HarmanKardon-HD755-cd-sm维修电路原理图.pdf

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1、Technical ManualThe Harman KardonModel HD755 silverCOMPACT DISC PLAYERDANGER: Invisible laser radiation when open and interlock failed or defeated.AVOID DIRECT EXPOSURE TO BEAM.CONTENTSParts and Service Office250 Crossways Park Dr., Woodbury, N.Y. 117971112-FL8350 P9603 1200 Printed in Hong Kong1.LA

2、SER BEAM SAFETY PRECAUTIONS . 22.CONTROL AND FUNCTIONS . 43. SPECIFICATIONS AND FEATURES . 74. AUDIO CHARACTERISTICS TEST PROCEDURE . 95. CIRCUIT DESCRIPTION .116. CRITICAL I.C. SPECIFICATION . 157. PART LIST . 419. BLOCK DIAGRAM . 5410. SCHEMATIC DIAGRAMS . 5511. PCB LAYOUT . 5912. EXPLODED VIEW .

3、6213. PACKING DRAWING . 63* Harman/ kardon continually strives to improve its products. The HD750 Compact Disc Player design and specifications are subject to change and may differ from the published specifications and descriptions, but will always equal or exceed the original specifications unless

4、otherwise stated.8. TROUBLE SHOOTING GUIDE . 48StandbyRadioFans.CN 收音机爱 好者资料库HD755LASER BEAM SAFETY PRECAUTIONSCLASS 1 LASER PRODUCTCAUTIONInvisible laser radiation when the unit is open.Do not stare into beam.CAUTION: USE OF ANY CONTROLS, ADJUSTMENT, ORPROCEDURES OTHER THAN THOSE SPECIFIED HEREINMA

5、Y RESULT IN HAZARDOUS RADIATION EXPOSURE.Do not look directly at the laser beamcoming from the pickup or allow it tostrike against your skin.This compact disc player uses a pickup that emits a laser beam. The laser beam is emitted from thelocation shown in the figure. When checking the laser diode,

6、be sure to keep your eyes at least 1 foot awayfrom the pickup lens when the diode is turned on. Do not look directly at the laser beam.CAUTION:Using controls and adjustment, or doing procedures other than those specified herein, may result inhazardous radiation exposure.2HD755RadioFans.CN 收音机爱 好者资料库

7、SAFETY PRECAUTIONSThis symbol is intended to alert the user tothe presence of uninsulated dangerousvoltage within the products enclosure thatmay be of sufficient magnitude to consti-tute a risk of electric shock to persons.This symbol is intended to alert the user tothe presence of important operati

8、ng andmaintenance (servicing) instructions in theliterature accompanying the appliance.Caution:To prevent electric shock do not use this(polarized) plug with an extension cord, recep-tacle or other outlet unless the blades can befully inserted to prevent blade exposure.Attention: Pour prevenir les c

9、hocs electriques ne pasutiliser cetre fiche polarisee avec unprolongateur, une prise de courant ou une au-tre sortie de courant, sauf si les lames preventetre inserees a fond-sans en laisser aucunepartie a decouvert.HANDLING LASER PICKUPThe laser diode in the optical system of this player can be dam

10、aged by electrostatic discharge fromyour clothes or your body. Proper electrostatic grounding for service personal is required during servicing.BEFORE REPAIRING THE COMPACT DISC PLAYERPreparationHuman Body Grounding:Many of the components used in this compact disc player, including the laser pickup,

11、 are sensitive toelectrostatic discharge. Service personal should be grounded with an electrostatic armband (1 Mohm).Caution:Static charge on clothing does not escape through a body grounding wrist band.Be careful not to contact the pickup or electrical components with your clothing.Workbench and To

12、ol Grounding:A properly-grounded electroconductive plate (1Mohm) or metal sheet should be fitted to the workbenchsurface. Tools and instruments (such as soldering irons and scopes) should be grounded to prevent ACleakage.Note: Laser diodes are so susceptible to damage from static electricity that, e

13、ven if a static discharge doesnot ruin a diode, it can shorten its life or cause it to work improperly.WARNINGTo prevent fire or shock hazard, do notexpose the unit to rain or moisture.3HD755HD755? Power: Press this switch to apply power tothe HD750. Then the Status-Mode Indicator1 will turn green,

14、the Information DisplayCwill illuminate and all trays will be checkedautomatically for discs. Press the switch again toturn the unit off; the Status-Mode Indicator1will turn amber, indicating that the unit is inStandby. When the HD750 is connected to aswitched AC outlet, such as those found on theba

15、ck of many audio products, and the AC outletwill be turned on, the unit will turn to Standbymode only.1 Status-Mode Indicator: When the HD750 is in the On mode, this indicator willglow green. When the unit is off, the indicatorwill glow amber, indicating that the unit is stillconnected to AC power.2

16、 Headphones Jack: Connect a set of stan-dard headphones to this jack for private listening.3 Headphones Level Control: Turn this knobto increase or decrease the volume level forheadphones connected to the HD750sHeadphones Jack2.Note that changing thislevel will not change the sound level for theunit

17、s main output,as that remains constant.4 CD Drawer: This drawer holds the discsthat will be played. Press the Open/Close but-ton 5to open the drawer so that discs may beinserted.5 Open/Close: Press this button to open orclose the disc drawer. DO NOT push the drawerto close it or damage to the transp

18、ort mecha-nism may result.6Search: Press one side of this button tosearch forward or the other side of thebutton to search backwards through adisc to locate a particular portion of the discbeing played.7Skip: Press the right side of this button tomove to the next track flor the left side ofthe butto

19、n to move back to the previous trackfion the disc being played.8Stop: Press this button to stop the disc cur-rently being played. During programmingfunctions, this button is also used to exit the pro-9Play/Pause Button: Press this button tostart the playback of a CD.If the CD drawer isopen,pressing

20、this button will automaticallyclose the drawer. When a disc is playing pressthis button once to momentarily stop a disc.When the button is pressed again, the disc willresume play at the point it was stopped.A Intro Button: Press this button to put the HD750in teh Intro Scan mode. When you press the

21、button, theunit will play the first 10 sec of each track on the disc, andthen move to the next track. Press the button again to defeat the function and continue full play of the current track.B HDCD Indictaor: The LED will light automaticallywhen a CD with HDCD encoding is playing. No further action

22、 is needed to enjoy the benefits of HDCD.C Information Display: This display provides details about the operation of the HD750.D Remote Sensor: The sensor behind thiswindow receives commands from the remotecontrol. Keep this area clear if you wish to usethe HD750 with a remote control.Front Panel Co

23、ntrols?123456789ABCDPower SwitchStatus Mode IndicatorHeadphones JackHeadphones Level ControlCD DrawerOpen/Close ButtonSearch ButtonSkip ButtonStop ButtonPlay/Pause ButtonRepeat ButtonHDCD IndicatorInformation DisplayRemote SensorImportant Note: When the unit is turned off(to Standby), pressing any b

24、utton on the frontpanel will turn the unit on. When Play 5 10on the front or on the remote is pressed, the unitwill automatically turn on and start playing the discactually loaded.gram mode. Program Button: This button is used toprogram the playback of a disc in a particularorder. Repeat Button: Pre

25、ss this button once torepeat only the tracfk currently being played. Pressit again to continually repeat all tracks on a disc. Random Button: Press this button tohave all of the tracks played in a random order. Program Button: This button is used toprogram the playback of a disc in a particularorder

26、.4Standby1263487151617910131 41 2115151617151617Program ButtonRandom ButtonRepeat ButtonHD755Rear Panel Connections?Digital OutputAudio OutputsRemote Control OutputRemote Control InputAC Power Cord2 3 1 54? AC Power Cord: Connect this plug to an AC outlet, if the outlet is switch controlled, makecer

27、tain that the switch is in the ON position.?Aud iio Outputs: Connect these jacks to the CDaudio inputs of your receiver, surround processor orpreamplifier. Digital Output: Connect this jack to the coaxialdigital input of an external digital-to-analogconverter for direct access to the digital signals

28、 ofHD750, DO NOT connect this jack to the standardaudio inputs of any device.? ? Remote Control Input: Connect the out-put of a remote infrared sensor or the remotecontrol output of another compatible HarmanKardon product.This will enable the remote con-trol system to operate even when the front pan

29、elRemote Sensor is blocked. It will also allowuse of the HD750 with optional, external controlsystems.? Remote Control Output: Connect thisjack to the input of another compatible HarmanKardon remote controlled device to have the remote sensor on the HD750 provide signals toother products.5HD755Remot

30、e Control Functions1345267891110121314151617Display ButtonNumeric ControlsClear ButtonSearch ButtonsSkip ButtonsStop ButtonPlay ButtonProgram ButtonPause ButtonCheck ButtonTime ButtonRandom ButtonRepeat ButtonA B ButtonPower OnPower OffOpen/ Close Button13452678911101213141516176HD755HD750 Prelimina

31、ry Production Specification Version 0.1GENERAL INFORMATION 1. Power ConsumptionOperating 18W; Standby 5W 2. Power Super 230V AC 50Hz 3. Dimensions440 x 130 x 386mm 4. Product OutlookRefer to attached diagram 5. Remote Unit harman/kardon remote code 6. Compliance Requirement i EMC EN55013, EN61000-3-

32、2, EN61000-3-3, EN55022ii. CE (LVD EN60065) iii. HDCD 7. Sound ProcessorHDCD 8. CD Servo SystemDigital Servo, Auto AlignmentAUDIO SPECIFICATIONTypical LimitOutput Level 1KHz 0dB (no HDCD)1.0 Vrms+-1dBOutput Level 1KHz 0dB (HDCD output)2.0Vrms +- 2dBFrequency Response 20Hz20KHz reference+0-1dB+0.5-1.

33、5dBTHD 1KHz 0dB (30KHz Filter)0.006%0.01%THD 1KHz 0dB (no any filter)0.03%0.08%THD 20Hz20KHz 0dB (30KHz Filter)0.04%0.05%S/N 1KHz 0dB A-weighted (A Filter)96dB96dBDynamic Range95dB95dBChannel Separation 1KHz 0dB(30KHz Filter)94dB90dBChannel Balance+-0.5dB+-1.5dBDe-emphasis (5KHz,16KHz)+-0.5dB+-1.5dB

34、Headphone output specification under 32 ohm loadMaximum Headphone Output Level 1KHz 0dB1.5Vp-p+-0.2VFrequency Response (2020KHz)+-1dB+-1.5dBTHD 2020KHz 0dB (30KHz Filter)0.1%0.2%Test Disc SpecificationTypicalLimitBlack Dot TCD 725B 1000um600umHD7557HD750 Preliminary Production SpecificationTest Disc

35、 SpecificationTypicalLimitBlack Dot TCD 725B 1000um600umInterruption MCD-131900um600umFinger print75um65umVertical Deviation MCD-1510.92mm 0.92mmEccentricity TCD 712140um140um8cm test disc TCD 783Last TrackLast TrackAccess Time 1st to last track YEDS184 sec10 sec HD7558HD755Audio Characteristics Tes

36、t ProcedureTest Equipment1. 3346 CD Player Evaluating Filter x 2 (NF Electronic Instrument)2. VP7722 Panasonic Audio Analyzer3. Sony YEDS18 Test CD discProcedureEquipment Setup1. The audio output of the CD player under test is connected to the CD filter L& R inputs.2. The outputs from the filter are

37、 connected to the Audio Analyzer.Check the output Voltage1. Set the mode of the filter to THRU2. Set the mode of Audio Analyzer to LEVEL mode3. Select track 2 of the test disc and play the CD disc4. The output voltage and gain of the R & L channels are taken by pressingthe respective buttons on the

38、control board of Audio Analyzer.Frequency Response1. Set the mode of the filter to reference level mode.2. Select the track 3, 4, 5, and 6 of the test disc and run it under Play mode.3. Check the output of the R & L ChannelsTotal Harmonic Distortion1. Set the mode of the filter to DIST/CH-SP mode2.

39、Set the audio analyzer to DIST mode.3. Set the unit of the audio analyzer to % mode4. Select the track 2, 4, and 5 on the test disc and run them under PLAYmode5. Check the % of each R & L channels9HD755Signal to Noise Ratio1. Set the mode of the filter to S/N mode2. Play track 2 of the test disc3. T

40、he unit of the audio analyzer is set to dB mode4. Press the S/N key on the control panel of the audio analyzer5. Play track 76. Measure the data of S/N ratioDynamic Range1. Set the mode of the filter to D-Range mode2. Set the audio analyzer to DIST Mode3. Set the unit of the audio analyzer to dB mod

41、e4. Play track 17of the test disc5. The dynamic range should be |A| + 60dBChannel Separation1. Set the mode of the filter to DIST/CH-SP mode2. Set the audio analyzer to LEVEL mode3. Play the tracks 8, 9, 10 & 114. The measured results is the difference between L & R channelDe-emphasis1. Press the TH

42、RU button of the CD filter2. Play the track 2 of the test disc3. Press the Relative Level and make it ON4. Select the track 12 and 13 and measure the L & R channels value10FUNCTION DESCRIPTIONTracking SystemThe tracking error output of E and F is given to Pin 25 (TEOUT). C8 is required foroscillatio

43、n-proof. R10 is chosen such that TEOUT of Pin 25 become 1.4Vp-p.During alignment procedure, the DSP IC (MN662790) will adjust the tracking balancevoltage VTBAL from Pin 31. VTBAL varies with reference to the center voltage VREF2 (=1.65 V)within 0.5 V.The tracking gain will change according to the ty

44、pe of disc. For normal disc or CDR disc,VGCTRL is set to VREF2; for CDRW disc VGCTRL is set to VREF2 - 0.75 V. At the same time, thefocus gain is changed too.ABCDFPDICE3231282130232524GCTRLTo Focus SystemTBALSubtractionR10TENC8TEOUTVGCTRLC2C15C5R5VREF1VREF2R15R14VTBAL11HD755Focus SystemThe focus err

45、or output of A, B, C and D are given to Pin 27. C4 is required for oscillation-proof. R7 is set such that FEOUT of Pin 27 becomes 1.46 Vp-p.During alignment procedure, the DSP IC (MN662790) will adjust the focus balance voltageVFBAL from Pin 30. VFBAL varies with reference to the center voltage VREF

46、2 (=1.65 V) within0.5 V.The focus gain will change according to the type of disc. For normal disc or CDR disc,VGCTRL is set to VREF2; for CDRW disc VGCTRL is set to VREF2 - 0.75 V. At the same time, thetracking gain is changed too.ABCDFPDICE363428292726GCTRLFBALSubtractionR7FENC4FEOUTVGCTRLC2C3R6VFB

47、AL353335C35C47R27R21R2012HD755RF, EQ, AGCThe signals A, B, C and D input from PDIC are composed into the RF signal by the RFAddition Amp, then output from RFOUT of Pin 5. This Amp is designed so that RFOUT isabout 0.5 Vp-p for normal CD disc (about 0.4 Vp-p for CDR and 0.12 Vp-p for CDRW).RF signal

48、from Pin 5 is then input to the AGC block through the EQ block (the EQcharacteristic is fixed for single speed operation in this design). It is then gain-controlledand output to Pin 10 ARF. The AGC block maintains the output level of ARF to about1.0Vp-p for all types of disc. C38 connected to Pin 9

49、is for the AGC loop filter.The RF Detection block detects the amplitude of the RF signal inputted from the EQ block.Inputted RF signal is detected after passing through a high-pass filter. Detection level ischanged in accrodance with the voltage of GCTRL Pin 28.The ENV detection block detects the fl

50、uctuation of the 3T-composition in the RF signalwhich is needed for focus balance adjustment. C39 connected to Pin 11 forms a filter fordetecting the signal fluctuation. The ENV output signal from Pin 12 is filtered by C29.3634GCTRLVGCTRLC2353335C35C47R27R21R206EQAGC891017RFDETECTIONENVDETECTION1112