LG-LGXBR342-cdrec-sm 维修电路原理图.pdf

VCR+DVD RECODERSERVICE MANUALMODEL : LGXBR342CAUTIONBEFORE SERVICING THE UNIT, READ THE “SAFETYPRECAUTIONS”IN THIS MANUAL.MODEL : LGXBR342SERVICE MANUALP/NO : 3829RGN002WPrinted in KoreaJANUARY, 2004CD-R/RWRadioFans.CN 收音机爱 好者资料库1-1SECTION 1SUMMARYCONTENTSPRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRODUCTS. 1-2SERVICING PRECAUTIONS. 1-3SPECIFICATIONS. 1-4RadioFans.CN 收音机爱 好者资料库1-2IMPORTANT SAFETY NOTICEThis manual was prepared for use only by properly trained audio-video servicetechnicians.When servicing this product, under no circumstances should the originaldesign be modified or altered without permission from Zenith 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.Special 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 Zenith Electronics Corporation.Circuit 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 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 exclamation 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 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 AGAINST 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. 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 other 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.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 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 ISOLATION 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 parts, 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 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 flow.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 thatmight 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 the 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 should 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 disastrous 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 PRODUCTS1-3SERVICING PRECAUTIONSCAUTION: Before servicing the VCR + DVD RECODER cov-ered by this service data and its supplements and addends,read and follow the SAFETY PRECAUTIONS. NOTE: ifunforeseen circumstances create conflict between the fol-lowing servicing precautions and any of the safety precau-tions in this publications, always follow the safety precau-tions.Remember Safety First:General Servicing Precautions1. Always unplug the VCR + DVD RECODER AC power cordfrom 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)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 VCR + DVDRECODER 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 VCR + DVD RECODERand / or any of its electrical assemblies unless all solid-state device heat sinks are correctly installed.6. Always connect the test 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 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 include Metal panels,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 electrical assembly equipped with ES devices, place the assembly on a conductive surface such as aluminum foil, 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 damage 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 withleads 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.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 carpeted floor can generate static elec-tricity sufficient to damage an ES device.)1-4SPECIFICATIONSGeneralPower requirementsAC 120V, 50/60 HzPower consumption35WDimensions (approx.)430 X 83.5 X 360 mmMass (approx.)6.8 kgOperating temperature 5 C 40 CStandard Condition -20 C -60 CSignal system NTSCVDR PARTRead Disc FormatDVD Disc : DVD Video Specification Book.CD-DA Disc : RED Book.Write Disc Format DVD-R/DVD-R/W Disc : DVD-RW Recorder Specification BookVideo SystemNTSCData MultiplexingMPEG-2(ISO/IEC 13818-1)Data Decoding StandardsMPEG-1, MPEG-2Audio CompressionRead : AC-3 : ATSC Standard for ATV MPEG-1, MPEG-2Write : MPEG-1, Layer-2VCR PARTVideo Head SystemDouble azimuth 4head helical scanningTape FormatTape width 12.7mm(0.5 inch)Timer24hours display typeOUTOUTVIDEO OUTPUTS 1.0 V (p-p), 75 negative sync,RCA jack x 1S-VIDEO OUTPUT(Y)1.0 V (p-p), 75 negative sync, Mini DIN 4-pin x 1(C)0.3 V (p-p), 75 COMPONENT VIDEO OUTPUT(Y)1.0 V (p-p),75 negative sync, RCA jack x 1(Pb)/(Pr)0.7 V (p-p), 75 Audio output (analog output)(-)6dBm, less than 1k RCA jack x 2Audio output (digital output)0.5 V (p-p), 75 , RCA jack x 1Audio output (optical output)5 V (p-p), 75 , Optical connector x 12-1SECTION 2CABINET & MAIN CHASSISCONTENTSEXPLODED VIEWS.2-21. Cabinet and Main Frame Section.2-22. Packing Accessory Section.2-32-2EXPLODED VIEWS1. Cabinet and Main Frame Section284261452452320265467468263264250300463463463261A261A261A283280?A43457276260457463457469469A50A47A48A46A00457TU701323A52270A26A60466463466256463255469257A47AA44452A54321BCD2-32. Packing Accessory SectionBATTERY808BAG804PACKING803806INSTRUCTION ASSEMBLY CABLE(COAXIAL)810 CABLE ASSY RF801REMOCON900BOX CARTON802PACKING803811812PLUG ASSY 1WAYPLUG ASSY 2WAYOPTIONAL PARTS3-13-1SECTION 3ELECTRICALCONTENTSOVERALL WIRING DIAGRAM.3-2VCR PARTELECTRICAL ADJUSTMENTPROCEDURES.3-3VCR ELECTRICAL TROUBLESHOOTINGGUIDE.3-41. POWER(SMPS) CIRCUIT.3-42. SYSTEM/KEY CIRCUIT .3-73. SERVO CIRCUIT .3-84. OSD CIRCUIT .3-105. Y/C CIRCUIT.3-116. TUNER/IF CIRCUIT.3-157. Hi-Fi CIRCUIT.3-17BLOCK DIAGRAMS.3-201. POWER(SMPS) BLOCK DIAGRAM.3-20 2. TUNER/MTZ BLOCK DIAGRAM.3-22 3. Y/C BLOCK DIAGRAM.3-24 4. NORMAL AUDIO BLOCK DIAGRAM.3-26 5. JACK BLOCK DIAGRAM .3-28 6. Hi-Fi BLOCK DIAGRAM.3-30 7. SYSTEM BLOCK DIAGRAM.3-32CIRCUIT DIAGRAMS.3-341. POWER(SMPS) CIRCUIT DIAGRAM.3-34 2. TU/IF CIRCUIT DIAGRAM .3-36 3. A/V CIRCUIT DIAGRAM.3-38 4. JACK CIRCUIT DIAGRAM.3-40 5. Hi-Fi CIRCUIT DIAGRAM.3-42 6. SYSTEM CIRCUIT DIAGRAM.3-447. TIMER CIRCUIT DIAGRAM .3-46 WAVEFORMS .3-48 CIRCUIT VOLTAGE CHART.3-50PRINTED CIRCUIT DIAGRAMS.3-521. VCR P.C.BOARD.3-52 2. POWER P.C.BOARD .3-54 3. TIMER P.C.BOARD .3-54 4. KEY P.C.BOARD .3-56 5. JACK P.C.BOARD .3-57VDR PARTELECTRICAL TROUBLESHOOTINGGUIDE & WAVEFORMS.3-581. POWER(SMPS) CIRCUIT.3-58BLOCK DIAGRAMS.3-651. VDR MAIN H/ W BLOCK DIAGRAM.3-652. POWER BLOCK DIAGRAM.3-663. AUDIO IN/ OUT BLOCK DIAGRAM.3-674. CPU & CONTROL REGISTER BLOCK DIAGRAM.3-685. VIDEO IN/ OUT BLOCK DIAGRAM.3-69CIRCUIT DIAGRAMS.3-701. E5_BGA, POWER, UART2 CIRCUIT DIAGRAM.3-702. DDR_SDRAM, FLASH CIRCUIT DIAGRAM.3-72 3. RST. CONTROL/STATUS_REG/ATAPI,HOST_CPLD/LATCH CIRCUIT DIAGRAM .3-74 4. 1394, ETHERNET_CONNECTOR CIRCUIT DIAGRAM .3-76 5. VIDEO_IN/OUT CIRCUIT DIAGRAM.3-78 6. AUDIO IN/OUT, NON-STD_VIDEO CIRCUIT DIAGRAM .3-80 7. AUDIO DAC, VIDEO_Y/MIXER CIRCUIT DIAGRAM .3-82 8. FRONT A/V, 1934 JACK CIRCUIT DIAGRAM .3-84 WAVEFORMS .3-86 CIRCUIT VOLTAGE CHART.3-90PRINTED CIRCUIT DIAGRAMS.3-941. VCR P.C.BOARD(TOP VIEW).3-94 2. POWER P.C.BOARD (BOTTOM VIEW).3-96RL-01A LOADER PARTELECTRICAL TROUBLESHOOTING GUIDE.3-98BLOCK DIAGRAMS & DESCRIPTION.3-1121. OVERALL BLOCK DIAGRAM .3-1122. MAJOR IC INTERNAL BLOCK DIAGRAM AND PIN DESCRIPTION .3-1133. MAJOR IC INTERNAL BLOCK DIAGRAM AND PIN DESCRIPTION .3-1184. IC302(UPD76F0047):MICOM.3-127WAVEFORMS.3-1311. POWER & RESET SIGNAL .3-1312. MAIN CLOCK1 FOR IC202 (16.9MHZ).3-1313. MAIN CLOCK2 FOR IC302 (20MHZ).3-1324. SDRAM CLOCK .3-1325. TRAY OPEN/CLOSE SIGNAL 1.3-1336. TRAY OPEN/CLOSE SIGNAL 2.3-1337. SLED MOVE SIGNAL 1.3-1348. SLED MOVE SIGNAL 2.3-1349. FOCUS SEARCH SIGNAL.3-13510. LASER TURN ON SIGNAL .3-13511. DISC TYPE JUDGEMENT WAVEFORM (CD SERIES) .3-13612. DISC TYPE JUDGEMENT WAVEFORM (CD&CD-R).3-13613. DISC TYPE JUDGEMENT WAVEFORM (CD-RW).3-13714. DISC TYPE JUDGEMENT WAVEFORM (DVD SERIES).3-13715. DISC TYPE JUDGEMENT WAVEFORM (DVD_SINGLE&R).3-13816. DISC TYPE JUDGEMENT WAVEFORM (DVD _DUAL).3-13817. DISC TYPE JUDGEMENT WAVEFORM (DVDRW).3-13918. SPINDLE WAVEFORM1.3-13919. SPINDLE WAVEFORM2.3-14020. FOCUS ON SIGNAL(CD)