LG-LM230-cs-sm 维修电路原理图.pdf

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1、- 1- 1 -CONTENTSSECTION 1. GENERAL SERVICING PRECAUTIONS.1- 2 ESD PRECAUTIONS.1- 4 SPECIFICATIONS.1- 5SECTION 2. ELECTRICAL ADJUSTMENTS.2- 1 TROUBLESHOOTING.2- 3 WAVEFORMS OF MAJOR CHECK POINT.2- 7 BLOCK DIAGRAM.2- 17 SCHEMATIC DIAGRAMS.2- 19 WIRING DIAGRAM.2- 27 PRINTED CIRCUIT DIARGAMS.2- 29 INTER

2、NAL BLOCK DIAGRAM OF ICs.2- 38 REPAIRS REGARDING CD MECHANISM.2- 45SECTION 3. EXPLODED VIEWS CABINET AND MAIN FRAME SECTION .3- 1 TAPE DECK MECHANISM: AUTO STOP DECK(OPTIONAL).3- 3 TAPE DECK MECHANISM: AUTO REVERSE DECK.3- 5 CD MECHANISM.3- 7SECTION 4. SPEAKER.4-1SECTION 5. REPLACEMENT PARTS LIST.5-

3、1RadioFans.CN 收音机爱 好者资料库SECTION 1. GENERALSERVICING 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 use.2) The pick- up should never be subjected to external pressure or impact.

4、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

5、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!Ab

6、solutely 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 len

7、s). 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. (Dono

8、t 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- 2 -Storage in conductive bagDrop impactNEVER look directly at the laser beam, and dont letcontact fingers or oth

9、er exposed skin.MagnetHow to hold the pick- upPressurePressureCotton swabConductive SheetRadioFans.CN 收音机爱 好者资料库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

10、 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 avoi

11、d 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 b

12、e 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

13、 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 s

14、hould NEVER be directly facing the eyes or bare skin.CLEARING MALFUNCTIONYou can reset your unit to initial status if malfunction occur(button malfunction, display, etc.).Using a pointed good conductor(such as driver), simply short the RESET jump wire on the inside of thevolume knob for more than 3

15、seconds. If you reset your unit, you must reenter all its settings(stations, clock, timer)NOTE: 1. To operate the RESET jump wire, pull the volume rotary knob and release it.2. If you wish to operate the RESET jump wire, it is necessary to unplug the power cord.- 1- 3 -ArmbandConductiveSheetResistor

16、(1 Mohm)Resistor(1 Mohm)VOLUME KNOBUPDOWNVOLUMERESET jump wireESD PRECAUTIONSElectrostatically Sensitive Devices (ESD)Some semiconductor (solid state) devices can be damaged easily by static electricity. Such componentscommonly are called Electrostatically Sensitive Devices (ESD). Examples of typica

17、l 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 static electricity.1. Immediately before handling any semiconductor component or semiconductor-

18、 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 removed for potential shock reasonsprior to applying power to the unit under test.2. After remov

19、ing an electrical assembly equipped with ESD devices, place the assembly on a conductivesurface 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 unsolder ESD devices.4. Use only an anti- static solder r

20、emoval 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 charges sufficient to damage ESDdevices.6. Do not remove a replacement ESD device from its

21、 protective package until immediately before you are readyto install it. (Most replacement ESD devices are packaged with leads electrically shorted together byconductive foam, aluminum foil or comparable conductive materials).7. Immediately before removing the protective material from the leads of a

22、 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 ALL OTHERSAFETY PRECAUTIONS.8. Minimize bodily motions when handing unpackaged replacement ESD

23、 devices. (Otherwise harmless motionsuch as the brushing together of your clothes fabric or the lifting of your foot from a carpeted floor cangenerate static electricity sufficient to damage an ESD device).CAUTION. GRAPHIC SYMBOLSTHE LIGHTNING FLASH WITH APROWHEAD SYMBOL. WITHIN AN EQUILATERAL TRIAN

24、GLE, ISINTENDED TO ALERT THE SERVICE PERSONNEL TO THE PRESENCE OF UNINSULATED“DANGEROUS VOLTAGE” THAT MAY BE OF SUFFICIENT MAGNITUDE TO CONSTITUTE A RISK OFELECTRIC SHOCK.THE EXCLAMATION POINT WITHIN AN EQUILATERAL TRIANGLE IS INTENDED TO ALERT THESERVICE PERSONNEL TO THE PRESENCE OF IMPORTANT SAFET

25、Y INFORMATION IN SERVICELITERATURE.- 1- 4 - 2- 1 -TAPE DECK ADJUSTMENT1. AZIMUTH ADJUSTMENTFigure 1. Azimuth Adjustment Connection DiagramCH1 CH2Speaker OutPlayback ModeHeadTest TapeMTT- 114L chR chGNDDual- tracesynchroscopeElectronicVoltmeterL outR outUnitSECTION 2. ELECTRICALADJUSTMENTSThis set ha

26、s been aligned at the factory and normally will not require further adjustment. As a result, it is notrecommended that any attempt is made to modificate any circuit. If any parts are replaced or if anyone tamperswith the adjustment, realignment may be necessary.IMPORTANT1. Check Power- source voltag

27、e.2. Set the function switch to band being aligned.3. Turn volume control to minimum unless otherwise noted.4. Connect low side of signal source and output indicator to chassis ground unless otherwise specified.5. Keep the signal input as low as possible to avoid AGC and AC action.Deck ModeTest Tape

28、Test PointAdjustmentAdjust forA Deck PlaybackMTT- 114Speaker OutDECK ScrewMaximumAzimuth ScrewB Deck PlaybackMTT- 114Speaker OutAzimuth ScrewMaximum2. MOTOR SPEED ADJUSTMENTFigure 2. Motor Speed Adjustment Connection DiagramHeadPlayback ModeUnitSpeaker OutGNDL outR outRecord/PlaybackheadTest TapeMTT

29、- 111Frequency CounterDeck ModeTest TapeTest PointAdjustmentAdjust forRemarkNormal SpeedMTT- 111Speaker OutVR2013kHz 1%A DeckHI- SpeedMTT- 111Speaker Outmore than 5.4kHzHI- Speed Dubbing Mode- 2- 2 -3. RECORD BIAS ADJUSTMENTHeadUnitPN202GNDRecord/PlaybackheadTest TapeMTT- 5511Record/Playbackand Paus

30、e ModeFrequency CounterDeck ModeTest TapeTest PointAdjustmentAdjust forRec/PauseMTT- 5511ERASE HEADL20360kHz5kHz (Auto stop)WIRE(PN202)85kHz5kHz(Auto Reverse)Figure 3. Record Bias Adjustment Connection Diagram- 2- 3 -TROUBLESHOOTINGTurn power on.Is power on?Does initial read work?Does it play?Does i

31、t output audio?Check power supply circuit.PN807 PIN5, 6.2VPN807 PIN7, 5VIC803 PIN 2, 3.3VCheck the connectorPN801, PN802, PN809Check the tracking servo circuit.Check the PN807 PIN1, 3OKYESYESYESYESYESYESNONONOCheck the DISK turnsCheck the LaserCheck the focus circuitCheck the TRAKING circuitNONO- 2-

32、 4 -FAILS TO INITIAL READ AB2V5V0V5V0V1V0V1.2V0V0.8VNONONONONONONONONONOYESYESYESYESYESYESYESYESYESYESYESYESDisc motor turnsDoes RF waveform appear?IC801 Pin3Check the Data transmission fromPN809 pin11 to CD DSPCheck the Data transmission fromPN809 pin13 to MICOMCheck the change of SLDOVoltage(IC801

33、 pin23)Check the change of SL +,SL - Voltage(IC802 pin 18, 19)Check the Voltage change of PN 809PIN20(OPEN, CLOSE)Defective connectorPN809Defective connectorPN809, DefectiveMICOMDefective connectorPN809, DefectiveIC801Defective IC801Defective IC802Defective contact PN802Defective PICK- UPDoes laser

34、light?focus coil drive wareform.TRACKING ERROR wareformIs rotation normal?Defective IC801Defective PICK- UPIs there no dropout of RF signal?Does FA+ waveform appear atIC802 pin13?Does TE waveform appear at 801 pin 15?- 2- 5 -A?NONONONONONOLaser does not light.Is “3.5V” applied to pin of IC 801?Is po

35、wer supplied to laser Q801?(Q 801 collector: about 1.8V)Does laser current flow?1.0V across R808Is data transferred fromMICOM IC ?Does voltage appear at IC802 pin 17, 18?Defective MICOM.Defective MICOM.Defective connector.Defective IC 801, 802 Defective slide motor and/orconnector.Defective LMT SW a

36、nd/orconnector.Defective Q 801 and/or laser.Defective laser and/orconnector.Did pickup return toinnermost circular?Does it stop at inner pickcircular after shift?Is defect output from LMSW applied to pin 2 ofPN802?R8081.0VR8081.0VYESYESYESYESOPENCLOSEYESYESYESYESYESYES70- 2- 6 -BNONONONONOYESYESYESY

37、ESLaser lightsDoes lens move up/down?Check the signal ofFOCUS SEARCH(IC801 Pin 21)Chekc the signal of PN802pin 13, 14Does FE signal appear?(IC801 pin 13)Does DRF signal appear? (IC 801 pin67)Defective IC801Defective IC802Open activator and/or connectorDefective IC801Degraded laser diodeDefective PIC

38、K- UP- 2- 7 -(CH1)(CH2)1. HF signal (RF signal ) waveform(IC801 pin 3) during normal play 2. EFM signal (IC801 pin 3)waveformduring Normal Play3. Focus coil drive waveform(IC802 pin13) When focus search failed or there is no disc on the tray Focus coil drive waveform(FDO: IC801 pin21) andDRF(IC801 p

39、in67) when focus search is accomplished4. Tracking coil drive waveform and TE during tracktraverse(1) When time division is 20mS/Div.1V/Div.(2) When time division 1mS/Div, 1V/Div(During forward track traverse)(3) When time division is 0.5nS/div.(During backward Track Traverse)5. Feed motor drive wav

40、eform(IC 802 pin18)During normal playCH1 : FOCUS COIL DRIVESIGNAL 2V/Div.CH2 : DRFCH1 : TRACKING COIL DRIVESIGNAL 2V/Div. (IC802 pin27)CH2 : TRACKING ERROR(TE: IC801 pin15)1V/Div.(CH2 : TRACKING COIL DRIVE (IC802 pin27)SIGNAL 2V/Div.CH2 : TRACKING ERROR (TE: IC801 pin15)1V/Div.(CH1 : TRACKING COIL D

41、RIVE (IC802 pin27)CH2 : TRACKING ERROR (TE: IC801 pin15)(0.5V/Div.500nS/Div.(1S/Div.1V/Div.(1mS/Div.1V/Div.(0.5V/Div.5S/Div.(2S/Div.0.5V/Div.OVOVOV(CH1)(CH2)(CH1)(CH2)(CH2)OVOVOVOVOVOVOVOVOVWAVEFORMS OF MAJOR CHECK POINT- 2- 8 -VKK PARTDoes DC - 33V appear at CN302 Pin .Check the Voltage of IC301pin

42、51Dose - 33V appear at ZD902(- ) Check the Q903 TURN ONCheck the PATTERNReplace the ZD902Replace the Q903Refer to power circuitENDCheck the - 33V(LOWER)of C916Replace the D704,D705YESYESNONOP-SENS PART Does +5V appear at ZD901?Check the pattern of IC301 Pin .Check the waveform of D913(cathod).Check

43、the R768 and replace ZD901.Replace the D703YESYESNONO2628- 2- 9 -POWER CIRCUIT Check the Fuse Check the DC output of C901(+), C902(- )Check the DC Output ofC930(+)Check the Voltage output of IC901, IC902Check the DC 12VOutput of IC903Check the 5V of CN513 pin 7(CD FUNCTION)ENDReplace the Fuse Check

44、the AC Output of CN901 pin1, 5Check the AC Output ofCN701 PIN 9, 10Replace the IC904Replace the D901, D902,D903, D904Replace the D706, D707, D708, D709Check the IC901, IC902Check the 5V of IC301 pin78Check the “Low” of Q904“B”Check the Q904, CD AssyCheck the power Assy orReplace the TransformerCheck

45、 the power Assyor Replace theTransformerCheck the 5V of IC301PIN13& PN302, CN302, PIN13Check the HIGH ofQ905 “B” and ReplaceCheck the “High” ofIC501 pin 14Check the IC501YESYESYESYESYESYESYESYESYESYESYESNONONONONONONONONONONO- 2- 10 -AUDIO ABNORMALCheck the output of IC601 Pin 12, 17Refer to “IC601T

46、roubleshooting”Refer to “MutingTroubleshooting”Check the 10V(Higher) ofIC601 pin 5 & Check the power circuitCheck the input of IC701 pin3Check the Output of IC701, pin14ENDYESYESYESNONONOMuting circuit (MUTE)Dose “Low” appear at Q702 “B”Check the “High” of Q701,Q751 “B”MUTECheck the connector of Q70

47、2 “B” and GNDReplace the TRYESYESNO- 2- 11 -FUNCTION MODE AUDIO ABNORMALTAPECheck the signal input of IC601 pin 6, 23Refer to “IC202 Troubleshooting”AUXChekc the signal input of IC601, pin 5, 24Check the signal input of JK102Check the signal input of IC601 pin 3, 26Check the signal of CN513 pin 1, 3

48、 orRefer to “CD Troubleshooting”Check the signal input of IC601 pin 4, 25Refer to “TUNER MODULE”CDTunerCheck the IC601 pin2Refer to “IC404 Troubleshooting”MIC- 2- 12 -Refer to “IC301Troubleshooting”IC301 TroubleshootingIC501 TroubleshootingCheck the power supplying IC301 Pin 17, 46, 72, 90?Refer to

49、“Power Circuit Troubleshooting”Check the P- SENSReplace the X301Check the RESET circuitRefer to “Power Circuit Troubleshooting”Check the Data of IC301 Pin 3, 4(CD TAPE FUNCTION)Replace the IC501Check the pattern of (IC301 & IC501)Check the 5V of IC301 pin26Check the oscillation of X301When power sup

50、plying to IC301 pin11.(High Low High)Replace the IC301Check the power supplying to IC501 pin16Check the CLK Data of IC501 pin 2, 3Check the CONTROLL functionENDYESYESYESYESYESYESYESNONONONONONONO- 2- 13 -IC601 TroubleshootingIC701 TroubleshootingCheck the power supplying to IC601 Pin 1Refer to “Powe