LG-LHC6231-hcs-sm 电路图 维修手册.pdf

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1、DVD/CD/VCR RECEIVER Home Cinema System SERVICE MANUAL MODELS: 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, 2003 SERVICE MANUALMODELS : LH-C6230P/C6231P/LH-C6230S/LH-C

2、6230W/LH-C6231W/LH-C6230X/LH-C6230Y/C6231Y RadioFans.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 .1-7 SECTION 2. AUDIO PART AMP ELECTRICAL TROUBLESHOOTING GUDIE.2-1 BLOCK DIAGRAM

3、. 2-2 AUDIO SCHEMATIC DIAGRAMS .2-4 WIRING DIAGRAM.2-10 AUDIO VOLTAGE SHEET (IC CONNECT A 1500 OHM 10 WATT RESIS- TOR, PARALLELED BY A .15 MFD. 150.V A.C TYPE CAPACITOR BETWEEN A KNOWN GOOD EARTH GROUND (WATER PIPE, CON- DUIT, ETC.) AND THE EXPOSED METALLIC PARTS, ONE AT A TIME. MEASURE THE A.C. VOL

4、TAGE ACROSS THE COMBINATION OF 1500 OHM RESISTOR AND .15 MFD CAPACITOR. REVERSE THE A.C. PLUG AND REPEAT A.C. VOLTAGE MEASUREMENTS FOR EACH EXPOSED METALLIC PART. VOLTAGE MEASURED MUST NOT EXCEED 75 VOLTS R.M.S. THIS CORRESPONDS TO 0.5 MILLIAMP A.C ANY VALUE EXCEEDING THIS LIMIT CONSTITUTES A POTENT

5、IAL SHOCK HAZARD AND MUST BE CORRECTED IMMEDIATELY. SUBJECT: GRAPHIC SYMBOLS THE LIGHTNING FLASH WITH APROWHEAD SYMBOL. WITHIN AN EQUILATERAL TRIANGLE, IS INTENDED TO ALERT THE SERVICE PERSONNEL TO THE PRESENCE OF UNINSULATED DANGEROUS VOLTAGE THAT MAY BE OF SUFFICIENT MAG- NITUDE TO CONSTITUTE A RI

6、SK OF ELECTRIC SHOCK. THE EXCLAMATION POINT WITHIN AN EQUILATERAL TRIAN- GLE IS INTENDED TO ALERT THE SERVICE PERSONNEL TO THE PRESENCE OF IMPORTANT SAFETY INFORMATION IN SERVICE LITERATURE. SUBJECT : X-RADIATION 1. BE SURE PROCEDURES AND INSTRUCTIONS TO ALL SERVICE PER- SONNEL COVER THE SUBJECT OF

7、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 WHEN THE 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 FAILU

8、RE 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 BE USED. DEGAUSSING SHIELDS ALSO SERVE AS X-RAY SHIELD IN COLOR SETS, ALWAYS RE-INSTALL THEM. 3. IT IS ESS

9、NTIAL THAT SERVICE PERSONNEL HAVE AVAILABLE AN ACCURATE AND RELIABLE HIGH VOLTAGE METER. THE CALIBRA TION OF THE METER SHOULD BE CHECKED PERIODICALLY AGAINST A REFERENCE STANDARD, SUCH AS THE ONE AVAILABLE AT YOUR DISTRIBUTOR. 4. WHEN THE HIGH VOLTAGE CIRCUITRY IS OPERATING PROPERLY THERE IS NO POSS

10、IBILITY OF AN X-RADIATION PROBLEM. EVERY TIME A COLOR CHASSIS IS SERVICED. THE BRIGHTNESS SHOULD BE RUN UP AND DOWN 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, WE SUGGEST THAT YOU AND YOUR

11、 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 ON EACH CUSTOMER S INVOICE. 5. WHEN TROUBLESHOOTING AND MAKING TEST MEASUREMENTS IN A PRODUCT WITH A PROBLEM OF EXCESSIVE H

12、IGH VOLTAGE, AVOID BEING UNNECESSARILY CLOSE TO THE PICTURE TUBE AND THE HIGH VOLTAGE SUPPLY. DO NOT OPERATE THE PRODUCT LONGER THAN IS NECESSARY TO LOCATE THE CAUSE OF EXCES SIVE VOLTAGE. 6. REFER TO HV. B+ AND SHUTDOWN ADJUSTMENT PROCEDURES DESCRIBED IN THE APPROPRIATE SCHEMATIC AND DIAGRAMS (WHER

13、E USED). SUBJECT: IMPLOSION 1. ALL DIRECT VIEWED PICTURE TUBES ARE EQUIPPED WITH AN INTE GRAL IMPLOSION PROTECTION SYSTEM, BUT CARE SHOULD BE TAKEN TO AVOID DAMAGE DURING INSTALLATION, AVOID SCRATCHING THE TUBE. IF SCRATCHED REPLACE IT. 2. USE ONLY RECOMMENDED FACTORY REPLACEMENT TUBES. SUBJECT : TI

14、PS ON PROPER INSTALLATION 1. NEVER INSTALL ANY PRODUCT IN A CLOSED-IN RECESS, CUBBY- HOLE OR CLOSELY FITTING SHELF SPACE. OVER OR CLOSE TO HEAT DUCT, OR IN THE PATH OF HEATED AIR FLOW. 2. AVOID CONDITIONS OF HIGH HUMIDITY SUCH AS: OUTDOOR PATIO INSTALLATIONS WHERE DEW IS A FACTOR, NEAR STEAM RADIA-

15、TORS WHERE STEAM LEAKAGE IS A FACTOR, ETC. 3. AVOID PALCEMENT WHERE DRAPERIES MAY OBSTRUCT REAR VENTING. THE CUSTOMER SHOULD ALSO AVOID THE USE OF DEC- ORATIVE SCARVES OR OTHER COVERINGS WHICH MIGHT OBSTRUCT VENTILATION. 4. WALL AND SHELF MOUNTED INSTALLATIONS USING A COMMER- CIAL MOUNTING KIT. MUST

16、 FOLLOW THE FACTORY APPROVED MOUNTING INSTRUCTIONS A PRODUCT MOUNTED TO A SHELF OR PLATFORM MUST RETAIN ITS ORIGINAL FEET (OR THE EQUIVALENT THICKNESS IN SPACERS) TO PROVIDE ADEQUATE AIR FLOW ACROSS THE BOTTOM, BOLTS OR SCREWS USED FOR FASTENERS MUST NOT TOUCH ANY PARTS OR WIRING. PERFORM LEAKAGE TE

17、ST ON CUSTOMIZED INSTALLATIONS. 5. CAUTION CUSTOMERS AGAINST THE MOUNTING OF A PRODUCT ON SLOPING SHELF OR A TILTED POSITION, UNLESS THE PRODUCT IS PROPERLY SECURED. 6. A PRODUCT ON A ROLL-ABOUT CART SHOULD BE STABLE ON ITS MOUNTING TO THE CART. CAUTION THE CUSTOMER ON THE HAZ- ARDS OF TRYING TO ROL

18、L A CART WITH SMALL CASTERS ACROSS THRESHOLDS OR DEEP PILE CARPETS. 7. CAUTION CUSTOMERS AGAINST THE USE OF A CART OR STAND WHICH 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 OF THE SAME OR

19、 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 TO HOME AND FAMILY. PRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRODUCTS A.C. VOLTMETER GOOD EARTH GROUND SUCH AS T

20、HE WATER PIPE. CONDUIT. ETC PLACE THIS PROBE ON EACH EXPOSED METAL PART RadioFans.CN 收音机爱 好者资料库 NOTES REGARDING HANDLING OF THE PICK-UP 1. Notes for transport and storage 1) The pick-up should always be left in its conductive bag until immediately prior to use. 2) The pick-up should never be subject

21、ed to external pressure or impact. 2. Repair notes 1) 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 and impact. If it is subjected to strong

22、 pressure or impact, the result may be an operational malfunction and/or damage to the printed-circuit board. 3) Each and every pick-up is already individually adjusted to a high degree of precision, and for that reason the adjustment point and installation screws should absolutely never be touched.

23、 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 surface If there is dust on the lens surface, the dust should be cleaned away by usin

24、g an air bush (such as used for camera lens). The lens is held by a delicate spring. When cleaning the lens surface, therefore, a cotton 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

25、 isopropyl alcohol to the cotton swab. (Do not use any other liquid cleaners, because they will damage the lens.) Take care not to use too much of this alcohol on the swab, and do not allow the alcohol to get inside the pick-up. - 1-3 - Storage in conductive bagDrop impact NEVER look directly at the

26、 laser beam, and dont let contact fingers or other exposed skin. Magnet How to hold the pick-up Pressure Pressure Cotton swab Conductive Sheet - 1-4 - NOTES REGARDING COMPACT DISC PLAYER REPAIRS 1. Preparations 1) Compact disc players incorporate a great many ICs as well as the pick-up (laser diode)

27、. These components are sensitive to, and easily affected by, static electricity. If such static electricity is high voltage, 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 component

28、s. Care must be taken, therefore, to avoid repair or storage where the temperature of humidity is high, where strong magnetism is present, or where there is excessive dust. 2. Notes for repair 1) Before replacing a component part, first disconnect the power supply lead wire from the unit 2) All equi

29、pment, 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 is because there is the possibility of damage by static electricity.)

30、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 prevent static electricity changes in the clothing to escape from

31、the armband. 7) The laser beam from the pick-up should NEVER be directly facing the eyes or bare skin. Armband Conductive Sheet Resistor (1 Mohm) Resistor (1 Mohm) - 1-5 - SERVICING PRECAUTIONS CAUTION : Before servicing the COMBI HOME THEATER SYSTEM covered by this service data and its supplements

32、and addends, read and follow the SAFETY PRECAUTIONS. NOTE : if unforeseen circumstances create conflict between the following servicing precautions and any of the safety pre- cautions in this publications, always follow the safety pre- cautions. Remembers Safety First: General Servicing Precautions

33、1. Always unplug the COMBI HOME THEATER SYSTEM AC power 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 electrical plug or other electrical connection. (3)Connecting a test su

34、bstitute in parallel with an elec- trolytic capacitor. Caution : A wrong part substitution or incorrect polarity installation of electrolytic capacitors may result in an explosion hazard. 2. Do not spray chemicals on or near this COMBI HOME THEATER SYSTEM or any of its assemblies. 3. Unless specifie

35、d otherwise in this service data, clean electrical 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, lubrication of contacts is not required. 4. Do not

36、 defeat any plug/socket B+ voltage interlocks with whitch instruments covered by this service manual might be equipped. 5. Do not apply AC power to this COMBI HOME THEATER SYSTEM and/or any of its electrical assemblies unless all solid-state device heat sinks are cerrectly installed. 6. Always conne

37、ct test instrument ground lead to the appropriate ground before connection the test instrument positive lead. Always remove the test instrument ground lead last. Insulation Checking Procedure Disconnect the attachment plug from the AC outlet and turn the power on. Connect an insulation resistance me

38、ter(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. Electrost

39、atically Sensitive (ES) Devices Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components commonly are called Electrostatically Sensitive (ES) Devices. Examples of typical ES devices are integrated circuits and some field effect transistors and semiconduct

40、or chip components. The following techniques should be used to help reduce the incidence of component damage caused by static electricity. 1. Immediately before handling any semiconductor compo- nent or semiconductor-equipped assembly, drain off any electrostatic charge on your body by touching a kn

41、own earth 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 electrical assembly equipped with ES devices, place the assembly on a c

42、onductive surface such as aluminum foil, to prevent electrostatic charge buildup or exposure of the assembly. 3. Use only a grouned-tip soldering iron to solder or unsolder ES devices. 4. Use only an anti-static solder removal device. Some solder removal devices not classified a anti-static can gene

43、rate electrical charges sufficient to damage ES devices. 5. Do not use freon-propelled chemicals. These can generate electrical charge sufficient to damage ES devices. 6. Do not remove a replacement ES device from its protec tive package until immediately before you are ready to install it. (Most re

44、placement ES devices are packaged with leads electrically shorted together by conductive foam, aluminum foil, or comparable conductive material). 7. Immediately before removing the protective material from the leads of a replacement ES device, touch the protective material to the chassis or circuit

45、assembly into which the device will be installed. Caution : Be sure no power is applied to the chassis or circuit, and observe all other safety precautions. 8. Minimize bodily motions when handling unpackaged replacement ES devices. (Normally harmless motion such as the brushing together of your clo

46、thes fabric or the lifting of your foot from a carpeted floor can generate static elec- tricity sufficient to damage an ES device.) - 1-6 - ESD PRECAUTIONS Electrostatically Sensitive Devices (ESD) Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components

47、commonly are called Electrostatically Sensitive Devices (ESD). Examples of typical ESD devices are integrated circuits and some field-effect transistors and semiconductor chip components. The following techniques should be used to help reduce the incidence of component damage caused by static electricity. 1. Immediately before handling any semiconductor component or semiconductor-equipped assembly, drain off any electrostatic