HarmanKardon-HD755-cd-sm维修电路原理图.pdf

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1、Technical Manual The Harman Kardon Model HD755 silver COMPACT DISC PLAYER DANGER: Invisible laser radiation when open and interlock failed or defeated. AVOID DIRECT EXPOSURE TO BEAM. CONTENTS Parts and Service Office 250 Crossways Park Dr., Woodbury, N.Y. 11797 1112-FL8350 P9603 1200 Printed in Hong

2、 Kong 1.LASER BEAM SAFETY PRECAUTIONS . 2 2.CONTROL AND FUNCTIONS . 4 3. SPECIFICATIONS AND FEATURES . 7 4. AUDIO CHARACTERISTICS TEST PROCEDURE . 9 5. CIRCUIT DESCRIPTION .11 6. CRITICAL I.C. SPECIFICATION . 15 7. PART LIST . 41 9. BLOCK DIAGRAM . 54 10. SCHEMATIC DIAGRAMS . 55 11. PCB LAYOUT . 59

3、12. EXPLODED VIEW . 62 13. 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

4、specifications unless otherwise stated. 8. TROUBLE SHOOTING GUIDE . 48 Standby RadioFans.CN HD755 LASER BEAM SAFETY PRECAUTIONS CLASS 1 LASER PRODUCT CAUTION Invisible laser radiation when the unit is open. Do not stare into beam. CAUTION: USE OF ANY CONTROLS, ADJUSTMENT, OR PROCEDURES OTHER THAN TH

5、OSE SPECIFIED HEREIN MAY RESULT IN HAZARDOUS RADIATION EXPOSURE. Do not look directly at the laser beam coming from the pickup or allow it to strike against your skin. This compact disc player uses a pickup that emits a laser beam. The laser beam is emitted from the location shown in the figure. Whe

6、n checking the laser diode, be sure to keep your eyes at least 1 foot away from 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 in hazardous radiation exposu

7、re. 2 HD755 RadioFans.CN SAFETY PRECAUTIONS This symbol is intended to alert the user to the presence of uninsulated dangerous voltage within the products enclosure that may be of sufficient magnitude to consti- tute a risk of electric shock to persons. This symbol is intended to alert the user to t

8、he presence of important operating and maintenance (servicing) instructions in the literature 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 be fully inserted to prevent blade e

9、xposure. Attention: Pour prevenir les chocs electriques ne pas utiliser cetre fiche polarisee avec un prolongateur, une prise de courant ou une au- tre sortie de courant, sauf si les lames prevent etre inserees a fond-sans en laisser aucune partie a decouvert. HANDLING LASER PICKUP The laser diode i

10、n the optical system of this player can be damaged by electrostatic discharge from your clothes or your body. Proper electrostatic grounding for service personal is required during servicing. BEFORE REPAIRING THE COMPACT DISC PLAYER Preparation Human Body Grounding: Many of the components used in th

11、is compact disc player, including the laser pickup, are sensitive to electrostatic 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 el

12、ectrical components with your clothing. Workbench and Tool Grounding: A properly-grounded electroconductive plate (1Mohm) or metal sheet should be fitted to the workbench surface. Tools and instruments (such as soldering irons and scopes) should be grounded to prevent AC leakage. Note: Laser diodes

13、are so susceptible to damage from static electricity that, even if a static discharge does not ruin a diode, it can shorten its life or cause it to work improperly. WARNING To prevent fire or shock hazard, do not expose the unit to rain or moisture. 3 HD755 RadioFans.CN HD755 ? Power: Press this swi

14、tch to apply power to the HD750. Then the Status-Mode Indicator 1 will turn green, the Information Display Cwill illuminate and all trays will be checked automatically for discs. Press the switch again to turn the unit off; the Status-Mode Indicator 1will turn amber, indicating that the unit is in S

15、tandby. When the HD750 is connected to a switched AC outlet, such as those found on the back of many audio products, and the AC outlet will be turned on, the unit will turn to Standby mode only. 1 Status-Mode Indicator: When the HD750 is in the On mode, this indicator will glow green. When the unit

16、is off, the indicator will glow amber, indicating that the unit is still connected to AC power. 2 Headphones Jack: Connect a set of stan- dard headphones to this jack for private listening. 3 Headphones Level Control: Turn this knob to increase or decrease the volume level for headphones connected t

17、o the HD750s Headphones Jack2.Note that changing this level will not change the sound level for the units main output,as that remains constant. 4 CD Drawer: This drawer holds the discs that will be played. Press the Open/Close but- ton 5to open the drawer so that discs may be inserted. 5 Open/Close:

18、 Press this button to open or close the disc drawer. DO NOT push the drawer to close it or damage to the transport mecha- nism may result. 6Search: Press one side of this button to search forward or the other side of the button to search backwards through a disc to locate a particular portion of the

19、 disc being played. 7Skip: Press the right side of this button to move to the next track fl or the left side of the button to move back to the previous track fi on the disc being played. 8Stop: Press this button to stop the disc cur- rently being played. During programming functions, this button is

20、also used to exit the pro- 9Play/Pause Button: Press this button to start the playback of a CD.If the CD drawer is open,pressing this button will automatically close the drawer. When a disc is playing press this button once to momentarily stop a disc. When the button is pressed again, the disc will

21、resume play at the point it was stopped. A Intro Button: Press this button to put the HD750 in teh Intro Scan mode. When you press the button, the unit will play the first 10 sec of each track on the disc, and then move to the next track. Press the button again to defeat the function and continue fu

22、ll play of the current track. B HDCD Indictaor: The LED will light automatically when a CD with HDCD encoding is playing. No further action 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 behi

23、nd this window receives commands from the remote control. Keep this area clear if you wish to use the HD750 with a remote control. Front Panel Controls ? 1 2 3 4 5 6 7 8 9 A B C D Power Switch Status Mode Indicator Headphones Jack Headphones Level Control CD Drawer Open/Close Button Search Button Sk

24、ip Button Stop Button Play/Pause Button Repeat Button HDCD Indicator Information Display Remote Sensor Important Note: When the unit is turned off (to Standby), pressing any button on the front panel will turn the unit on. When Play 5 10 on the front or on the remote is pressed, the unit will automa

25、tically turn on and start playing the disc actually loaded. gram mode. Program Button: This button is used to program the playback of a disc in a particular order. Repeat Button: Press this button once to repeat only the tracfk currently being played. Press it again to continually repeat all tracks

26、on a disc. Random Button: Press this button to have all of the tracks played in a random order. Program Button: This button is used to program the playback of a disc in a particular order. 4 Standby 1263487 151617910131 41 211 5 15 16 17 15 16 17 Program Button Random Button Repeat Button HD755 Rear

27、 Panel Connections ? ? ? ? ? Digital Output Audio Outputs Remote Control Output Remote Control Input AC Power Cord 2 3 1 5 4 ? AC Power Cord: Connect this plug to an AC outlet, if the outlet is switch controlled, make certain that the switch is in the ON position. ?Aud iio Outputs: Connect these jac

28、ks to the CD audio inputs of your receiver, surround processor or preamplifier. Digital Output: Connect this jack to the coaxial digital input of an external digital-to-analog converter for direct access to the digital signals of HD750, DO NOT connect this jack to the standard audio inputs of any de

29、vice. ? ? Remote Control Input: Connect the out- put of a remote infrared sensor or the remote control output of another compatible Harman Kardon product.This will enable the remote con- trol system to operate even when the front panel Remote Sensor is blocked. It will also allow use of the HD750 wi

30、th optional, external control systems. ? Remote Control Output: Connect this jack to the input of another compatible Harman Kardon remote controlled device to have the remote sensor on the HD750 provide signals to other products. 5 HD755 Remote Control Functions 1 3 4 5 2 6 7 8 9 11 10 12 13 14 15 1

31、6 17 Display Button Numeric Controls Clear Button Search Buttons Skip Buttons Stop Button Play Button Program Button Pause Button Check Button Time Button Random Button Repeat Button A B Button Power On Power Off Open/ Close Button 1 3 4 5 2 6 7 8 9 11 10 12 13 14 15 16 17 6 HD755 HD750 Preliminary

32、Production Specification Version 0.1 GENERAL 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, EN61000-3-2,

33、 EN61000-3-3, EN55022 ii. CE (LVD EN60065) iii. HDCD 7. Sound ProcessorHDCD 8. CD Servo SystemDigital Servo, Auto Alignment AUDIO SPECIFICATION Typical Limit Output Level 1KHz 0dB (no HDCD)1.0 Vrms+-1dB Output Level 1KHz 0dB (HDCD output)2.0Vrms +- 2dB Frequency Response 20Hz20KHz reference+0-1dB+0.

34、5-1.5dB THD 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)96dB96dB Dynamic Range95dB95dB Channel Separation 1KHz 0dB(30KHz Filter)94dB90dB Channel Balance+-0.5dB+-1.5dB De-emphasis (5KHz,16KHz)+-

35、0.5dB+-1.5dB Headphone output specification under 32 ohm load Maximum Headphone Output Level 1KHz 0dB1.5Vp-p+-0.2V Frequency Response (2020KHz)+-1dB+-1.5dB THD 2020KHz 0dB (30KHz Filter)0.1%0.2% Test Disc Specification TypicalLimit Black Dot TCD 725B 1000um600um HD755 7 HD750 Preliminary Production

36、Specification Test Disc Specification TypicalLimit Black Dot TCD 725B 1000um600um Interruption MCD-131900um600um Finger print75um65um Vertical Deviation MCD-1510.92mm 0.92mm Eccentricity TCD 712140um140um 8cm test disc TCD 783Last TrackLast Track Access Time 1st to last track YEDS184 sec10 sec HD755

37、 8 HD755 Audio Characteristics Test Procedure Test Equipment 1. 3346 CD Player Evaluating Filter x 2 (NF Electronic Instrument) 2. VP7722 Panasonic Audio Analyzer 3. Sony YEDS18 Test CD disc Procedure Equipment Setup 1. The audio output of the CD player under test is connected to the CD filter L for

38、 CDRW disc VGCTRL is set to VREF2 - 0.75 V. At the same time, the focus gain is changed too. AB CD F PDIC E 32 31 282130 23 2524 GCTRL To Focus System TBAL Subtraction R10 TEN C8 TEOUT VGCTRL C2 C15C5 R5 VREF1VREF2 R15 R14 VTBAL 11 HD755 Focus System The focus error output of A, B, C and D are given

39、 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 voltage VFBAL from Pin 30. VFBAL varies with reference to the center voltage VREF2 (=1.65 V) within 0.5 V. The foc

40、us 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, the tracking gain is changed too. AB CD F PDIC E 36 34 28292726 GCTRL FBAL Subtraction R7 FEN C4 FEOUT VGCTRL C2 C3 R6 VFBAL 35 33

41、35 C35 C47R27 R21 R20 12 HD755 RF, EQ, AGC The signals A, B, C and D input from PDIC are composed into the RF signal by the RF Addition Amp, then output from RFOUT of Pin 5. This Amp is designed so that RFOUT is about 0.5 Vp-p for normal CD disc (about 0.4 Vp-p for CDR and 0.12 Vp-p for CDRW). RF si

42、gnal from Pin 5 is then input to the AGC block through the EQ block (the EQ characteristic is fixed for single speed operation in this design). It is then gain-controlled and output to Pin 10 ARF. The AGC block maintains the output level of ARF to about 1.0Vp-p for all types of disc. C38 connected t

43、o Pin 9 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 is changed in accrodance with the voltage of GCTRL Pin 28. The ENV detection block de

44、tects the fluctuation of the 3T-composition in the RF signal which is needed for focus balance adjustment. C39 connected to Pin 11 forms a filter for detecting the signal fluctuation. The ENV output signal from Pin 12 is filtered by C29. 36 34 GCTRL VGCTRL C2 35 33 35 C35 C47R27 R21 R20 6 EQAGC 8910

45、17 RF DETECTION ENV DETECTION 1112 VCC1 ARF VCC1 NRFDET ENV 28 C29 C39 C28 C38 RFOUT 13 HD755 APC The laser diode has large negative temperature characteristic in its optical output when driven with a constant current on laser diode. Therefore, the output on processing monitor photo diode, must be a

46、 controlled current for getting regular output power, thus the APC (Auto Power Control) circuit is composed. Reference Power Supply A reference power supply for servo is built-in. The current capacity of the reference supply is about 3 mA. VREF1 = 1/2 VCC1 = 2.5 V VREF2 = 1/2 VCC2 = 1.65 V where VCC

47、1 = 5 V and VCC2 = 3.3 V 19 LD 2 1 VCC1 PD 170mV LASER UNIT C33 R18 Q1 LDON 20 R VCC1 R R/2 VREF1 22 R VCC2 R R/2 VREF2 14 HD755 HD755 Overview The MN662790RSA is a CD signal processing LSI that, on a single chip, combines optics servos for the CD player (focus, tracking, and traverse servos), digit

48、al signal processing (EFM demodulation and error correction), digital servo processing for the spindle motor, digital filter, and D/A converter, so thus covers all signal processing functions from the heads RF amplifier onward. Features (Optics servo) Focus, tracking, and traverse servos Automatic adjustment functions for FO/TR gain, FO/TR offset, and FO/TR balance Built-in