEAKAGE IS A FACTOR, ETC.3. AVOID PALCEMENT WHERE DRAPERIES MAY OBSTRUCT REARVENTING. THE CUSTOMER SHOULD ALSO AVOID THE USE OF DEC-ORATIVE SCARVES OR OTHER COVERINGS WHICH MIGHTOBSTRUCT VENTILATION.4. WALL AND SHELF MOUNTED INSTALLATIONS USING A COMMER-CIAL MOUNTING KIT. MUST FOLLOW THE FACTORY APPROVED MOUNTING INSTRUCTIONS A PRODUCT MOUNTED TO A SHELF ORPLATFORM MUST RETAIN ITS ORIGINAL FEET (OR THE EQUIVALENTTHICKNESS IN SPACERS) TO PROVIDE ADEQUATE AIR FLOW ACROSS THE BOTTOM, BOLTS OR SCREWS USED FOR FASTENERSMUST NOT TOUCH ANY PARTS OR WIRING. PERFORM LEAKAGETEST ON CUSTOMIZED INSTALLATIONS.5. CAUTION CUSTOMERS AGAINST THE MOUNTING OF A PRODUCT ONSLOPING SHELF OR A TILTED POSITION, UNLESS THE PRODUCT ISPROPERLY SECURED.6. A PRODUCT ON A ROLL-ABOUT CART SHOULD BE STABLE ON ITSMOUNTING TO THE CART. CAUTION THE CUSTOMER ON THE HAZ-ARDS OF TRYING TO ROLL A CART WITH SMALL CASTERS ACROSSTHRESHOLDS OR DEEP PILE CARPETS.7. CAUTION CUSTOMERS AGAINST THE USE OF A CART OR STANDWHICH HAS NOT BEEN LISTED BY UNDERWRITERS LABORATORIES, INC. FOR USE WITH THEIR SPECIFIC MODEL OF TELEVISION RECEIVER OR GENERICALLY APPROVED FOR USE WITH T.V. S OFTHE SAME OR LARGER SCREEN SIZE.8. CAUTION CUSTOMERS AGAINST THE USE OF EXTENSION CORDS, EXPLAIN THAT A FOREST OF EXTENSIONS SPROUTING FROM A SIN-GLE OUTLET CAN LEAD TO DISASTROUS CONSEQUENCES TOHOME AND FAMILY.PRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRODUCTSA.C. VOLTMETERGOOD EARTH GROUNDSUCH AS THE WATERPIPE. CONDUIT. ETCPLACE THIS PROBEON EACH EXPOSEDMETAL PARTNOTES REGARDING HANDLING OF THE PICK-UP1. Notes for transport and storage1) The pick-up should always be left in its conductive bag until immediately prior to use.2) The pick-up should never be subjected to external pressure or impact.2. Repair notes1) The pick-up incorporates a strong magnet, and so should never be brought close to magnetic materials.2) The pick-up should always be handled correctly and carefully, taking care to avoid external pressure andimpact. If it is subjected to strong pressure or impact, the result may be an operational malfunction and/ordamage to the printed-circuit board.3) Each and every pick-up is already individually adjusted to a high degree of precision, and for that reasonthe adjustment point and installation screws should absolutely never be touched.4) Laser beams may damage the eyes!Absolutely never permit laser beams to enter the eyes!Also NEVER switch ON the power to the laser output part (lens, etc.) of the pick-up if it is damaged.5) Cleaning the lens surfaceIf there is dust on the lens surface, the dust should be cleaned away by using an air bush (such as usedfor camera lens). The lens is held by a delicate spring. When cleaning the lens surface, therefore, acotton swab should be used, taking care not to distort this.6) Never attempt to disassemble the pick-up.Spring by excess pressure. If the lens is extremely dirty, apply isopropyl alcohol to the cotton swab. (Donot use any other liquid cleaners, because they will damage the lens.) Take care not to use too much ofthis alcohol on the swab, and do not allow the alcohol to get inside the pick-up.- 1-3 -Storage in conductive bagDrop impactNEVER look directly at the laser beam, and dont letcontact fingers or other exposed skin.MagnetHow to hold the pick-upPressurePressureCotton swabConductive Sheet- 1-4 -NOTES REGARDING COMPACT DISC PLAYER REPAIRS 1. Preparations1) Compact disc players incorporate a great many ICs as well as the pick-up (laser diode). Thesecomponents are sensitive to, and easily affected by, static electricity. If such static electricity is highvoltage, components can be damaged, and for that reason components should be handled with care.2) The pick-up is composed of many optical components and other high-precision components. Care mustbe taken, therefore, to avoid repair or storage where the temperature of humidity is high, where strongmagnetism is present, or where there is excessive dust.2. Notes for repair1) Before replacing a component part, first disconnect the power supply lead wire from the unit2) All equipment, measuring instruments and tools must be grounded.3) The workbench should be covered with a conductive sheet and grounded.When removing the laser pick-up from its conductive bag, do not place the pick-up on the bag. (This isbecause there is the possibility of damage by static electricity.)4) To prevent AC leakage, the metal part of the soldering iron should be grounded.5) Workers should be grounded by an armband (1M)6) Care should be taken not to permit the laser pick-up to come in contact with clothing, in order to preventstatic electricity changes in the clothing to escape from the armband.7) The laser beam from the pick-up should NEVER be directly facing the eyes or bare skin.ArmbandConductiveSheetResistor(1 Mohm)Resistor(1 Mohm)- 1-5 -SERVICING PRECAUTIONSCAUTION : Before servicing the COMBI HOME THEATERSYSTEM covered by this service data and its supplementsand addends, read and follow the SAFETY PRECAUTIONS.NOTE : if unforeseen circumstances create conflict betweenthe following servicing precautions and any of the safety pre-cautions in this publications, always follow the safety pre-cautions.Remembers Safety First:General Servicing Precautions1. Always unplug the COMBI HOME THEATER SYSTEM ACpower cord from the AC power source before:(1)Removing or reinstalling any component, circuit board, module, or any other assembly.(2)Disconnection or reconnecting any internal electricalplug or other electrical connection.(3)Connecting a test substitute in parallel with an elec-trolytic capacitor.Caution : A wrong part substitution or incorrect polarity installation of electrolytic capacitors may resultin an explosion hazard.2. Do not spray chemicals on or near this COMBI HOMETHEATER SYSTEM or any of its assemblies.3. Unless specified otherwise in this service data, cleanelectrical contacts by applying an appropriate contact cleaning solution to the contacts with a pipe cleaner,cotton-tipped swab, or comparable soft applicator.Unless specified otherwise in this service data, lubricationof contacts is not required.4. Do not defeat any plug/socket B+ voltage interlocks withwhitch instruments covered by this service manual mightbe equipped.5. Do not apply AC power to this COMBI HOME THEATERSYSTEM and/or any of its electrical assemblies unless allsolid-state device heat sinks are cerrectly installed.6. Always connect test instrument ground lead to theappropriate ground before connection the test instrumentpositive lead. Always remove the test instrument ground lead last.Insulation Checking ProcedureDisconnect the attachment plug from the AC outlet and turnthe power on. Connect an insulation resistance meter(500V)to the blades of the attachment plug. The insulation resis-tance between each blade of the attachment plug and acces-sible conductive parts (Note 1) should be more than 1M-ohm.Note 1 : Accessible Conductive Parts including Metal pan-els, Input terminals, Earphone jacks, etc.Electrostatically Sensitive (ES) DevicesSome semiconductor (solid state) devices can be damagedeasily by static electricity. Such components commonly arecalled Electrostatically Sensitive (ES) Devices. Examples oftypical ES devices are integrated circuits and some fieldeffect transistors and semiconductor chip components.The following techniques should be used to help reduce theincidence of component damage caused by static electricity.1. Immediately before handling any semiconductor compo-nent or semiconductor-equipped assembly, drain off anyelectrostatic charge on your body by touching a knownearth ground. Alternatively, obtain and wear a commer-cially available discharging wrist strap device, which should be removed for potential shock reasons prior to applying power to the unit under test.2. After removing an ele