NAD-C720BEE-rec-sm1 维修电路原理图.pdf

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1、NADSERVICE MANUALC 720BEESTEREORECEIVERC 720BEESTEREORECEIVERRadioFans.CN 收音机爱 好者资料库TABLE OF CONTENTS DESCRIPTION P A G E SERVICE CAUTION.3 REAR PANEL/FRONT PANEL VIEW.4 SPECIFICATIONS.5-7 ALIGNMENT PROCEDURE.6-7 WIRING DIAGRAM8 BLOCK DIAGRAM. .9-15 ALIGNMENT PROCEDURE.16 SCHEMATICS.17-20PCB LAYOUT

2、21-24 SPECIAL FUNCTION/TROUBLE SHOOTING GUIDE.25 ELECTRICAL PARTS LIST.26-34 EXPLODED VIEW.35 EXPLODED VIEW PARTS LIST.36 - 2 -PROTECT IC CHANGE .37 RadioFans.CN 收音机爱 好者资料库SERVICING PRECAUTIONS CAUTION:Before servicing the Stereo Receiver covered by this service data and its supplements and addends,

3、 read and follow the SAFETY PRECAUTIONS. NOTE: if unforeseen circumstances create conflict between the following servicing precautions and any of the safety precautions in this publication, always follow the safety precautions. Remember Safety First: General Servicing Precautions 1. Always unplug th

4、e Stereo Receiver AC power cord from the AC power source before: (1) Removing or reinstalling any component, circuit board, module, or any other assembly. (2) Disconnecting or reconnecting any internal electrical plug or other electrical connection. (3) Connecting a test substitute in parallel with

5、an electrolytic capacitor. Caution: A wrong part substitute or incorrect polarity installation of electrolytic capacitors may result in an explosion hazard. 2. Do not spray chemicals on or near this Stereo Receiver or any of its assemblies. 3. Unless specified otherwise in this service data, clean e

6、lectrical contacts by applying an appropriate contact cleaning solution to the contacts with a pipe cleaner, cottontipped swab, or comparable soft applicator. Unless specified otherwise in this service data, lubrication of contacts is not required. 4. Do not defeat any plug/socket B+ voltage interlo

7、cks with which instruments covered by this service manual might be equipped.5. Do not apply AC power to this Stereo Receiver and/or any of its electrical assemblies unless all solid-state device heat sinks are correctly installed. 6. Always connect test instrument ground lead to the appropriate grou

8、nd before connecting the test instrument positive lead. Always remove the test instrument ground lead last.Insulation Checking Procedure Disconnect the attachment plug from the AC outlet and turn the power on. Connect an insulation resistance meter (500V) to the blades of the attachment plug. The in

9、sulation resistance between each blade of the attachment plug and accessible conductive parts (Note 1) should be more than 1 M-ohm. Note 1: Accessible Conductive Parts including Metal panels, Input terminals, Earphone jacks, etc. Electrostatically Sensitive (ES) Devices Some semiconductor (solid sta

10、te) devices can be damaged easily by static electricity. Such components commonly are called Electrostatically Sensitive (ES) Devices. Examples of typical Es devices are integrated circuits and some field effect transistors and semiconductor chip components. The following techniques should be used t

11、o help reduce the incidence of component damage caused by static electricity. 1. Immediately before handing any semiconductor component or semiconductor-equipped assembly, drain off any electrostatic charge on your body by touching a known earth ground. Alternatively, obtain and wear a commercially

12、available discharging wrist strap device, which should be removed for potential shock reason prior to applying power to the unit under test. 2. After removing an electrical assembly equipped with ES devices, place the assembly on a conductive surface such as aluminum foil, to prevent electrostatic c

13、harge buildup or exposure of the assembly. 3. Use only a grounded-tip soldering iron to solder or unsolder ES devices. 4. Use only an antistatic solder removal device. Some solder removal devices not classified a “anti-static” can generate electrical charges sufficient to damage ES devices. 5. Do no

14、t use freonpropelled chemicals. These can generate electrical charge sufficient to damage ES devices. 6. Do not remove a replacement ES device from its protective package until immediately before you are ready to install it. (Most replacement ES devices are packaged with leads electrically shorted t

15、ogether by conductive foam, aluminum foil, or comparable conductive material). 7. Immediately before removing the protective material from the leads of a replacement ES device, touch the protective material to the chassis or circuit assembly into which the device will be installed. Caution: Be sure

16、no power is applied to the chassis or circuit, and observe all other safety precautions. 8.Minimize bodily motions when handing unpackaged replacement ES devices. (Normally harmless motion such as the brushing together of your clothes fabric or the lifting of your foot from a carpeted floor can gene

17、rate static electricity sufficient to damage an ES device.)- 3 -1&2 FM&AM ANTENNA3. SPEAKER A&B4. SWITCHED AC OUTLET5. AC LINE CORD6. VACATION SWITCH ON/OFF7. SOFT CLIPPING8. SUBW OUT9. MAIN IN10. PRE-OUT11. RECORD OUT/ZONE 212. TAPE IN13. AUX INPUT14. VIDEO INPUT15. CD INPUT16. DISC INPUT17. IR INP

18、UT/OUTPUT18. +12V TRIGGER OUTFRONT PANEL/REAR PANEL- 4 -Power Amplifier SectionCONTINUOUS AVERAGE POWEROUTPUT AT 8 OHMS50W (17dBw) (Minimum RMS power per channel, both channels driven, With no more than the rated distortion)Rated distortion (THD)(20Hz 20kHz)?0.03%Channel Separation?70dB(MAIN IN, 20W

19、 Out at 8?,1k? shorted, 1kHz)Clipping power, 1kHz68W(Maximum continuous power per channel)Dynamic Headroom at 8 ohms3.4dBDynamic power8ohms110W(Maximum short-term power per channel )4ohms160W2ohms210WDamping factor?100Slew factor?50Slew rate?20V/?secT.H.D and SMPTE I.M.?0.03% (Distortion from 250mW

20、to rated output)IHF I.M. (CCIF IM) and T.I.M distortion?0.03% (From 250mW to rated output)Input impedance22k?/470pFInput sensitivity( For 50 Watts out) ?700mVPower amp gain29dBPreamplifier SectionInput Impedance22k?/100pFSPECIFICATIONSNAD C720BEE Stereo ReceiverNote: Specifications are measured in a

21、ccordance with EIAStandard RS-490 (IHF A-202) for amplifiers and ANSI-IEEEStandard 185(1975), i.e. input and converted to equivalent300-ohm values.- 5 -Signal-to-Noise ratio110dB ref 500mV(A-weighted, 1kHz CD In, Pre-Out)Rated distortion (THD)(20Hz 21kHz)?0.03%Channel Separation?70dB2V CD IN, 2V Pre

22、-Out,1k? shorted,1kHzInput Sensitivity320mV for 1V outInput Overload?10VFrequency responsetone defeat+/-0.1dBtone on+/-0.5dBTHD (SUB OUT)?0.03%(2V CD in, 2V SUB out; 50Hz, 80kHz LPF)THD (ZONE 2 OUT)(2V CD IN, 1kHz, 80kHz LPF)?0.03%Frequency Response(SUB OUT)50Hz)?3dB at 100HzOutputsPreamp output imp

23、edance80?Zone2 output impedanceSource Z+ 600?ControlsTreble5dB at 10kHzBass8dB at 100HzPre-in ,Power AMP out,input 2VSignal-to-Noise ratio, A-weighted98dB ref 1 W out(500mV CD in, SPK out, 8?, A weighted)Rated distortion (THD)(20Hz 20kHz)?0.03%Input sensitivity225mV(CD in, SPK out, at rated power, v

24、olume max.)Channel Separation?70dB(CD in, 20W out at 8?, 1k? shorted, 1kHz)Frequency responsetone defeat+/-0.1dBtone on+/-0.5dBUsual sensitivityMono, -30dB THD+N?12dBuVMono, 50 dB S/N?25dBuVTuner FM Section(At 75kHz deviation for AH ; 40kHz for C)- 6 -Capture ratio (at 45 and 65 dBf)?3 dBAM rejectio

25、n (at 65 and 85dBf)?40 dBAlternative channels Selectivity?40 dB(RF400KHz, at 30dB)Image rejection(at usable sensitivity)?70 dBI.F. rejection (at usable sensitivity)?70 dBPilot suppression (1kHz, 60dBu)?55 dBTHDMono, 1kHz, 60dBu?0.8%Stereo, 1kHz, 60dBu?1%Signal-to-noise ratio (Mono, 60dBu) ?60 dBFreq

26、uency response(50Hz -15kHz)3dBStereo separation (1kHz; 60dBu)?35 dBUsable sensitivity (at S/N=20dB)?60 dB?THD (74dBu input , 30% mod )?3%1 signal Selectivity(at usable sen.)?20 dBImage rejection(at usable sen.)?28 dBI.F. rejection (at usable sen.)?40 dBS/N ratio(30% mod, 80dBu input)?40 dBPhysical S

27、pecificationsWidth Height Depth435x133x350mmNet Weight8.7kgShipping Weight10.3kgPower Consumption110W(50/60 Hz, at 110 or120VAC for AH, 230 or240VAC for C)Tuner AM Section(30% mod)- 7 -PCB-10 HEADPHONE BOARDPCB-2 POWER BOARDUL2468 AWG#26, WHITE, 150mmPCB-6 AC OUTPUT BOARDCZ45TRANSFORMERUL3266 AWG#18

28、190mmUL1007 AWG#22150mm270mmUL1672 AWG#22CZ703CZ702PCB-4 VFD BOARDPCB-7 OUT MODULE BOARDCZ703(Insert)CB62CZ701PCB-5 POT BOARD101UL2468 AWG#26WHITE, 130mmCB31PCB-3 KEY BOARDFPC 1.25-19P-710mm189WHITECB33CZ34(Insert)UL2468 AWG#26WHITE, 400mmPCB-8 IN MODULE BOARDCB61UL1672 AWG#18UL1672 AWG#22, 150mmCB4

29、9CB47CB45RED, 100mmPCB-9 MUTE BOARDCB34CB34CB32(Insert)(Insert)WIRING DIAGRAMCB59PCB-1 MAIN BOARDFPC 1.25-17P-180mmTUNER MODULE (KST-MB114MA0/1-23)CZ35WHITE, 500mmUL2468 AWG#26CON 01CZ36 CZ37WHITEWB01HS-001(C) UL1672 AWG#18CB58CB54CB52CB51CB55CB53RED, 130mmWB05HS-001(AH)CB56CB57AC POWER PLUGPOWER SW

30、ITCHTUNER RFROM TUNER MODULEINPUT SELECTIONCIRCUIT (BY RELAY)DISC LDISC RCD RVIDEO RAUX RTAPE RTAPE LAUX LVIDEO LCD LIC 33CD4094IC31NJU7313ALCPUCPUZONE 2 LZONE 2 RPREAPM MODULEAMP CIRCUITIN?PREAMP MODULEAMP CIRCUITOUT?BASSRT31RT32RT34TREBLEBALANCESW31TONE DEFEATRT33VOLUME MUTE MUTEMUTEQ310Q31Q32SUB

31、OUTCONTROL SUB OUT PRE-OUT LPRE-OUT RMAIN IN RMAIN IN LSOFT CLIPPINGCONTROL CIRCUITS41POWER AMP CIRCUIT LCIRCUIT RPOWER AMPIC 33CD4094PROTECTION CIRCUIT(IC44,UPC1237HA)SPK BSPK A457Q416Q417C1815C1815SPKA RSPKB LSPKA L SPKB R RL12/1JQX-115F /0242HS4AFRL12/2JQX-115F/0242HS4AFCPUISC CIRCUIT(IC43,TL082D

32、)TRIGI-VMIRROR SOURCESCRCIRCUIT234578212224252627(13,15,16)(1,2,3)(4,5,6,7,13,14)1112VOL-VOL+VOLUME CONTROL CIRCUIT (REMOTE)MUTECIRUITSTANDBY (CPU)JK41AMBER LEDCONTROL CIRCUITR467POSISTOR(80 DEGREE C)R439POSISTOR(90 DEGREE C)BLOCK DIAGRAMHEADPHONEFROM TUNER MODULETUNER RTUNER LCIRCUITCONTROLCURRENTC

33、IRCUITCONTROL CONTROL- 9 -231IC702IS1U60L+5V+5V+5VDATACLKSTDOUTDINCLKSTBIR OUTIR INPSEN29ALE/P30TXD11RXD10P2728P2627P2526P2425P2324P2223P2122P2021P0039P0138P0237P0336P0435P0534P0633P0732WR16RD17RESET9X218X119EA/VP31T014T115INT012P101P112P123P134P145P156P167P178INT113VCC40GND20IC704AT89C55WDRDS CLK13

34、2IC708TCM810MEND56IC70511.0592MHzIR OUTCIRCUITIR INCIRCUITIC31NJU7313ALSTDATACLKIC703UPD16311+5V-30VCLK9568STBDINDOUTENCODERCONTROLCIRCUIT10k2k470Q712+5VSandby control line24C6418V Power SupplyCircuitSTRDCLKIC7074094STRDCLKIC324094STRDCLKIC334094123123123DATACLKST2STST2STSTCLKCLKCLKDATADATA10K10K10K

35、10K10K10K10K10K+5VRDS DATAPLL CEPLL D0PLL D1PLL CLK1TUNERSTEREO123456789KST-MB114MA0/1TUNER MODULERDS CLKRDS DATAPLL CEPLL D0PLL D1PLL CLK1TUNERSTEREO22pF4.7pFMICROPROCESSOR CONNECTION DIAGRAMVddVddVee143334+5VFLASHPower SupllyDisplay circuitDATA912345678910111213141516171819202122232425262728uPC123

36、7HAMAIN BOARD: IC44Overload DetectorOutput Offset DetectorSwitch for latch/automatic -resetFlip-FlopVCC ONMUTEAC-OFF detectorRelay driver12345786GNDVCCAT24C64AKEY BOARD: IC705PIN CONFIGURATION12345678VCCWPSCLSDAGNDA0A1A2PIN NAMEA0-A2SDASCLWPADDRESS INPUTSFUNCTIONSERIALDATASERIAL CLOCK INPUTWRITE PRO

37、TECTWPVccGNDSCLSDAA0A1A2STARTSTOPLOGICLOADSERIAL CONTROL LOGICENH.V. PUMP/TIMINGDATA RECOVERYX DECEEPROMSERIAL MUX Dout/ACKLOGICDoutDinY DECDATA WORDADRR/COUNTERINCLOADCOMPR/WDEVICEADRRESSCOMPARATORICS BLOCK DIAGRAM- 11 -12345678910111213141516171819202122232425262728293031323334353637383940VccP0.0(

38、AD0)P0.1(AD1)P0.2(AD2)P0.3(AD3)P0.4(AD4)P0.5(AD5)P0.6(AD6)P0.7(AD7)P2.0(A8)P2.1(A9)P2.2(A10)P2.3(A11)P2.4(A12)P2.5(A13)P2.6(A14)P2.7(A15)PSENALE/PROGEA/VPP(T2)P1.0(T2EX)P1.1P1.2P1.3P1.4P1.5P1.6P1.7RST(RXD)P3.0(TXD)P3.1(INT0)P3.2(INT1)P3.3(T1)P3.5(T0)P3.4(WR)P3.6(RD)P3.7XTAL1XTAL2GNDAT89C55WDKEY BOAR

39、D : IC704PIN CONFIGURATIONOSCWATCH DOGPORT 1LATCHLATCHLATCHLATCHPORT 0PORT 2PORT 0 DRIVERSPORT 1 DRIVERSPORT 2 DRIVERSPORT 3 DRIVERSQUICK FLASHRAMRAM ADDR.REGISTERREGISTERBACCSTACKPIONTERPROGRAMADDRESSREGISTERBUFFERPCINCREMENTERPROGRAMCOUNTERDUAL DPTRINTERRUPT,SERIAL PORTAND TIMER BLOCKSTMP2TMP1ALUP

40、SWTIMING AND CONTROLINSTRUCTIONREGISTERP1.0 - P1.7P3.0 - P3.7P2.0 - P2.7P1.0 - P1.7- 12 -CD4094MAIN BOARD:IC32&IC332CLCLDQ1CLCLDQ2TRTRTRTR31* VDDVSS* ALLINPUTSPROTECTED BYCMOS PROTECTIONNETWORKCLCL8CLCLnpDQQ10CLCLnpQSSERIALOUT11Q8TRTRLATCH83STATE810QSSERIALOUTSTAGES3 - 74567121314LATCH23 -STATE2CLOC

41、K*STROBE*CLCLTRTROUTPUT ENABLE*15TRTRLATCH1pnnVDDVSSQ1Q2Q3Q4Q5Q6Q73 - STSTE112345678910111213141516STROBEDATACLKQ1Q2Q3Q4Q5Q6Q7Q8QSQSVSSVDDOUTPUT ENABLEPIN CONFIGURATIONTL082CP/DMAIN BOARD: IC3, IC4, IC34, IC43-+ +-AB12345678V+OUTPUT BINVERTING INPUT BNON-INVERTING INPUT BV-NON-INVERTING INPUT AINVER

42、TING INPUT AOUTPUT AKEY BOARD: IC707NJU7313ALMAIN BOARD: IC3112345678910111213141516171819202122232425262728L1L2L3L4L5L6L7L8R1R2R3R4R5R6R7R8VeeL-COM1L-COM2L-COM3R-COM1R-COM2R-COM3DATACLKVssSTPIN CONFIGURATIONLevel ShifterLatch CircuitLatch CircuitLevel ShifterControl CircuitR1R2R3R4R5R6R7R8L1L2L3L4L

43、5L6L7L8L-COM 1L-COM 2L-COM 3R-COM 1R-COM 2R-COM 3DATACLKVssVeeVddST- 14 -RVddDinDoutCLKSTBOSCSerial I/FCommand decoderDisplay memory20bit x 16 wordDimming circuit20-bit output latchTiming generatorkey scankey scan memory (4x20)5-bit latch4-bit latch16-bit shift registerData selectorGrid driverSegmen

44、t/grid driverSegment driverLED 1LED 5SW1SW4TO4Key1Key4TO42012816888Seg1Seg12Seg13/grid16Seg20/grid9 Grid 8 Grid 1Vdd(+5V)Vss(0V)Vee(-30V)uPD16311MAIN BOARD :IC703PIN CONFIGURATION(Top View)12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152Seg1/KS1Seg2/KS2

45、Seg3/KS3Seg4/KS4Seg5/KS5Seg6/KS6Seg7/KS7Seg8/KS8Seg9/KS9Seg10/KS10Seg11KS11Seg12KS12VddSW1SW2SW3SW4DoutDinICCLKSTBKEY1KEY2KEY3KEY4Grid6Grid7Grid8Seg20/Grid9Seg19/Grid10VeeVddSeg18/Grid11Seg17/Grid12Seg16/Grid13Seg15/Grid14Seg14/Grid15Seg13/Grid16OSCVssLED1LED2LED3LED4LED5VddGrid1Grid2Grid3Grid4Grid5

46、- 15 -ALIGNMENT PROCEDURESI. INITIALA. LOWEST VOLUME ADJUSTMENT3. Connect a oscilloscope to L channel binding posts.1. Tune the volume pot to lowest state.2. Input a high voltage signal such as 5V from CD input.4. Observing the oscilloscope,adjust VR301,make the output of speakers become to the 5. A

47、djusting VR302,make R channel output become to the lowest level by same way. B. IDLING CURRENT1. Connect a DC voltmeter toTP1 and TP2 ,adjust VR22 for 4-5mV reading on voltmeter.2. Connect a DC voltmeter toTP3 and TP4 ,adjust VR12 for 4-5mV reading on voltmeter.3. Level power on for a minimum of 5 m

48、inutesII. FINAL ADJUSTMENTRepeat procedure A and B for lowest volume level and idling current alignment respectively.TP1TP2TP3TP4VR22VR12VR301VR302MAIN BOARDlowest level.- 16 -C61220pR61220R631M Q612SK170R671KR69430 2%Q63A970Q67D667C6322pR6111KQ64B647R61310KD611N4148D621N4148R61533C650.1u 20%C660.1u

49、 20%C69100pR61710R61910C62220pR62220R641M Q622SK170R681KR610430Q65A970Q68D667C6422pR6121KQ66B647R61410KD631N4148D641N4148R61633C670.1uC680.1uC610100pR61810R62010123456789CB61CON9R621120C61115pFGND+18V-18VLOUTROUTRIN-RIN+LIN+LIN-PREAMP OUT MODULE CIRCUIT FOR Vm1.6123456789CB31CON9MOTO POT FOR Vm1.637

50、28RT33APOTALPS3645RT33BPOTALPS910RT33CPOTALPSRCA31ADISCRCA31CCDRCA32AAUXRCA32CVIDEOR31470R33470R35470C31100pC33100pC35100pR37470C37100p465RL31B465RL32B465RL33B465RL34BR34922KR35122KR35322KR35522KL-CH INPUTSC720BEE INPUT SELECT CIRCUIT R39470C39100p465RL35BR35722KRCA31BDISCRCA31DCDRCA32BAUXRCA32DVIDE