YAMAHA k-1020-sm 维修电路原理图.PDF

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1、$ ,t STEREO CASSETTE DECK K-l 0n I FRONT PANEL ; a IJITPORTANT NOTICE This manual has becn providcd for the use of authorized Yamaha Retailers and their service personnel. It has been assumed that basic servicc proccdures inhcrant to the industry, and more specifically Yamaha Products, are alrcady k

2、nown and understood by the users, and have thereforc not been rcstatcd. WARNING: Failure to follow appropriate service and safety procedures whcn servicing this product may result in personal iniury, dcstruction of expcnsivc components and failure of the product to perform as specificd. For thesc re

3、asons, we advisc all Yamaha product owners that all servicc required should be performed by an authorizcd Yamaha Retailer or the dppointed rer vice reprerentativc. IMPORTANT: The prescntation or salc of this manual to any individual or firm does not constitute authorization, ccrtification, recogniti

4、on of any applicable technical capabilitites, or establish a principle agent relationship of any form. Thc data provided is belicved to be accurate and applicable to the unit/s indicatcd on the covcr. The rcscarch, engineering, and scrvice departments of Yamaha are continually striving to improve Ya

5、maha products. Modifications are, therefore, inevitable and changes in specification are subject to change without notice or obliSation to retrofit. Should any discrepancy appcar to exist, please contact the distributors Servicc Division. Static dischargcs can destroy experrsive components. Discharg

6、e any static electricity your body may have accumulated by grounding yourself to the ground buss in the unit (heavy gauge black wires connect to this buss). Turn the unit OFF during disassembly and parts replacement. Recheck all work before you apply power to th unit. I H YAMAIIA .,- !.!.,-! !,ts,+

7、-t - L-rL) AL-t : u Lt,t_t Lt l E :rr:rr_- t-EE- f-ffir-il ILIL- -(DS,0 (D il I CONTENTS TOSERVICEPERSONEL .1 REARPANELS. .1 BLOCKDIAGRAM .2 SPEC|F|CAT|ONS. .3 INTERNALVIEW. .3 DISASSEMBLYPROCEDURES . . 4-6 MECHANICALADJUSTMENTS. 7 -9 ELECTRICALADJUSTMENTS . .9-11 LSI DATA TABLES 12 TIMINGCHART .13

8、PRINTED CIRCUIT BOARD (Pattern Side) . . 14 - 17 wtRtNG . . . . 18 fcBLocK .19-21 SCHEMATICDIAGRAM .22,23 PARTSLTST. .24-36 SINCEI87 YAMAHA NIPPON GAKKI CO., LTD. HAMAMATSU, JAPAN 2.5k 533 El Printed in Japan. 85 . I _ .1 2. K-ro2() I TO SERVICE PER,SONNET Cntical Components I nformation. Components

9、 having special characteristics are marked and must be replaced with parts having specif ications equal to those originally installed. Leakage Current Measurement (For l20V Model Onlv) When service has been completed, it is imperarive ihat yo, verify that all exposed conductive surfaces are properly

10、 insulated from supply circuits. Meter impedance should be equivalent to 1 5O0 ohm shunreo by 0.1 5r F Leakage current must not exceed 0.5mA. Be sure to test for leakagewith the AC plug in tjoth polaIrres. I REAR PANELS U.S.A. xd. ;u EH. ./i -s-s :t EtrL l/,a ; tru, ; o G Y z o 2 t z = U 3 AEo a s I

11、 G F c F I tu c az zo oo = ,t| n lo P f dl of ee?l , pp;l i =*l F s3- . 6El ,I ,n :u d -ri5q u! o o U F AY yJ; F- 9e a* .H l V l !- U- o 8ts U all nqa - FZ ol r/ UI nF lf lzl J- 6JoJ u 6 ;r JI utz _t o ua = , | - o JO a-iN-fiJ tq ld isK r =l/, -J nl 5A 9+-. 35 | Xfi Y L Ef I *l -l *rl7 |nL -,1 ,Q. I

12、 E U J E F lr, = J d) O- lrJ I a K-|o20 T SPECIFICATIONS Type4-track. 2-channel stereo I nput Sonsitivity I mpedance Li ne 40 mV/30 k-ohms HeadR No more than 0.03% (W. RMS) Power Supplios U.S. Tfil t, BE - 312 1 E: G model- RE: A, B models Fig.2 d. I : I i i I ; i i ! ARemove 4 screws ) in f ig. 5 a

13、nd pull out mechanism unit gradually to the rear. Replacement of capstan motor Remove the mechanism unit. Remove 4 screws in f lg. 6 and remove the back- plate. O WIRING OF MECHANISM UNIT the 3. a. b. Fig.5 r / I J A I I I i j i . Srtting flywhsl belt (viryed trom the rsr) Fig.6 Sensor Circuit Board

14、 Reel Motor - Lavel A F c. Remove 3 screws molor. ) in Fig. 7 and replace the capstan Fig.7 4. Replacement of reel motor a. Remove the mechanism unit. b. Remove 2 screws in Fig. 8 and remove the blind Plate. c. Remove the reel base as shown in Fig. 8. Note that coil springs of the supply reel and ta

15、keup reel are different. Supply side: Silver Take-up side: Green d. Remove the back plate (Refer to Fig. 6.) e. Remove the washer in f ig. 8 and remove the flywheel (take-up side). K-ro20 Remove 2 screws and nuts in Fig. 9 and remove the reel motor installation plate. Remove 2 screws ln fig.9 and re

16、place the reel motor. Reel Motor lnstallation Plate Fig.9 5. Replacement of assist motor a. Remove the top cover. b. Remove the blind plate. c. Remove 2 screws in f ig. 10 and remove the assist motor installation plate. d. Remove 2 screws in f ig. 10 and replacethe assist motor. Assist Motor lnstall

17、ation Plate Assist Motor Fis. l0 s. 6 Capstan Motor Push the reel base to the rear and remove the ring. Fig. I K-ro20 I MECHANICAL ADJUSTMENTS 1. Before adjustment o Since head magnetization, dust accumulations, etc. are likely to introduce error in the various character- istics, it is very importan

18、t that the heads are properly demagnetized and cleaned. 2. lnstruments required . Head Gauge (M-300) o Audio frequency oscillator . Oscilloscope . Mirror Cassette MC-109C a Torque meter o Wow/flutter meter o D.C.V.M. (DC Voltagemeter) . A.C.V.M. (AC Voltagemeter) /r 2-r1 . t Adlustmnt atm Tape Test

19、Point Instrument required Mode %H.l:iH:, lAdiustmenti natine I Remarks 1Check clear- ance between take-up side pinch roller and capstan shaft. PAUSE Fig. AMore than O.5 2Panch Roller Timing BFig I STOP lWith head base I jpushed up, j icheck timing at I which pinch I lrollers on I isuoolv side and I

20、itake-up side lcontact capstan Take-up side Pinc roller should start I rotating first. I l lli timing ot both lsides is samultane- ous or supply side precedes, adj.ust lment rs requrreo. I t- Height of re- cord/playback had and tape guide ig.o A.C.V.M. Oscilloscope t, ir- t*tt (MC-109C) -Trq*t* (Cas

21、sette type) Repeat adj ustment in steps 3 to 6 and apply screw lock parnt upon comp- letion of adjust- r9!. Adjust by using spacer as shown in Fig. H. f Ot.n t.t P torque, read the center of deflec- tron. Headgauge L (M 3oo) I I 1l Headgauge I lwithM300 (M-3OO) I lblock placed I lverticallY on re I

22、lcord/Playback I lhead, adjust so I lthat M 3OO I lgurg and block i oecomes Parallel I l(Fis. E) -n.asffi (M-300) i i PB Supply side Head gauge should oinch rotler I pass through smoothlV height adiust- lwathout i.ts block con- ing screw (Fig. Jtacting pinch roller c) lguide. (Fig. F) n.i. rtn aa- E

23、avback output of L justing screw and R is maximum (Fig. C) jand Phase difference I lshould be minimum I I (Phase difference less I lthan 60) r lTape should move in 1 lthe center of erase lhead smoothlY lCapstan (suppty side) I lshould move smoothlv. rvu,- Fr -T- -ffi?,c, REWtorque, i 35-559/cm take

24、up torque 1 i FF, REW torque and back tensi- I more than 7oglcm on torque. Back tension: I Back tenslorl: lAdjustleaf 5-1Og/cm spring (5 steps) iFie. t) I 4 R eco rdlpl a V back head tilt angle 5 SupplV side pinch roller h eight Fig.F 6 Azimuth1OkHz, -10d8 (MTT- 1 14) LINE OUT 7 Check Posr tion of e

25、rase head and tape movement. Check each 9 Check FF and BEW tak uP t ims AC-512 712,22a c-60 I I l Normal; Less than u5 I I seconds I I High speed: Less than I I I ssseconds Check speed lsmr f xed varr I3OOO +.:Hz whileplaying ar,leresrstorat J -rc jback 3kHz test the back of the I tape. lg_apstglt M

26、otor. I (Fiq. J) t0 Tape speed3kHz, -10dB (MTT- 111) LINE OUT Wow,/f lutter meter Frequen cy counter PB Wow/ F lutter 3ooo +., !uz I Less than O.O5% Check wow/flutter (WRMS) while confirming 3kHz frequency with wow/flutter meter counter. -1 l. I I I I lo?lJli3l ;,TlI clearaoce l6190r. K-ro2() Fig. B

27、 Fig. c t-rg. E Difference beMeen A .nd B Less than l/2 *Make sure to reconfirm after sdjustment Adjust by beoding head base contscting part of supply side pinch roller. Confirm clearance and t;ming atter acljustment. There should be a clear- ance between lhe pinch arm and head base on both supply a

28、nd t6ke- up srdes. Take-up Side Pinch Roller - a Tape Supply Side Pinch Roller Height Adjust Scrw Capstan Fig. A Fig. D Erg Head . Hesd F ix Screw r Tilt Angle Adjust Scrw - -A: Be sura to tighten the head fixing scrfl securely, Be sureio apply scrw lck painr to each adjusiing scrry after sdjustment

29、. ,/a (t) 7 Head Gauge M.300 e y il I .il|ti- It | .il|t I il t ililt l ll L- .t | r-_I_- r -_:-J I l_- Head Gauge M-300 Adjust so that the same clearance is obtained at the upper and lwor parts. E ;* Take-up side Pinch Floller Fig. F Fis. G K-ro2() Use spacer to adjust the h8sd heighl Fig. H Fig. I

30、 Capslsn Moto. Fig. J I ELECTRI CAL ADJUSTMENTS O PLAYBACK ADJUSTMENTS * Make sure to use a new tape of I EC standards for a test taDe. Alignment tape Normal TDK AC223 or YAMAHA NR 60 CrO2 TDK AC512 or YAMAHA CR 60 METAL TDK ACl12 or YAMAHA MR 60 o Proceed with the playback adjustments after having

31、finished the mechanical adjustments. (dbx circuit I I dbx circuit i I 1 board) 1-_1 I board) I . RECORDING ADJUSTMENT . Proceed with the recording adiustments after having finished the playback adjustments. t u He8d Hei0hr Orivcr / / (- F;f *r;,-.;-l-;- -j-,*l1;l*- Tffr# JW; 11 E.o- r J;iat-r- I D.c

32、r/M frtor l *roiril- o.rfoc - i iDc.offset lrP2B)-E i I I vR102(R) i i-t-lFryb.ki r - itztzc l Lrrveou-f-eivnr-trl uRlon-L) -i 36otls-v - I I | 1stsa, i (Acvort/da I I vR1o4(R) I t-g.o+tdBv) i I I toonwo/m/ I I rvteter) I l F_+ _+ _ _ f_t _ I I s i etayuacr rrequency Mrr.3s6u I r-rr.re oui I ; 6nt i

33、 t-f-T;*;,*; J i r.oonre conf irmation I 3t80 + 70ps1 i 1 1 lshoutd be wrthin specif i-response conTtrmatton (J tUU + /Ups, 1 i lshould be wtthin speciti- I ,.I,.r;,tuo|, I I i lcationinFieK a ldbx rc 1 Tpl -rp2 D.C.V.M. 1 Srop 1 vRTOt i 15 t 2mV D.C. I I (dbx circuit dbx circuit t-Aai-tfntT , -tTt

34、T.rj:l:jt- ,. . M.u,-nt Jnaitln,tl *;- *.*,- n.n=.;r lL;F;* faoa*. Appry a rkHz sine *;-u*.tLr-r l*aaE rn-*,-i -l Meter OUT signal from LINE lN so iVR5O4 R) I (red should I r 1(+4.5dBl I rLiNE l-Au;it that LINE OUT voltase rs I ltisft. I r ltno uott j li-,i fll$,., $J*,i,-iyJrlirtase is I lrisht i f

35、F;k L*f oscillator f,ppty r ri. rinu *u* fvnsor tr-r I ooe ,g-n, -iwrtn nllnsrEn -l Meter signal from LINE lN so 1VR502 (R) i(redl should FADER isdecreased L l l(OdB) 1 that LINE OUT voltage i tliStrt. and R segments i is 360mV (-gdBV). L around OdB should I 1 fade out almost simul- * Use 360mV (-9d

36、BV) for 0dB as the standard level of this unit. . )A 9 8ek Teosion (5 iteps) at Playback mode l(OdB) 1 that LINE OUT voltage I llight. and R segments is 360mV -gdBV. around OdB should , I L fade out almost simur- i _l _ taneousty. I A E1,J#F* ,.t iHlT:lI . i - %:1:i: loo,;:Hp Ratins i .*1 li-5Lnso+T

37、nrrraillp;c.v.n,r.- rnrc israseolust* -Fjg: -noiu.trotn,1 lation level TP6 LMaximum (VR107) lt-t tO oscitlation Set VRl 19 and 12O all I 1 output is I the way to the teft. I t ;r. OUT ,TAPE (REC at minimum), set lFi102 (R) i 13mV imize bias leak. I I I BIAS ADJUST to maxi- I l , 1 mum and measure bi

38、as I i I I leak at LINE OUT when I i I - - -t- - - -l 4t i1I tt tilt -l- - tlrililnun 3 ,BrAS Leak MErAL ir-rruE n c.v ru. tIFg_ IHL;tflttped -:19119q -!3;,1.r; -lnJr,- *.rn,ni ll I I I recording and monitoring I I AC-223 INPUT LIN E A.C.V.M. lsrcNnr- T (1 kHz, 1 0kHz, -20d B l simultaneouslv TAPE m

39、ode) by using a metal the standard level) 3-rRecord the signal and adjust so that the same level as the above ilr level is obtained. I rRecord and playback a l kHz (-20d8) signal and read the level. Record and playback a 10kHz (-20dB) signal and adjust so that the same level as the above :-!, level

40、is obtained Set METAL (AC-712) and Derform BIAS TEST. Frequency response should satisfy Fig. N. Ilirrili. i i ii.ii r* lguency is used for adiustment. Bias ,191:ll may indi- Each adjustment in Steps4and6should be complited. Con- I simultaneously TAPE I I I I mode) by using a metal I I litape.lirrlll

41、taneil ia-n*Jis-iara-firvF-e.cl.rv. inic l,r,swilrglaiio s -ft*iri lr_jlto.sae - -rh;r. I Levet ilNpuT OUT TAPE 1 the midpoint. lVR1t2 (R) i lthis unir (Through) SIGNAL _-NR-+ ,zApplyalkHzsinewavel (equivat, i L ,(lkHz, iLtNE tnudio oFF I sisnal from LINE lN so I i vn). tt t i 1-20d8) jlN ifrequency

42、 I I that LINE OUT voltage I L used, stir i I I j osilaror i I is 36mV (-29dBV). I lin revet r * r-l ) 4 Becording tAC-712 ILINE A.C.V.M. REC 1,r,SetVR119and 120as lVR11l L) 10.5d8 Thereferencetapeof Level INPUT OUT TAPE the midpoint. lVR112 (R) this unit is AC-720 (Throush) 99.ryAL - -ryl_* ,zApply

43、-alkHzsine-waveI (equivalenttoTDK. I ilii (equivalent to TDK- MA). lf other tape is j used, slight difference j in level results. I I 1(Through) TSIGNALT_ -L_lNR-+ jZAnOlvalkHzsinewave | (equivalentt, i L ,(lkHz, iL|NE tnudio oFF I sisnal f rom LINE lN so I i MA). lf othe I i 1-20d8) jlN ifrequency

44、I I that LINE OUT voltage i used, stight d t i 1-20d8) 1lN lfrequency I I that LINE OUT voltage I i used, slight difference i I t lositlaror i l.ts36mv.(-29dBv). I inrevel results. A I 1. I i i i l1:t.ii;:l1ti#ll i i i issfxt.,lfifi:i*nl I i I Iswitched. I _-T-r.f-_ jHecorolng A.v-t tz LINE lA.U.v.M

45、. iHEU l.l.Uonlrrm tne lKHz re- LVR119 (Ll I Frequency IASORBiT signal is jBIAS TINPUT OUT I jTAPE cord/playback level VR120 (R) response lltHz and 10kHz, use (METAL) ls-tGNAL I I i1. i. lslg 1): I tloulg saj- iql.kf , sisnar.and a I I I iiiita. I I i i l=:- -i=- i i .- -+-f:- -f- - -r -1 5 Recordin

46、g AC-712 LlNEIA.C.V.M. REC lil.Applya lkHzsinewave 1VR121 (L) l+0.5d8 Eachadiustmentin i Level (dbx) INfUT OUT I TAPE I signal from LINE lN so ,VR122 (R) step 4 shoutd be I i9.ryAl_-_t_ry.R* thatLI.NEoUTvoltase I ompteted. I 1kHz, jttwE laraio rdbx I is 36mV (-29dBV). I 1 l -2odB) I lN lf.equency ,

47、z Record the signal and 1 I losillator adiust so that there is I I I j I I I I notevet differsncewhenl I l I I I I I sounce/rRpeis 1 I I I r j I I I li*ittJ I I r r - - - :-;+rrruEincnnn il;:_ -l*t-frtirH.- ty.ltgttlir.o*ru l,prt!,rrr, -1 6 Recordins LC/ 12 lTnPe cord/playback level VR120 (R) response jttHz ana 10kHz, u iNR * I (Step 4). I should sat- la lkHz signal and a ritH., - 1 | lcjir :a,h-5.iuno prayback a j ;js.t iriti, *r lokHz, I 1 I j 1OkHz(-20dB) signal I fad.iustinsrecording/ i-20d8) i I I l:*i1:l:,*:*:1 I l*:l:li:-:v same level as the above I response and confirm