LG-LHT250SC-cdkr-sm 维修电路原理图.pdf

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1、DVD/CD & KARAOKE RECEIVERSERVICE MANUALMODELS : LH-T250SC(LH-T250SC) Speakers: LHS-25SCS, LHS-25SCW MODELS : LH-T252SC(LH-T250SC) Speakers: LHS-25SCS, LHS-25SCW MODELS : LH-T250SC/LH-T252SCSERVICE MANUALRadioFans.CN 收音机爱 好者资料库1-1CONTENTSSECTION 1.GENERAL SERVICING PRECAUTIONS . . . . . . . . . . . .

2、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 ESD PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4 SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3、. . . . . . . . . . . . .1-5SECTION 2. AUDIO PART AUDIO TROUBLESHOOTING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4 SCHEMATIC

4、DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6 WIRING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18 PRINTED CIRCUIT DIARGAMS . . . . . . . . . . . . . . . . . .

5、. . . . . . . . . . . . . . . . . . . . . . . . . . 2-20SECTION 3.DVD & AMP PART ELECTRICAL TROUBLESHOOTING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1 DVD PART SCHEMATIC DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-22SE

6、CTION 4. EXPLODED VIEWS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-1SECTION 5. SPEAKER PART . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-1SECTION 6. REPLACEMENT PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-1Ra

7、dioFans.CN 收音机爱 好者资料库1-2SERVICING 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.2. Repair notes1) Th

8、e 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 be an operational malf

9、unction 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!Absolutely never permit la

10、ser 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 lens). The lens is held by a

11、 delicate spring. When cleaning the lens surface, therefore, a cot-ton 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. (Do not use any other liquid

12、cleaners, because they will damage the lens.) Take care not to use too muchof this alcohol on the swab, and do not allow the alcohol to get inside the pick-up.Storage in conductive bagDrop impactNEVER look directly at the laser beam, and dont let contact fingers or other exposed skin.MagnetHow to ho

13、ld the pick-upConductive SheetCotton swabPressurePressureSECTION 1. GENERAL1-3NOTES REGARDING COMPACT DISC PLAYER REPAIRS1. Preparations1) Compact disc players incorporate a great many ICs as well as the pick-up (laser diode). These componentsare sensitive to, and easily affected by, static electric

14、ity. 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 components. Care must betaken, therefore, to avoid repair or storage where the temperat

15、ure 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 equipment, measuring instruments and tools must be grounded.3) The workbench should b

16、e 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 soldering iron should be grounded.5)

17、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 should NEVER be directly facing the eyes

18、 or bare skin.Resistor(1 Mohm)ConductiveSheetResistor(1 Mohm)Armband1-4ESD 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

19、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 static electricity.1. Immediately before handling any semiconductor component or semico

20、nductor-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. Afte

21、r removing an electrical assembly equipped with ESD devices, place the assembly on a conductive surfacesuch 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 sol

22、der 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 charges sufficient to damage ESDdevices.6. Do not remove a replacement ESD device from

23、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 conductive materials).7. Immediately before removing the protective material from the leads o

24、f 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 ALL OTHERSAFETY PRECAUTIONS.8. Minimize bodily motions when handing unpackaged replacement

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

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

27、T SAFETY INFORMATION IN SERVICELITERATURE.1-5GENERALPower supply Refer to main labelPower consumption Refer to main labelMass 2.5 kgExternal dimensions (W x H x D) 360 x 56 x 310 mmOperating conditions Temperature: 5C to 35C, Operation status: HorizontalOperating humidity 5% to 85%CD/DVDLaser Semico

28、nductor laser, wavelength 650 nmSignal system PAL 625/50, NTSC 525/60Frequency response (audio) 140 Hz to 20 kHzSignal-to-noise ratio (audio) More than 75 dB (1 kHz, NOP-3dB, 20 kHz LPF/A-Filter)Dynamic range (audio) More than 80 dBHarmonic distortion (audio) 0.5 % (1 kHz, at 12W position) (20 kHz L

29、PF/A-Filter)Video output 1.0 V (p-p), 75 , negative sync., RCA jackTUNERFMTuning Range 87.5 - 108.0 MHz or 65.0 - 74.0 MHz, 87.5 - 108.0 MHzIntermediate Frequency 10.7 MHzSignal-to Noise Ratio 60 dB (Mono)Frequency Response 140 - 10,000 HzAM MWTuning Range 522 - 1,620 kHz or 520 - 1,720 kHzIntermedi

30、ate Frequency 450 kHzAMPLIFIERSurround modeFront: 30W + 30W (THD 10 %)Centre*: 30WSurround*: 30W + 30W (6 at 1 kHz, THD 10 %)Subwoofer*: 70W (8 at 30 Hz, THD 10 %)Outputs MONITORMIC Jacks (3.5mm) (KARAOKE MODEL ONLY)SPEAKERSSatellite Speaker (LHS-25SCS) Passive Subwoofer (LHS-25SCW)Type 1 Way 1 Spea

31、ker 1 Way 1 SpeakerImpedance 6 8 Frequency Response 160 - 20,000 Hz 65 - 1,500 HzSound Pressure Level 84 dB/W (1m) 82 dB/W (1m)Rated Input Power 30W 70WMax. Input Power 60W 140WNet Dimensions (W x H x D) 92 x 115 x 80 mm 160 x 350 x 280 mmNet Weight 0.5 kg 3.18 kg(* Depending on the sound modesettin

32、gs and the source, theremay be no sound output.)SPECIFICATIONS2-1SECTION 2. AUDIO PARTAUDIO TROUBLESHOOTING GUIDE1. POWER SUPPLY CIRCUIT2-22. FRONT CIRCUIT (1/2)PIN3PIN4PIN9: -27.5 FL-: -32.4 VKK: -23.7 FL+: +5.0CN902CN9022-33. FRONT CIRCUIT (2/2)2-42-5BLOCK DIAGRAM2-62-7SCHEMATIC DIAGRAMS 1. POWER

33、SCHEMATIC DIAGRAMABCDEFGHIJKLMNOPQRST2-82-92. MICOM SCHEMATIC DIAGRAMABCDEFGHIJKLMNOPQRST2-102-113. FRONT SCHEMATIC DIAGRAMABCDEFGHIJKLMNOPQRST2-122-134. DSP& SCHEMATIC DIAGRAMABCDEFGHIJKLMNOPQRST2-142-155. DSP SCHEMATIC DIAGRAMABCDEFGHIJKLMNOPQRST2-162-176. KARAOKE SCHEMATIC DIAGRAM(KARAOKE MODE

34、L ONLY)ABCDEFGHIJKLMNOPQRST2-182-19WIRING DIAGRAM2-202-21PRINTED CIRCUIT BOARD DIAGRAMS1. MAIN/DVD P.C. BOARD DIAGRAM (TOP)2-222-232. MAIN/DVD P.C. BOARD DIAGRAM (BOTTOM)2-242-253. FRONT P.C. BOARD (TOP)2-262-274. SMPS P.C. BOARD 5. KARAOKE P.C. BOARD (KARAOKE MODEL ONLY)3-1ELECTRICAL TROUBLESHOOTIN

35、G GUIDE1. System operation flowPower OnNoYesYesYesNoNoNoShow LOGOTray Closed?Tray Close to Closed positionSLED Moves to Inner PositionRecieveOPEN/ CLOSEKey?ReceiveCLOSE Key?1. Stop Playback & Open Tray2. Display tray open message & LOGO1. Execute Pressed Key & IR Key2. Systemoperati on Routi ne Loop

36、1. Judge whether have disc and disc type2. Jump to related disc reading procedureSLED at InnerSide?1. 8082 initializes SERVO, DSP & RISC registers2. Write RISC code to SDRAM3. Reset RISCSECTION 3. DVD & AMP PART3-22. Test & debug flowTESTCheck the POWER PARTNoYesNoYesNoNoYesYesCheck the POWER PARTCh

37、eck the regulators or diode(D501).1. Check 27MHz system clock.2. Check systemreset circuit.3. Check FLASH R/Wenable signal PRD, RWR.4. Check FLASH Memory related circuit.Check theAC Vol tagePower PCBA (110Vor 220V)Switch on the Power PCBAIs theDC Voltageoutputs OK?(-34V,-9V,36V,5.6V,5V,8V,9V,2.5V,3.

38、3V)Is 3.3V and 5V DCoutputs normal on mainPCBA?UpdateFLASH(IC500)successfully?Replace FLASH( IC500)A3-3A, 115.3-4B3-5CES6698.ES6698.ES6698.3-6D3-7ECheck connection between IC300 ABCK, ALRCK,ASDATCheck the related circuit of PWM.(Check Audio out Pins52, 54, 55, 59,62, 68NormalPWM IC out?(IC300)PWM IC

39、received correct datastream?Check Digital Amp circuit(IC301, IC302)3-83. AUDIO -COM Circuit(DVD & AMP)YESDoes CD/DVD appearat FLD?Does CD/DVD appearat FLD?OKDoes Loading appearat FLD?POWER ONYESYESYESDoes no Dise or Timeappear at FLD?NONONONONONONONODoes it appear DVD Errorat FLD?Refer to SMPS.Refer

40、 to oscillator Circuit.Check IC101 ResetWaveform.Check 3.3V line.Check Power sectionCircuit.NOCheck power part of MainB/D.Check oscillator of X101.Check if IC101 Pin80is high.Check if IC101 Pin32, 51,80 are high(5V).Check if IC101 Pin96is high.Replace IC101.NONOCheck if DVD an AudioMicom Insert is O

41、K.Check Power.YESCheck DVD Module.YESCheck SMPS.YESYESYESYESYESYESYES3-9DETAILS AND WAVEFORMS ON SYSTEM TEST AND DEBUGGING1. SYSTEM 27MHz CLOCK,RESET,FLASH R/W SIGNAL1) ES6698FD main clock is at 27MHz(X501)3.8V, 27MHzFIG 1-12) ES6698FD reset is high active.PWR_CTL(SYSTEM -COM)IC501 PIN83)5.2VAPower

42、Cord inM_RESET(IC501 PIN 207)URST(IC501 PIN 188)FIG 1-23-102. SDRAM CLOCK1) ES6698FD main clock is at 27MHz(X501)(IC503 PIN 38)DCLK = 93MHz, Vp-p=2.2, Vmax=2.7VFIG 2-14) Flash R/W enable signal during download(Downloading)FRD(IC500 PIN 28)FWR(IC500 PIN 11)FIG 1-43-113. TRAY OPEN/CLOSE SIGNAL1) Tray

43、open/close waveformOPEN(PDM03 PIN7)CLOSE(PDM03 PIN8)TROPEN(IC402 PIN 4)TRCLOSE(IC402 PIN 5)FIG 3-12) Tray close waveformOPEN(PDM03 PIN7)CLOSE(PDM03 PIN8)TROPEN(IC402 PIN 4)TRCLOSE(IC402 PIN 5)FIG 3-23-124. SLED CONTROL RELATED SIGNAL (NO DISC CONDITION)FMSO(2.0V/1.4V/1.0V)(IC501 PIN 19)STBY(5V) (IC4

44、01 PIN 50)SL+(4.7V/3.6V/1.9V)(IC404 PIN 12)SL-(5.3V/3.7V/2.5V)(IC404 PIN 11)FIG 4-13) Tray open waveformOPEN(PDM03 PIN7)CLOSE(PDM03 PIN8)TROPEN(IC402 PIN 4)TRCLOSE(IC402 PIN 5)FIG 3-33-135. LENS CONTROL RELATED SIGNAL(NO DISC CONDITION)FOSO(1.5V/1.4V/1.3V)(IC501 PIN 12)F+(4.0V/3.6V/3.2V)(IC404 PIN 1

45、4)F-(4.0V/3.6V/3.2V)(IC404 PIN 13)FIG 5-16. LASER POWER CONTROL RELATED SIGNAL(NO DISC CONDITION)MDI1(0V/180mV)(IC401 PIN 26)LD01(5.0V/3.5V)IC401 PIN 20)LD02(5.0V/3.6V)(IC401 PIN 21)FIG 6-13-14F+(IC404 PIN 14)FE(IC401 PIN 40)RFL(IC401 PIN 19)FIG 7-2 (DVD)7. DISC TYPE JUDGEMENT WAVEFORMSF+(IC404 PIN

46、14)FE(IC401 PIN 40)RFL(IC401 PIN 19)FIG 7-1 (DVD)3-15F+(IC404 PIN 14)FE(IC401 PIN 40)RFL(IC401 PIN 19)FIG 7-3 (CD)F+(IC404 PIN 14)FE(IC401 PIN 40)RFL(IC401 PIN 19)FIG 7-4 (CD)3-16FE(IC401 PIN 40)FOSO(IC501 PIN12)F+(IC404 PIN 14)F-(IC404 PIN 13)FIG 8-2 (CD)8. FOCUS ON WAVEFORMSFE(IC401 PIN 40)FOSO(IC

47、501 PIN12)F+(IC404 PIN 14)F-(IC404 PIN 13)FIG 8-1 (DVD)3-179. SPINDLE CONTROL WAVEFORMS (NO DISC CONDITION)DMSO(1.4V/1.8V)(IC501 PIN 18)SP-(3.6V/2.4V)(IC404 PIN 18)SP+(3.6V/4.8V)(IC404 PIN 17)FIG 9-110. TRACKING CONTROL RELATED SIGNAL(System checking)TE(IC401 PIN 39)TRSO(IC501 PIN 13)T-(IC404 PIN 16

48、)T+(IC404 PIN 15)FIG 10-1(DVD)3-1811. RF WAVEFORMRFOP(2.3V/1.1V)(IC401 PIN 55)RFON(0.8V/2.0V)(IC401 PIN 57)FIG 11-1TE(IC401 PIN 39)TRSO(IC501 PIN 13)T-(IC404 PIN 16)T+(IC404 PIN 15)FIG 10-2(CD)3-1912. ES6698FD VIDEO OUTPUT WAVEFORMS1) Full colorbar signal(COMPOSIT)(IC501 PIN 110)FIG 12-12) Y(IC501 P

49、IN 113)FIG 12-23-201) Audio L/RFIG 13-113. AUDIO OUTPUT FROM PWM IC(IC300 PIN 68, 49)2) Audio related SignalASDAT0(IC501 PIN 117)ABCK(IC501 PIN 123)ALRCK(IC501 PIN 116)ASDATA3FIG 13-23-211) R315 FRONT L2) R310 FRONT R3) R316 REAR4) R324 REAR5) R303 CENTER6) R317 WOOFER14. DVD & AMP WAVEFORMSABCDEFGH

50、IJKLMNOPQRST3-223-23DVD PART SCHEMATIC DIAGRAMS1. DVD MPEG & DSP SCHEMATIC DIAGRAMABCDEFGHIJKLMNOPQRST3-243-252. RF & SERVO SCHEMATIC DIAGRAM3. KARAOKE SCHEMATIC DIAGRAMABCDEFGHIJKLMNOPQRST3-263-27 CABINET AND MAIN FRAME SECTIONA43279300320A44452463A47A46463463463250463463463A26283452A41274274452A50