LG-LHCX246-crs-sm 维修电路原理图.pdf

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1、DVD/VCR COMBI RECEIVERCombi Receiver SystemSERVICE MANUALMODELS : LH-CX245(LH-CX245X)/LH-CX246(LH-CX246X)LH-CX247(LH-CX247X)/LH-CX640(LH-CX640X)CAUTIONBEFORE SERVICING THE UNIT, READ THE “SAFETYPRECAUTIONS”IN THIS MANUAL.LH-CX640(LH-CX640X)LH-CX245(LH-CX245X)LH-CX247(LH-CX247X)LH-CX246(LH-CX246X)MOD

2、ELS : LH-CX245(LH-CX245X)/LH-CX246(LH-CX246X)/LH-CX247(LH-CX247X)/LH-CX640(LH-CX640X)SERVICE MANUALP/NO : 3829RGP015NDECEMBER, 2004PROG./PRESETPROG.RadioFans.CN 收音机爱 好者资料库CONTENTSSECTION 1 . . . . SUMMARYSECTION 2 . . . . CABINET & MAIN CHASSISSECTION 3 . . . . ELECTRICALSECTION 4 . . . . MECHANISM

3、OF VCR PARTSECTION 5 . . . . MECHANISM OF DVD PARTSECTION 6 . . . . REPLACEMENT PARTS LISTRadioFans.CN 收音机爱 好者资料库1-2SECTION 1SUMMARYCONTENTSPRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRODUCTS. 1-3SERVICING PRECAUTIONS. 1-4 General Servicing Precautions Insulation Checking Prodedure Electrostatica

4、lly Sensitive DevicesSERVICE INFORMATION FOR EEPROM IC SETTING(VCR).1-5SERVICE INFORMATION FOR EEPROM (DVD).1-6SPECIFICATIONS. 1-71-3IMPORTANT SAFETY NOTICEThis manual was prepared for use only by properly trained audio-video servicetechnicians.When servicing this product, under no circumstances sho

5、uld the originaldesign be modified or altered without permission from LG ElectronicsCorporation. All components should be replaced only with types identical tothose in the original circuit and their physical location, wiring and lead dressmust conform to original layout upon completion of repairs.Sp

6、ecial components are also used to prevent x-radiation, shock and fire haz-ard. These components are indicated by the letter “x” included in their compo-nent designators and are required to maintain safe performance. No deviationsare allowed without prior approval by LG Electronics Corporation.Circui

7、t diagrams may occasionally differ from the actual circuit used. This way,implementation of the latest safety and performance improvement changesinto the set is not delayed until the new service literature is printed.CAUTION: Do not attempt to modify this product in any way. Never performcustomized

8、installations without manufacturers approval. Unauthorized modi-fications will not only void the warranty, but may lead to property damage oruser injury.Service work should be performed only after you are thoroughly familiar withthese safety checks and servicing guidelines.GRAPHIC SYMBOLSThe exclama

9、tion point within an equilateral triangle is intended toalert the service personnel to important safety information in theservice literature.The lightning flash with arrowhead symbol within an equilateral tri-angle is intended to alert the service personnel to the presence ofnoninsulated “dangerous

10、voltage” that may be of sufficient magni-tude to constitute a risk of electric shock.The pictorial representation of a fuse and its rating within an equi-lateral triangle is intended to convey to the service personnel thefollowing fuse replacement caution notice: CAUTION: FOR CONTINUED PROTECTION AG

11、AINST RISKOF FIRE, REPLACE ALL FUSES WITH THE SAME TYPE ANDRATING AS MARKED NEAR EACH FUSE.SERVICE INFORMATIONWhile servicing, use an isolation transformer for protection from AC line shock.After the original service problem has been corrected, make a check of the fol-lowing:FIRE AND SHOCK HAZARD1.

12、Be sure that all components are positioned to avoid a possibility of adjacentcomponent shorts. This is especially important on items trans-ported to andfrom the repair shop.2. Verify that all protective devices such as insulators, barriers, covers, shields,strain reliefs, power supply cords, and oth

13、er hardware have been reinstalledper the original design. Be sure that the safety purpose of the polarized lineplug has not been defeated.3. Soldering must be inspected to discover possible cold solder joints, soldersplashes, or sharp solder points. Be certain to remove all loose foreign par-ticles.

14、4. Check for physical evidence of damage or deterioration to parts and compo-nents, for frayed leads or damaged insulation (including the AC cord), andreplace if necessary.5. No lead or component should touch a high current device or a resistor ratedat 1 watt or more. Lead tension around protruding

15、metal surfaces must beavoided.6. After reassembly of the set, always perform an AC leakage test on allexposed metallic parts of the cabinet (the channel selector knobs, antennaterminals, handle and screws) to be sure that set is safe to operate withoutdanger of electrical shock. DO NOT USE A LINE IS

16、OLATION TRANS-FORMER DURING THIS TEST. Use an AC voltmeter having 5000 ohms pervolt or more sensitivity in the following manner: Connect a 1500 ohm, 10watt resistor, paralleled by a .15 mfd 150V AC type capacitor between aknown good earth ground water pipe, conduit, etc.) and the exposed metal-lic p

17、arts, one at a time. Measure the AC voltage across the combination of1500 ohm resistor and .15 mfd capacitor. Reverse the AC plug by using anon-polarized adaptor and repeat AC voltage measurements for eachexposed metallic part. Voltage measured must not exceed 0.75 volts RMS.This corresponds to 0.5

18、milliamp AC. Any value exceeding this limit consti-tutes a potential shock hazard and must be corrected immediately.TIPS ON PROPER INSTALLATION1. Never install any receiver in a closed-in recess, cubbyhole, or closely fittingshelf space over, or close to, a heat duct, or in the path of heated air fl

19、ow.2. Avoid conditions of high humidity such as: outdoor patio installations wheredew is a factor, near steam radiators where steam leakage is a factor, etc.3. Avoid placement where draperies may obstruct venting. The customershould also avoid the use of decorative scarves or other coverings thatmig

20、ht obstruct ventilation.4. Wall- and shelf-mounted installations using a commercial mounting kit mustfollow the factory-approved mounting instructions. A product mounted to ashelf or platform must retain its original feet (or the equivalent thickness inspacers) to provide adequate air flow across th

21、e bottom. Bolts or screwsused for fasteners must not touch any parts or wiring. Perform leakage testson customized installations.5. Caution customers against mounting a product on a sloping shelf or in a tilt-ed position, unless the receiver is properly secured.6. A product on a roll-about cart shou

22、ld be stable in its mounting to the cart.Caution the customer on the hazards of trying to roll a cart with small cast-ers across thresholds or deep pile carpets.7. Caution customers against using extension cords. Explain that a forest ofextensions, sprouting from a single outlet, can lead to disastr

23、ous conse-quences to home and family.A.C. Voltmeter1500 OHM10 WATTPlace this probeon each exposedmetal part.Good Earth Groundsuch as the WaterPipe, Conduit, etc.0.15uFPRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRODUCTS1-4SERVICING PRECAUTIONSCAUTION: Before servicing the HOME THEATER COMBIcovered

24、 by this service data and its supplements andaddends, 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.Remember Safety Fir

25、st:General Servicing Precautions1. Always unplug the HOME THEATER COMBI AC powercord from the AC power source before:(1)Removing or reinstalling any component, circuit board, module, or any other assembly.(2)Disconnecting or reconnecting any internal electricalplug or other electrical connection.(3)

26、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 HOME THEATERCOMBI or any of its assemblies.3. Unless sp

27、ecified 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 no

28、t defeat any plug/socket B+ voltage interlocks withwhitch instruments covered by this service manual mightbe equipped.5. Do not apply AC power to this HOME THEATER COMBIand/or any of its electrical assemblies unless all solid-statedevice heat sinks are correctly installed.6. Always connect the test

29、instrument ground lead to anappropriate ground before connecting 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 t

30、he 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 include Metal panels,Input terminals, Earphone jacks,etc.Electrostatically Sensitive (ES) De

31、vicesSome 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 followin

32、g 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, obta

33、in 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 conductive surface such as aluminum foil

34、, to prevent electrostatic charge buildup or exposure of the assembly.3. Use only a grounded-tip soldering iron to solder or unsolderES devices.4. Use only an anti-static solder removal device. Somesolder removal devices not classified as “anti-static” cangenerate electrical charges sufficient to da

35、mage ES devices.5. Do not use freon-propelled chemicals. These can generate an electrical charge sufficient to damage ESdevices.6. Do not remove a replacement ES device from its protec-tive package until immediately before you are ready toinstall it. (Most replacement ES devices are packaged withlea

36、ds electrically shorted together by conductive foam,aluminum foil,or comparable conductive material).7. Immediately before removing the protective material fromthe leads of a replacement ES device, touch the protectivematerial to the chassis or circuit assembly into which thedevice will be installed

37、.Caution: Be sure no power is applied to the chassis orcircuit, 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 clothes fabric or the liftingof your foot from a carpet

38、ed floor can generate static elec-tricity sufficient to damage an ES device.)1-5SERVICE INFORMATION FOR EEPROM IC SETTING(VCR)MODELNAMEHEXBINARYLH-CX246OPT13800000000OPT2ED00000000OPT32000000000OPT48A00000000OPT54100000000OPT6AF00000000LH-CX245OPT13800000000OPT2ED00000000OPT32000000000OPT48A00000000

39、OPT54100000000OPT6AF00000000LH-CX247OPT13800000000OPT2ED00000000OPT32000000000OPT48A00000000OPT54100000000OPT6AF00000000LH-CX640OPT13800000000OPT2ED00000000OPT3A000000000OPT48A00000000OPT56100000000OPT6AF00000000WR : OK I : EXIT MOVE : F GEDIT : DE1. DETECT NEW EEPROM (OPTION EDITSCREEN)- Eeprom EDI

40、T screen automatically appears ifreplacing Eeprom.- Setup option data using the cursor Up/Down keyof a remote control.(Setup upon BOM depending on OPT1OPT6model) Since an initial remote control is set to LG for LGmodel, appropriately set optiona data using thecursor Up/Down key.2. EEPROM WRITED COMP

41、LETE SCREEN- Writes data on EEPROM by using REMOCONOK. - If completing the option data screen with a menukey, Powering Off is automatically done and theoption edit screen is arranged.3. PG ADJUST- Plays PAL SP TAPE for adjusting the AUTO PG. - A 0:00:00 is played in the field if pressing thefront pl

42、ay with Remocon number 1 key playedduring PAL SP.- The 0:00:00 in the field represents position of theTRACKING PRESET.- OFF is displayed in the field if pressing the frontplay key with the remocon number 1 in the sta-tus of the tracking preset pressed, and ON isdisplayed in the field if AUTO PG oper

43、ation isautomatically performed and completed.- DECK STOP plays if above operation is com-pleted. Set operation is performed depending onchanged PG values. These values are stored inthe EEPROM area. 4. EEPROM INITIAL- SETUP is displayed in the field if pressing theFRONT REC KEY with the remocon numb

44、erCLEAR key pressed in the status of poweringOff.- AUTO SEARCH is done since the initial screenof ACMS is serviced if powering On.- Check basic operation (PLAY/RECORD.)EEPROM option code No. settingEEPROM option code No. setting procedureNAMEHEXBINARYOPT10000000000OPT20000000000OPT30000000000OPT4000

45、0000000OPT50000000000OPT60000000000WR : OK I : EXIT MOVE : F GEDIT : DEMASKROM : R00EEPROM : R00 LG CODE1-6SERVICE INFORMATION FOR EEPROM (DVD)* OPTION NTSC model doesnt have VCR option and use DVD option BF as VCR option. (only DVD exist) PAL model has another separate VCR option. (Both VCR and DVD

46、 exist)MODELNAMELH-CX245LH-CX246LH-CX247LH-CX64000F78705FC220000000A00000000000000F78705FC220000000A00000000000000F78705FC220000000A00000000000000F78705FCA200000000000000000000OPTOPTOPTOPTOPTOPTOPTOPTOPTOPTOPTOPTOPTOPTOPTOPT123456789ABCDEFGDETECT NEW EEPROM (OPTION EDIT SCREEN)POWER ONDVD LOGO Statu

47、s (NO Disk status)Remotecontrol Pause key-1-4-7-2 in order.Press number 09, Press charaterAF (16 for a while)Use arrow key (F D G E) to moveto approprite position and makechangesPress pause key onceChange will be applied when powerOFF-ON.1-7SPECIFICATIONSGeneralPower requirementsRefer to main labelP

48、ower consumptionRefer to main labelDimensions (approx.)430 X 81 X 360 mm (w/h/d)Mass (approx.)5.8 kgOperating temperature5C to 40C (41F to 95F)Operating humidity5 % to 90 %Timer24 hours display tapeDVD SectionLaser Semiconductor laser, wavelength 650 nmSignal systemPAL/NTSCFrequency responseDVD (PCM

49、 96 kHz): 8 Hz to 44 kHz DVD (PCM 48 kHz): 8 Hz to 20 kHzCD: 8 Hz to 20 kHzSignal-to-noise ratioMore than 70 dB (analog out connectors only)Harmonic distortionLess than 1.0%Dynamic rangeMore than 60 dB (DVD, CD)OutputsS-VIDEO OUT(Y) 1.0 V (p-p), 75 ohms, negative sync, Mini DIN 4-pin x 1(C) 0.3 V (p

50、-p) 75 ohmsVCR SectionTape speed PAL/MESECAM; 23.39 mm/s (SP), 16.69 mm/s (LP)NTSC (Playback only); 35.35 mm/s (SP), 16.67 mm/s (LP), 11.12 mm/s (EP)Maximum recording timeSP: 4 h (E-240 tape), LP: 8 h (E-240 tape)Rewind timeAbout 180 min (E-180 tape)Input levelVIDEO:1.0 V(p-p), 75 ohms, unbalancedAU