Luxman-K12-tape-sm 维修电路原理图.pdf

《Luxman-K12-tape-sm 维修电路原理图.pdf》由会员分享，可在线阅读，更多相关《Luxman-K12-tape-sm 维修电路原理图.pdf（43页珍藏版）》请在收音机爱好者资料库上搜索。

1、RadioFans.CN 收音机爱 好者资料库/) A C ,-(-(Jptri-,i0tc )(/.ucnSER/|cEMANUALLUXMAN srEREo CASSETTE DEc K-12RadioFans.CN 收音机爱 好者资料库IK-l2 Electronic Section Alignment procedurelo.ITEISTAPEREQUI REDSEIECTOR POSITIONEQ SW I BIAS SWINPUI SIGIALALI GIMENT PROCEruRELIMITED SPECREMRKSP/B Output LevelMTT- 150TIORMAIN

2、0FX/IALPlayback EAC MTT-150(Dolby 1eve1; 400H2 200nwb/tn)and adj ust trjrnEr potentiorneter to obtain outputlevel of 580nV(-2.sdBn).Ldr P/B Gah trR: T.-107aRcl P/B Gain lR: VR-107b-2.sdBn-0. SdBnDolby offOutput VR:MAX.-t a-L ,r ia,.r, f_IFY ni finMTT- 150cfizEXNOFMALNORMALMter the step (1), check th

3、e P/B output level at theCIOZ node,Also check that at EXr node.-2.sdBnio. sasIf ratedIevel cantbe obtained,arnp circuitnay be sr.E-Dolby OutputLevel CheckMTI- 150NORT,IAI NORMALSet the Dolby Sw to ON and adjust tritrner pot forDolby level adjust to obtain output level of 580nV(-2.Sdhn) at LINE otn j

4、ack.Lch Dolbv Gain R: Rl03aRcI Dolbv Gain R: VR103bDolby on.Dolby OutputLevel Check withMPX filter 0lMTT- 150NOM,ALNOFMALSet the Dolby Sw to lrPX filter position and cleckthe Dolby output level at LINE OJI jack.Dolby SwrPx filte/position. Ifout of spec,anp circuitnay be sus-Bar-Graph lvelAdj ustnent

5、MTT- 150NORMALNORMALAdj ust trimer pot for bar-graph leve1 adj ust toobtain 0w indication at 580rnv output level of LINEoln.Ldr Bar-GraDh Level Adi ust R: RI04aRah Bar-Graph Level Adl ust R: RI04bodB I 0. sd3(odB levelshould lightup. )Playback HeadAzinuth AligunentMTT- 216NOFI|ALNORNALPlayback MIf-2

6、16 3180uS +120uS) to reproduce theazimrth aligrunent signals (6.3kH2, 10kHz), andadj ust the aziruti adjust screw to obtain the natim,unplayback output level,Also dreck, nonitodng l oscilloscope, if there is nophase-shifting between L and R charmels,Playback EQAdj ustrnentMTT- 216IIORMALNORI(ALPlalt

7、ack MTT-216 to ciec-l( that the first stardard siq-na1(3t5Hzl should be at -5.Sdln I 0.sdBm. Thenreprcdrce ioldlz signal, and a+j ust P/B EQ trirmer toobtain outDut level of -25.5 -0.5d&n.Lch P/B EQ trirrEr pot : VR-108aRch P/B EQ trirner pot : R:108b10Klz output ,teve-L: -15.5 -0. sdBmDclby offNO.r

8、lIltsTAPEMQUIREDSELECTOR POSITIOI.IEQ Sw I BrAS sllINPIT SIG.ALALIGOIENI PROCEUJRELIIITEDREMARKS8.P/B FrequencyResponse Adj ust.(nonnal )tIT- 216NORMALNORIIIALno sigralPlaltack MTT-216 standard frcquency response signal(315H2), and nake note of the output 1eve1. Thenplayback the frequency adjr.Etnen

9、t signal frcrn 31.5H2to inkHz. At this time, the playbagl output levetat eaci frequency should be within :2d&n when thestandard output level is regarded as zero (0).Should bewithin:2d&n,referencing3l5Hz signalas 0.Dolby off9.P/ iJ frequencyResponse Adj ust.(CrO2, Ex)MTT.316CrOzEXNORiiALSet EQ Select

10、or to CrO2 (or EXJ position. Playback standard frequency signal 315H2 of MTT-316(5180uS+70uS), and rnake note of the output level.Then playback frequency aligunent signat from 31.sFlzto l4ktlz. At this tine, the playba$k output levelat each frequency should be withir :2d&n rhen thestandard output le

11、vel is regarded as zero (0).Should bewithin:2dBn,referencilg315H2 signalas 0 zero).Dolby off10.P/B Signal- to-Noise Adjust.NORMALNORMA-LPut the deck node without loading cassettehub, and check noi.se 1eve1 at LINE oUT Jacks.Noise lve1 - no nore than -50dln(R4s)Likewise, check that at the respective

12、mode: CrOZ,E)c, Do1by ol1, I.|PX. FILTERShould be nolDre than- 50d&r at eachnode11.Frequency Adj r.lst.of BIAS OSC.cfzCrOZComect counter to the current output tenrinals oferasing head lterninal No. 19 (+), No. 18 (-).set the BI.as sw. to cro2 node. Ilm the BLq.s osccoi.1 to obtajn losdlz oscillation

13、 frequency.BIA.5 6C Coil - L-201Al-so check if oscillation frgquency at each INORMALand Exr Dosi.tion is 10skHz -skHz.Bias oSCfrequency:105ktlz at CrO?105ldz:sKtz-At NORMAL & EXRECnode12.Bias Trap Adj ust.at REC EQ AMP.EXEXCormect Wl4vl before trap coil at mC EQ AllP for bothL and R ciarmels, ard ad

14、just trap coil to obtainninim.un reading of vTlU.Trap Coil - L-ch L-105a- R-ch L- 103bAt this tine, the VTW indlcaticn should be no norethan +20dBrn.VTVM readi-ngshould be nomore than+ 20dBn,13.Bias Cunent Adj.NOFXIAL NORMAICrOzCormect VTW across the 10-ohn resistor of the recordhead.L-ch Tenri-nal

15、No. 42 - (+)Terninal No. G.lD - (-)R-ch Teminal No. 48 - (+)Terninal No. G.lD - - (-)(l) set the Blas sw to lioRMAI, and pre-set tlec1rrrent - flow through the 10-ohn resistor to 300!A.Trirmer Pot for NoRMAL BIAS ADJ. - Lch 4202aRdr I/T202bNOFMAL 500!A(=3nV, at 10ohns),J0.TEI6TAPEREQUI RENSELECIOR P

16、OSITIO.IEQ Sw I Br.s SW1NPUT SIGALALIG.IMENT PROGUJRELIMIIED SPECREIIARKS(2) Set the BIAS sw to CrO2, and preset the BIyScurrcnt to 400!4.rrinnner Pot for cro2 Brrls *j - ks w31;(5) Set the BIAS sw to EX, and preset the BIAScurrent to 650uA.Trirmer Pot for EX BIAS Adj. - Lch T203aRdr R201bCrO2 400uA

17、(=4nV, at 10ohns)EX 650u4(= 6.5mV, at10 ohrns)4.Peaking Adjust atMC. EQ. AN,IPNORIALcfzEXNOFMAL18kHzl0onv( - 18dBn)2014122IkHzTo keep out the action of B1AS OSC, insed a tj.p ofpaper in the leaf switch connected in series withthe power slpply to the oscillator. (The leaf Sw isplaced near the nain so

18、lenoid.) Then put the deckinto the RECnode.(1) Set the Equalizer Sw to the iNoRNAI position,and apply l8kllz 100rnv signal to LINE IIPUT.Adjust the peaking coil for NoRMAL to obtain themaxirRm output at the 10-ohn resistor of the R/Pneao.Peakjng Coil for NoRI4AL - Lch L105aRch L106b(2) Set the Equal

19、izer Sw to the CrO2 position andapply 20kHz 100rnv signal to LINE INPUT. Adjr.rstthe peaking coil for CrOT to obtain the naxiflunreadins on the VTVNI,Peaking Coil for CrO2- Lch Ll04aRch L104b(5) Set the Equalizer Sw to the Etr position andapply 2tkHz 10OnV signal to LINE INPUT, Adj ustthe peakirg co

20、il for EX to obtain the naxijntnnreadins on the T4,1.Peaklng Coil for EX- Lch 1106aRch L106bEadr peaki-ng leve1 at the respective rcde, NORALCrO2 and EX should be apprcxinately 20dBn at18kJ1z, 20HIz, zlldlz, conpared with that of lkHz(4) Do not forget to renrve a piece of paper put onthe leaf switdr

21、.Adj ust peakingfor NoRI.1ALnode by use ofl8kHz signalAdj ust peakingfor CIOZ nodeby use of20kHz signalAdjust peakingfor EX node byuse of 211clzs ignalOutput shouldbe measuredacross the10 - ohnreS1stor.5.REC GainAdj ustnent(NORIAL)AC-22rNOFIALNOFMAL400H2, 100mVl3dB(-i8dBn:icB)Output 1eve1 atLINE OUT

22、, noni-toring source,should be 580rnvAdj ust the REC Gain trinner pot to obtain LINE oUToutput level of 580nv(-2.5dh) when the AC-ZZI tape400H2 si$al is recorded and played-back.NOR iAI REC Gain Adj Lrstnent Lch Rl10aRcn !R110b- 2. s :0.5 dBnInput Levelat LINE INshould.be-18dB : 3dB.No.ITE6TAPESEI-E

23、CTOR PGITIONEQ SW I BIAS SW_lNpur srciAlAIINMENT pEnrFnrrDEREQUI REDLIMIIED SPECREMRKS16.RECAdjustrEntt croz)AC- 511CrO2cfz400H2,100mV I3dB-(-18den 1 jdB)Lrtput level atLINE oUT, moni -toring source.shoul d hc qRnhl/ffiifrl infhfr3liff;#to obtain LINE ouT400irz signar i,il; #;r$:l_;l&1.-ttt .*CrO2 R

24、EC Gain ldj ustrnent Lci lRlogaRdr !Rl09b-T15i.n. sare ali grunent pro.aur.Er.it.IT ,GpEx mc Gain Adjusrnent kS H+lf,-2. s t o. sdgtInput Levelat LINE INShould hc-rsdB:aB17.REC Gain Adj ust.tEx)rnet a1particle(AC 70r)EXEXSa.ne as aboye.18.Bar cruph Dis -play Oreck atE)CnodeEXEX:.&ii-;r, iaiJdtiSt i3

25、il:lS 3h:f*il *$.1*i :?:,iT6i*:;iru f #iilf;:il,-4dB indicationof tle BarGraph at theEXpositionof EQ sw 6 BIAS5W.Input Levelat LINE IN19.REC FrequencyResponse Adj ust.(NORtitAL)AC-221NOm4AlNORl,lAL30-16kHz -20lBagainst stan-dard i_nputleve1p$-#i q*#irTix :$ff ,r*rd$.i . -0 I 3dB at eachfreqtrencyInp

26、ut Levelat LINE IN- Sgann l:.lBz0REC FrequencyResponse Adjust.I cro2 )AC-511CtOZCtfZ30-18kHz -ZodBagarnst stan-dard input1eve1. _,. wuLpuL rs regarced as odB.f,lr*#il f;i*r-ti# i$sit -sr:i,0 I 3dB at eacifrequencyInput lvelat LINE IN:- 5 8dBn:3dB2IREC FrequencyResponse Adj ,(Ex)metalpart tcle(AC- 70

27、1)EXEX30-20lGlz -20clBagainst stan-dard , inputlevel:ff :J:,:Tilj:fftllJi:if,$ff 1;., ffi, ji,)o I 3ds at eachfrequenryInput Leyelat LINE IN:- 38dBm:3dBI . I r(cL rrequencyI I Response Adj nst.| | rn specral caseec-zzr I ruonvru.AC- 511 | CIOTmetal I FY-particle Irape I(AC- 701) INOFMALCrOzEX30 - l6

28、ldtz30 - 18kHz30 - 20l4lz-20d8 againststarq2rd inputIEVElii,fi; g:.iiil:lfl ffiffr: does not neet therzor, i J! -ir, iiilluto JB.ff ,B:* steps ( re ) -,) Tgtl thu Freq. resposne shorvs drop both at 4-81+tztnrdrange) and over lSkHz(treble). S iin. i- Lower the bras current. fTum the lRcor.trl_,. . te

29、r-cloc*wise di rection. )wnen they are both increased, See fig. 2U)zIffi-r lq. 19l ri. a91- -r-r9,1 . r l- rlLrcitse .ne Drts current. (Tum the VRclockwise. )b) lrrhen the frequency response drops only at treblerange (over l0lGtz). Sie fig. 3- :nr,tl peakrng froint downward by tuming the,_ peat(rng

30、coil clockwise.il:rrli: response increases only in treble range.zI-T=ft0kI0k2kFI#;i;!trilt.ffintrupward bvetumins the)i- |II0tN0.ITEMSTAPEREQUI REDSEI-ECTOTEQ $/ |POSITIONBIAS SWINPUI SIG.IAIALI G4ENT PROGnJRELIIITED SPECREMARKc) Never forget to check the output level of 400H2standard recordi-ng/pla

31、yback signal I,JtIen the trir-ner pot for BIAS adj ustnent is tumed for aligDnentof frequency response.d) Extrene tum of these pealing coil and BI/s adj ust8.s nay ca,rse deterioration of distortion dlarc-teristic or d)nanic range of record/playbackoutputs. Therefore, when these positions are founde

32、xtrenE, electronic circuit nay be suspected.(Check the operation of the circ1lit,)23.Adj ustment ofLINE-OUr BiasTrapEXCroZConnect mlM to LINE OJT and set the node to mCoRDand check output of BIAS leakage.Tjm the trap coil so that the output of BI.aS leakagenay me to the ninim.m.Oreck the output of B

33、IAS leakage j.s less than - 40dBnfor all CrO2, EX modes. In case itis norc than -25d8, re-adjust it.EX node - Lch L-101aRch L-101brrCrOZr node - Lch L-I07aRdr L- 107bBelow - 4odBrnafter znd lotrlRXCr nodeIblby offAligunent ofDolby l4PX filter(rgkHz)NORMALNOFIALlgldlz standardinput level.Apply lgkHz

34、signal to LINE IN. Comect VTt4vl to LINEoUT te:llf.nal and adjust the coil for lgkHz filter toobtain the nfnfur.un reading on the Wi. Thj.s align-nent should be done in the REC mode.The coil for Lgldlz filter: Lch L-102a RED COmRch L-102b mD CoRE19kHz outputat LINE oUTshould be theninimrn (nonore th

35、an-32.5d8n. )Input: Line1nDolby MPXFilter 0l1.25.Aligrunent ofDolby MPX filter(approx. 105kHz)croz10 Sktlzstandard inputlevelComect VTVM to REC.oUI telminal. Set the deck in theCrOr Dosition ard REC PAIEE node. Tum the coilof Bias Tr4 to obtain the njnijlm reading on theVTVM.Bias Adjustnent coil- k$

36、 i_133f, Bstr sffiThis step No.25 nay be onitted since this alignnent isdone as low-pass filter at the coil slpplier. When itis qnj.tted, however, dreck that the bias leakage atLINE OUI is less than -45dBn at each NOR!,iAL, CrOzor ,E)C node wilh tl)lbv CFI.Bias Leakageoutput at LINEOUT should bernin

37、irun.(no nore than-45dBm)Input: LineInDolby MPXFilter 0ll26.Dolby FrequencyResponse GreckAC-22rNORMALNORAL30 -lsldlz-20dB againststsrdard input1eve1Apply 30-15ldlz signal to LINE IN and dreck the outputlevel at LINE 0JT.Thg record/playback output of the signal should be0 : 5dh, riren 400H2 standard

38、input signal 1eve1 isregarded as 0dB.odB 1 sd3Line InDorby chlN0.ITEI4STAPEREQUI REDSELECIOR POSITIONEQ SW I BIAS SWINPTN SIGIAI,AIIGIMENT PROCETIJRLLIitrTED SPECREMRKS27Record/ Playbackoutput lve1Greck at Drlby-oN ard -oFFAC-22rNORiTALNORIAL400H2 standardinput signallevel (odB 1eve1on tlte BarGraph

39、)Apply 400H2 standard input signal to LINE IN andrecord/p1ay-back lt. Theoutput 1evel at LINE oUTterninal should be 580nV .l 1dB both for Dolb/ 0Nand oFF5 Solv:1dBDolbyDolbyONOFFAligrurEnt of SAat record/play-backAC-22rAC- 511netalpar-tic1e(AC- 7011NORIALCtOZEXNOFMALcfl2EXno signaltlnload the LINE I

40、N tendnals, and nake rccord/playbackof the tape. The noise 1eve1 at this the should beless than -47dBn(RISI .Check the noise level at CIOZ and EX position in thesane nalmer.Both at the Dolby 0N and Dolby MPX FilteI 0,1, thenoise level should be less than -49dBn.Reco rd,/P 1ay -back noise1eve1 should

41、be less than-47dBn(RIS).Re co rdl P 1ay -back noise1eve1 shouldbe less thar-49dBn(RI4S).?t)Check of ErasureAC-221AC- 511netalpadicle(AC- 701)NORI,IALCtOZEXNORIALCrOZEXlkHz +10dBagainst stan-dard input leve1Apply lkHz - SdBrn signal to LINE IN ternfnal, aldrecord it. Next, rnake note of the output le

42、vel.Ihen, discorurect the input signal and erase therecorded signal. Check the output 1eve1 at the erasedportion thrcugh lkHz band-pass filter, and rnake noteof the di.fference cqpared with that before erasi-ng.Output Level before erasing - al (den)Output lve1 after erasirtg - a2 (den)Erasing Capabi

43、lity - A = al-az(dBrn)Take the same procedure iI the Cro2 and EX nndes,ErasingCapability Ashould bebetter thar70dBnUselkHzbard-pas sfilter30.0rannelSparation GreckAC-227AC- 511metalpartidetape(c- 701)NORTA.LCrOZEXNORXIALlkHzstandardinput 1eve1(0dB 1evel atthe Bar GraphRecord lkHz about - l8dBrn sign

44、al thrcugh Lch LINE IN,and play-back it, Then neasure the rccod./playbac-koutput 1eve1 of Rch via tkHz band-pass filter. Atthe sane tifle neasure the record/playback output ofLch.Record/Playback Output Level (Lch) - af (dBm)Record/Playback Output Level (Rdr).- az (den)Crcsstalk frorn Lch io Rch: A =

45、 a1 - a2 ldB)Likewi.se apply signal to Rch to neasurc the crosstalkfron RclI to Lc.h.Take the sane procedure at eadl ncde with Dolby 0,I.better than3 sdBUse lkllzband-passfilter.Dolby OFFDolby ON1tCrosstalk0reckMTT- 12IPlay-back test tape MTI-121, and neasure the leakageas per the following mode,Ldr

46、 to Rdr (lst track to 2nd track)Rcl to Lch (2nd track to lst track)better than50dBUseIWlzband-passfilter.-:ratrl!|lqtFr -r- K-I2 IGOIANICAL PAXT ALICNTOT PFOCEIIJREIlo.ITE!6TAPEmqrrnEDSELECTOR rcITICNEQ silr I BIAS srrINPUT SIGIALALIGNIETI PROGTTRELnIlED SPEC RF.ARKSI234Check ofEject Sw.Oteck ofBias

47、 osc. Sw.Oreck ofTape SpeedCheck of WorMtr-11lDMm-11lDr)Cmfirn tiat tlre &ck does not stop and that thecassette lid bes not open even hfin the EjectButtcr is prssed drring crperation.Cmfinn that in the noabs of FF snd,FElf witha toudr to the Eject Button tlle deck stopsoperation prior to openiag of

48、the cassette lid.2)oonfim that the bias osc. switdr is turned on uiEnthe head drassis fincticns and tlat it is not tumedoff at tlF SIOP node,Cormect a digital cotmter to the LINE ol.rTPUT, andwith Mm-lllD tspe the digital cornter shows2,985 - 3,0l5Hz.The wc tee IOT-lllD is loaded, and a wow neter is

49、comected to the IJNE Cf,rT tenninal. wot is nEasuredboth at mG md ltr0|S.Tape speed:2 ,985- 3,015H2Fl*6: belod0.ltWRlr6: below0.04*Kev Switch PCBSYMBOL NO.PART NITBERDESCRIPTIONNOTEQUANTITYPER UNITPCM-004s-0018A-0021YM-0199Key Switch PCBKey Tact SritchLampBush 3008PCMo045V0. 075AI133tofT;0t;, 1._j+Y

50、GYREMPLACERDU T.g E TYPE.ac ut6v rlimATPCta -o20 lrL-?t-gour P/B i,rnNca7Fuse PCBREPLACE WITH SAIiE tYP FUSE ONLY.SYMBOL NO.PART NIJUBERDESCRIPTIONNOTEQUANTITYPER UNITQ50r, 502D501,r, 504R503R502R501T-0025T-0010R-0001Fuse PCBTransistorDiodeCarbon ResistorPCM-02025C2320Frs-247 31/4W 3. 9KQ 10Kn 4 7KA