LG-LPCLM445-pr-sm 维修电路原理图.pdf

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1、MP3/CD LOGIC DECKCASSETTE RECORDERSERVICE MANUALMODEL: LPC-LM440A/XLPC-LM445A/XSERVICE MANUAL MODEL: LPC-LM440A/X LPC-LM445A/XRadioFans.CN 收音机爱 好者资料库- 1-1 -CONTENTS SECTION 1.GENERAL SERVICING PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

2、-2 ESD PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4 SPECIFICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5 IDENTIFICATIONS OFCONTROLS . . . . . .

3、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6 SECTION 2.ELECTRICAL SECTION ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 TROUBLESHOOTING GUIDE . . . . . . . . . . . . . . . . . . . .

4、 . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2 INTERAL BLOCK DIAGRAM OF ICs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17 IC/TR VOLTAGE & PIN DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23 BLOCK DIAGRAM

5、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-27 SCHEMATIC DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-29 WIRING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . .

6、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-41 PRINTED CIRCUIT BOARD DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-43 SECTION 3. EXPLODED VIEWS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1 SECTION 4. REPLACEMENT

7、 PARTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1RadioFans.CN 收音机爱 好者资料库- 1-2 -SECTION 1. GENERAL SERVICING PRECAUTIONSNOTES 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

8、 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

9、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

10、 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

11、 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, a cottonswab should be used, taking care not to distort this.6) Never attempt to disassemble the pick-up.Spring by excess pressure. If the lens

12、 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.Storage in conductive bagDrop impactNEVER look d

13、irectly at the laser beam, and dont let contact fingers or other exposed skin.MagnetHow to hold the pick-upConductive SheetCotton swabPressurePressure- 1-3 -NOTES REGARDING COMPACT DISC PLAYER REPAIRS1. Preparations1) Compact disc players incorporate a great many ICs as well as the pick-up (laser di

14、ode).These componentsare sensitive to, and easily affected by, static electricity. If such static electricity is high voltage, componentscan 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

15、s. Care must betaken, therefore, to avoid repair or storage where the temperature of humidity is high, where strong magnet-ism 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 equipme

16、nt, 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 p

17、revent 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 sta-tic electricity changes in the clothing to escape from the arm

18、band.7) The laser beam from the pick-up should NEVER be directly facing the eyes or bare skin.Resistor(1 Mohm)ConductiveSheetResistor(1 Mohm)Armband- 1-4 - ESD PRECAUTIONSElectrostatically Sensitive Devices (ESD)Some semiconductor (solid state) devices can be damaged easily by static electricity. Su

19、ch componentscommonly are called Electrostatically Sensitive Devices (ESD). Examples of typical ESD devices are integratedcircuits and some field-effect transistors and semiconductor chip components.The following techniques shouldbe used to help reduce the incidence of component damage caused by sta

20、tic electricity.1. Immediately before handling any semiconductor component or semiconductor-equipped assembly, drain offany electrostatic charge on your body by touching a known earth ground. Alternatively, obtain and wear acommercially available discharging wrist strap device, which should be remov

21、ed for potential shock reasonsprior to applying power to the unit under test.2. After removing an electrical assembly equipped with ESD devices, place the assembly on a conductive sur-face such as aluminum foil, to prevent electrostatic charge buildup or exposure of the assembly.3. Use only a ground

22、ed-tip soldering iron to solder or unsolder ESD devices.4. Use only an anti-static solder removal device. Some solder removal devices not classified as anti-static cangenerate electrical charges sufficient to damage ESD devices.5. Do not use freon-propelled chemicals.These can generate electrical ch

23、arges sufficient to damage ESDdevices.6. Do not remove a replacement ESD device from its protective package until immediately before you areready to install it. (Most replacement ESD devices are packaged with leads electrically shorted together byconductive foam, aluminum foil or comparable conducti

24、ve materials).7. Immediately before removing the protective material from the leads of a replacement ESD device, touch theprotective material to the chassis or circuit assembly into which the device will by installed.CAUTION : BE SURE NO POWER IS APPLIED TO THE CHASSIS OR CIRCUIT, AND OBSERVE ALLOTH

25、ER SAFETY PRECAUTIONS.8. Minimize bodily motions when handing unpackaged replacement ESD devices. (Otherwise harmless motionsuch as the brushing together of your clothes fabric or the lifting of your foot from a carpeted floor can gen-erate static electricity sufficient to damage an ESD device).CAUT

26、ION. GRAPHIC SYMBOLSTHE LIGHTNING FLASH WITH APROWHEAD SYMBOL. WITHIN AN EQUILATERAL TRIANGLE, ISINTENDED TO ALERT THE SERVICE PERSONNEL TO THE PRESENCE OF UNINSULATED “DAN-GEROUS VOLTAGE” THAT MAY BE OF SUFFICIENT MAGNITUDE TO CONSTITUTE A RISK OFELECTRIC SHOCK.THE EXCLAMATION POINT WITHIN AN EQUIL

27、ATERAL TRIANGLE IS INTENDED TO ALERT THESERVICE PERSONNEL TO THE PRESENCE OF IMPORTANT SAFETY INFORMATION IN SERVICELITERATURE.- 1-5 - SPECIFICATIONSGeneralCDTAPEPower supplyRefer to the back panel of the unit.Power consumption40WMassExternal dimensions (W x H x D)456 x 178 x 338 mmOutput Power 5W X

28、 2 , 10WSpeakers3.2 X 3Battery OperationDC 12V, 8 “D”(R20) batteries (not supplied)Frequency response 100 - 18000 HzSignal-to-noise ratio 65 dB T.H.D%Tuning Range87.5 -108 MHz, 65 -74 MHz or 87.5 -108 MHzIntermediate Frequency10.7 MHzAntennaTelescopic antennaTuning Range 522 - 1620 kHz or 520 - 1720

29、kHzIntermediate Frequency450 kHzAntennaFerrite bar antennaRecording System4 Tracks 2 channel stereoFrequency Response125 - 8000HzSignal to Noise Ratio40/45dB (REC/PLAY)Designs and specifications are subject to change without notice.MODELSECTIONTunerAMFM(MW)LPC-LM440ALPC-LM445A5.1kg0.5- 1-6 - IDENTIF

30、ICATIONS OF CONTROLS Front Front - 1-7 -Rear PanelRemote ControlBottom Panel- 1-8 - 2-1 -SECTION 2. ELECTRICAL ADJUSTMENTS1.TAPE DECK ADJUSTMENTDECK MODETEST TAPETEST POINTADJUSTMENTADJUST FORPLAY BACKMTT-114L/R OutputL/R Maximum2.RECORD BIAS ADJUSTMENTDECK MODETEST TAPETEST POINTADJUSTMENTADJUST FO

31、RAUTO-RVS75KHz5KHzAUTO-STOP65KHz5KHz3.TAPE SPEED ADJUSTMENTDECK MODETEST TAPETEST POINT ADJUSTMENTADJUST FORPLAYBACKMTT-111L/R Output3kHz50HzAzimuth adjusting screwSR490REC MODEMTT-5511C465 OR C415(DECKCIRCUIT B- POINT)L405- 2-2 - TROUBLESHOOTING GUIDE CD PARTTURN ON CDOPEN CLOSE CHECKCONNECTOR CHEC

32、K (PN813)“READING”DISPLAY CHECKCONNECTOR CHECK(PN802,PN806)CHECK MICOM INTERFACECIRCUIT (PN805)READING OK CHECKCONNECTOR CHECK (PN801)CHECK PICKUP MOVEMENTCHECK AM5810FP (IC802)CHECK LC78690N (IC801)CONNECTOR CHECK (PN806 Pin1 & Pin3)IF PLAY, AUDIOOUTPUT CHECKOKYESYESYESYESNONONONONONONO- 2-3 -OPEN

33、COLOSE NG“READING ”DISLPAY CHECK (=ONLY “CD ”DISPLAY)DOOR OPEN/CLOSEDISLPLAY CHECKOPEN/CLOSE S/W CHECKDEFECTIVE CONNECTOR ORMAIN POWER SUPPLYDEFECTIVE IC804DEFECTIVE MICOM ORDSP &14P FFC CABLEIC801 PIN=18 CHECK“2.45V”PICK-UP UNIT OR Q801DEFECTIVEMAIN BD CHECKQ102 “C ” 4.6V)Check Q101 “B ”4.5VCONNECT

34、OR LOCKINGCHECK (PN813)AD 5V CHECK(PN805 Pin3)CONNECTOR LOCKING CHECK(PN801,PN805,PN802,PN806)CHECK POWER SUPPLY(MAIN PN251)PN251 PIN 5=6.2V ,PIN 7=6.2VCHECK VOLTAGE CD BD IC804Pin3=6.2V,Pin 2&4=3.3VCHECK INTERFACE WITH MICOM MAIN CN111 Pin6,7,8,9 ,10,11,12 ,13LASER ONCD BD PN801 Pin 10=1.96VNONONON

35、ONONONOYESYESYESYESYESYES- 2-4 -READING OK CHECK (=“NO DISC ”DISPLAY)CONNECTOR LOCKINGCHECK(PN801)CHECK PN802 Pin3,4(SL+,SL-)CHECK PN801 Pin13,16(FA-,FA+)CHECK PN802 Pin5,6(SP+,SP-)CHECK PN801 Pin14,15(TA+,TA-)CHECK PN801 Pin10(LD)DEFECTIVE PICKUP ORIC802 OR IC801DEFECTIVE PICKUP ORIC802 OR IC801DEF

36、ECTIVE PICK-UP ORIC802 OR IC801DEFECTIVE PICKUP ORIC802 OR IC801DEFECTIVE PICKUP ORIC801 OR Q801DOES SLED MOVE?DOSE LENSE MOVE?(UP&DOWN)DOSE LASER LIGHT?DOES SPINDLE ROTATE?IS READING OK?YESYESYESNONONONONONONONONONOYESYESABCDE- 2-5 -READING OK CHECK #A(=“NO DISC ”DISPLAY)DOSE SLIN WAVEFORMAPPEAR AT

37、 (IC802 Pin5)DRIVE WAVEDEFECTIVE IC801DEFECTIVE IC802DEFECTIVE PICK-UPSLED MOTORDEFECTIVE PN802CONNECTORDOSE SL+WAVEFORMAPPEAR AT(IC802 Pin13 )SLED MOTOR WAVECHECK PN802 CONNECTOR LINEYESNONONONONOA- 2-6 -READING OK CHECK #B(=“NO DISC ”DISPLAY)DOSE FAIN WAVEFORMAPPEAR AT (IC802 Pin22)DRIVE WAVEDEFEC

38、TIVE IC801DEFECTIVE IC802DEFECTIVE PICK-UPFOCUS ACTUATORDEFECTIVE PN801CONNECTORDOSE FA+WAVEFORMAPPEAR AT(IC802 Pin16 )FOCUS COIL DRIVE WAVECHECK PN801 CONNECTOR LINEYESNONONONONOB- 2-7 -READING OK CHECK #C(=“NO DISC ”DISPLAY)Q801 EMITTER VOLTAGECHECK .3.1V O.KLASER CONTROLVOLTAGE CHECKIC801 Pin 18.

39、2.45DEFECTIVE IC801DEFECTIVE IC801DEFECTIVE Q801DEFECTIVE PICK-UPFOCUS ACTUATORDEFECTIVE PN801CONNECTORQ801 VOLTAGE CHECK.1.96VCHECK PN801 CONNECTOR LINEYESYESNONONONONONOC- 2-8 -READING OK CHECK #D(=“NO DISC ”DISPLAY)DOSE SPIN WAVEFORMAPPEAR AT (IC802 Pin6)SPINDLE DRIVE WAVEDEFECTIVE IC801DEFECTIVE

40、 IC802DEFECTIVE PICK-UPSPINDLE MOTOORDEFECTIVE PN802CONNECTORDOSE SP+WAVEFORMAPPEAR AT(IC802 Pin11)SPINDLE MOTOR DRIVE WAVECHECK PN802 CONNECTOR LINEYESNONONONONOD- 2-9 -READING OK CHECK #E(=“NO DISC ”DISPLAY)DOSE TAIN WAVEFORMAPPEAR AT (IC801 Pin23)TRACKING DRIVE WAVEDEFECTIVE IC801DEFECTIVE IC802D

41、EFECTIVE PICKUP OR IC801DEFECTIVE PN801CONNECTORDOSE TA+WAVEFORMAPPEAR AT(IC802 Pin17 )TRACKING COIL DRIVE WAVECHECK PN801 CONNECTOR LINEDOSE RF SIGNAL APPEAR?(IC801 PORT2)WAVEFORM#6YESNONONONONOE- 2-10 - MAIN POWERMain Power input (AC-cord in)LCD Display ”Hello”Check the Voltage-selector110V/230V (

42、Duble Voltage only)Check the DC outof C202(+)Check the FuseReplace the FuseReplace D201,D202,D203D204Check theD901,D902,D903,D904(POWER BD)Q251 Emittor VoltageCheck(.9.6V)REPLACE Q251REPLACE IC271POWER SENSEBLOCK CHECKRESETBLOCK CHECKREPLACE D181,D182,D183REPLACE X102REPLACE MICOM IC(IC101 LC877480)

43、IC271 Vout Voltage Check(.5.2V)Q265 Collector VoltageCheck(.5V)Q173 Collector VoltageCheck(.4.6V)D181,D182,D183 CathodeVoltage Check(4.6V)OSC CHECK(X102:9.8304MHz)NONOYESNONONONONONONONO- 2-11 - MUTING CIRCUIT(MUTE) FUNCTION MODE AUDIO ABNORMALDose “HIGH ”appear atQ601,Q651,Q256(SUB-W)“B ”Check the

44、“HIGH ”of theIC101 Pin 9,47Check the IC101Check the patternReplace the Q601,Q651,Q256Check the signal input of PN251 “R-CH ”“L-CH ”Check the CD BDCheck the “LOW ”of Q601,Q605,Q256 “E ”MUTETAPE FUNCTIONCheck the signal input of IC301 Pin 3,26Refer to “TAPE Trouble Shooting ”CD FUNCTIONMUTECheck the s

45、ignal input ofIC301 Pin 6,23TUNER FUNCTIONCheck the signal input of IC301Pin 4,25Refer to “Tuner Pack TroubleShooting ”NONONONONOYESYESYESYESYESYESYESYES- 2-12 - IC301 TROUBLESHOOTINGCheck the Power supplying toIC301 pin 1Check the DC Output ofQ301(.6.8V)Check the PatternReplace the IC301Check the I

46、C101Check the Data ofIC101 pin 6,7CD TAPE Function)Check the CLK Data ofIC301 pin 14,15Check the IC101 FunctionSelectorENDNONONONOYESYESYESYES- 2-13 - TUNER PACK TROUBLESHOOTINGCheck the Tuner Power ofPN403 Pin 2 “Tu-B+”Check the DC output of“HIGH ”Q231 “C ”Check the “high ”Q232 “B ”Check the DC out

47、putQ233 “E ”,patternCE :Chip EmableDI :Data Input(From u-com)DO :Data Output(to u-com)CLK :Tuner Mode ClockReplace Tuner pack orMicom 35,36,37,38 CheckIs the normal?ENDNONONOYESYESYES- 2-14 - TAPE TROUBLESHOOTING1) PlayCheck the power supplying toIC401 Pin16Check the DC outputQ241 “C ”Check the “hig

48、h ”IC101 Pin92 or Q242 “B ”Check the patternQ405 “C ”Voltage Check(8.5V)PN402 Pin 3 Voltage Check(12.5V) Q407,Q489 CheckPN402 Pin1 Pin2 Check(NormalSpeed:Q483,+10%:Q481,-10%:Q485)Q487 “C ”Voltage Check:When solenoid is drivedCheck the patternCheck(PB MUTE “Low ”RECMUTE “High ”REC BIAS “Low ”)Check t

49、he Deck MechaReplace the IC201Replacethe Deck MechaCheck the signal output ofIC401 Pin 5,26NONOYESNONOYESYES- 2-15 -2) RECCheck signal out ofIC401 Pin 10,21Check signal in from IC301IC301 Pin 7,22)Replace IC301Replace IC401Check the signal of IC401Pin 7,24 OR PatternCheck REC_B+Voltage(9V)Check the

50、Oscillation ofQ472 “E ”Check Q211 “E ”Voltage(9V)Check Q211 “E ”Voltage(9V)Check Q211 “E ”Voltage(9V)Check the signal ofR463,R413 or L402Pin2,Pin3Check Q405 “B ”“Low ”Check Q405 “C ”“Low ”Check REC_BIAS “High ”Check Mechanism Head orReplace MechanismIs the normal?NONONONONONONOYESYESYESYESYESYES- 2-