Sansui-SC636-tape-sm 维修电路原理图.pdf

7IIISERVICE MUALSTEREO CASSETTE TAPE DECK$tful G-g3giiIIIiIII; VRadioFans.CN 收音机爱 好者资料库arsc-636This service manual is designed for service engineers to repair,adjust, maintain and order the replacement parts of the SC-636 cor-rectly. When ordering the parts, use the stock number and partsname specifically referring to the Exploded Views, Parts Location andParts Lists.For general usage and maintenance of the unit, please refer to theOperating lnstructions attached with the unit.TABLE OF GONTENTSSection Title Page1. SPECIFICATIONS 22. BLOGK DIAGRAM ANDLEVEL DIAGRAMS 32-1. BlockDiagram . 32-2. Level D iugru rs 43. ADJUSTMENTS 53-1. Head Ad justment 53-1-1. REa/P B Head Ad justment 53-1-2. Erase Adjustment 53-2. Playback Level Adjustment 53-3. High Frequency Equalization Adjustment 53-4. VU Meter Level Adjustment 53-5. Recording Bias Adjustment 53-5-1. Setiing TAPE SELECTOR Switchto NOnUnl 53-5-2. Setting TAPE SELECTOR Switchto CHROMIUM 63-6. REC/PB Level Adjustment 63-6-L Setting TAPE SELECTOR Switchto NORMAL 63-6-2. Setting TAPE SELECTOR SwitchtoCHROUIUM . 73-7. DolbY Circuit Adiustment 73-8. B ias MPX F ilter Ad justment 73-9. Pinch-roller Pressure Adjustment 73-l0. Torque Adjustment 74. TROUBLESHOOTING CHART 84-1. TROUBLESHOOTING ON THEELECTRICALSECTION .84-1-L Troubleshooting on PowerSupply Section 84-1-2. Troubleshooting on RecordingSystem 8, 94-1-3. Piayback System Troubles 9, 104-1-4. Troubles in Both RecordinglPlaybackMode. 1OSection Title Page4-1-5. Auto Shut-off Circuit Troubles 104-1-6. Dolby Circuit Troubles 104-2. TROUBLESHOOTINC ON THEMECHANICAL SECTION .114-2-L PLAY lnoPerative 114-2-2. FAST FORWARD lnoperative L24-2-3. REWIND lnoPerative I24-2-4. PAUSE lnoPerative L24-2-5. lncorrect Tape Speed L24-2-6. Excessive Wow and Flutter L24-2-T.lncorrectBrake L25. PARTS LOCATIONS AND PARTS LISTS.135-1. GA-1191 REC/PB AmPlifierCircuit Board. . 13, L45-2. GA-1190 Power SuPPIY andAutoStoPCircuit Board 155-3. G-1 167 Dolby Circuit Board L6, L75-4. G-1160 Switch Circuit Board I75-5. G-1180 Cds Circuit Board L75-6. C-1185 Fuse Circuit L75-7. GA-1189 Leve! Circuit Board 185-8. OtherPartsList 186. DISASSEMBLY WITH EXPLODED VIEWSAND PARTS LISTS . .196-1. Disassembly of the Cabinet andEtectrical Sections . .19,206-2. DisassemblY of the Mechanism(Top View) 2L,226-.3. Disassembly of the Mechanism(Bottom View) 23,247. SCHEMATIC DIAGRAM . ,258. REPLACEMENT OF MAIN PARTS. . . .269. PACKING LIST .2610. ACCESSORY PARTS LIST. . . .26rr/,RadioFans.CN 收音机爱 好者资料库1. SPEGIFICATIONSvvTRACK . .4-track (2-ch. stereo)TAPE SPEED .4.Bcm/sec (1 % ips.)TAPE STAN DAR D PH IL IPS cassette standardHEADS . . REC/PB ferrite headERASE ferrite headMOTOR hysteresis synchronousrypeTAPE DRIVINC SYSTEM . . belt driving systemWOW AND FLUTTER within 0.12% (W.R.M.S.)TAPE SPEED ACCURACY . .within +1.5%FAST WIND TIME within 70 seconds (C-60)FREQUENCY RESPONSE (REC/PB)NORMAL (1. H) TAPE. . . . 30 to 13,000H2 (35 to10,000H2 -f- 3.0d B)CHROMIUM TAPE.30 to16,000H2 (35 to13,000H2 i 3.0d8)srcNAL TO NOrSE RATIO (REC/PB)CHROMIUM TAPE (without dolby noise reductioneffect) . . better than 50dB (weighted)DOLBY NOISE REDUCTION EFFECT. . better than BdB (above 5kHz)CHANNEL SEPARATION . . better than 3BdB at 1,000H2ERASURE FACTOR. . . . more than 60dB at 1,000H2TNPUT SENSTTIVITY AND |MPEDANCE (OVU, 1,000H2)MIC (LEFT, RICHT) . .0.5mV 600,l0k0MIC (Cf NTER) 0.5mV 600-l0k0LINE . .70mV 100kODIN . .14mV 30kOOUTPUT LEVEL (OVU 1,000H2)LINE i. .0.56VDIN .0.s6vHEADPHONES .0.12mW/BOBIAS FREQUENCY .B5kHzOTHERSSEMICONDUCTORSTRANSISTORS O35FETs . . 2ZENER DIODES. 3DIODES. .11VARISTORS. . BCdS 1POWER VOLTAGE 100, 117, 220,240V, 50160zPOWER CONSUMPTION . .22W (rated)DIMENSIONS 408mm (1 6%) W1lBm m (41%) H2g5rn m (11%) DWE IGHT 6.7kg (14.8 !bs) net.B.6kg (19.0 lbs) Packed* Design and specifications subiect to change without notice forim prove ments.2qiG*-o3G2, BLOCK DIAGRAM AND LEVEL DIAGRAMS2-L Block DiagramMrcJ701J703CENTER MICREC/PB HEII)G-11504G-1191l-eVet- COttfnOt-CIRCUITloK EQ, VR02G-1160ASWITCH CIRCUITREC/PB AMP CIRCUITt-l-Ir.uJDOLBY CIRCUIT!2=rFzroo(o.;) i- s7- REWl+.rr! r-:- r77 i-l SS- pLAy: i c =1-Cds CIRCUITc+raoG-1160A11SWITCH CIRCUIT1. NORMAL I.2. CHROMIUM2.r-lI *=!l(r(=.I A-ElI LJ-r- It:PAUSE 54 F.F SW SPOWER 55 REW SW 57I. OFF PLAY SW 582. ONERASE HEADXG-1190D605- Pr-rw ER SrrPFPOW ER SU PPLY CIRCU ITPLAY REC SIo-L TAPE SELECTOR S2o-f OOI.BYI . PLAY2. RECN.R. S3o, bOUTIN3Gb2-2. level Diagrams*Each number (Oo, O,O ) indicated in LevelDiagrams undermentioned corresponds to the numberin Block Diagram.*Each number , , .- Recording Level*Each number O, O, O. . .- playback Level1. MIC/LINE volume control. . . . Maximum2. CENTER MIC volume control Maximum800mV(3dB)70mV (- 18dB )l5mV(-3l.5dB)5mV (-41dB )0.5mv(-62d8)Mtc800mV(3dB)l0mv(-35d8)SmV(-41d8)0.5mV(-62d8 )3. INPUT.1kHz Sine Wave(output impedanceaudio oscillator)Note: Each vottage value is for referenceby a VTVM. ln some recorders, the actuatis in minor difference from the referenceof 600O at anand measuredvoltage valuevalue.RECORDIIilNGOdB:560mV560mV(OdB ) s6omv(0dB ) 560mV(0dB )580mV(0.2d8 )0mV(-7dB)mV(-9dB)62mY(-l9dB )N0RMAL tape560mv(OdB) 560mv(OdB) 560mv(0dB) 580mv(0.2d8) 560mv(OdB)I lOmV(-l4.8dB)62mV(-l9dB),CHR0ttllUM tape80mV(-l7dB)65mV (l 8.7d8 ).4.tK0dB:560mVLINE IN28mV(-26d8)4sc-6363. ADJUSTMENTS*The List of Sansu i Test TapesNCT-F63SCT-F6363HzPlayback f requency checkNCT.FI KSCT.Fl KlkHzPlayback f requency checkNCT.FlOKSCT.FlOK10kHzPlayback f requency check,REC/PB head adjustmentNote: The above test tapes in each colu m n can be used in:i ;j,:l ii :J,li; l,1:i,:n ;Jdifferent recorded levels between NCT- and SCT- tapes.3-1 . Head Adiustment (See tig. 3-1 )3-1-l . REC/PB Head Adjustment1) Connect a VTVM to the LINE OUTPUT terminals(1, R-ch).2) Play back the 10 kHz test tape (SCT-F10K).Adjust the azimuth adjusting screw for the maximumreading on the VTVM at both channels.3-l -2. Erase Head Adiustment1) Any adjustment on the erase head is not necessary.* Confirm only that recorded signals on one channelof tape are completely erased and ones on anotherchannel are not.Fig. 3-13-2. Playback Level Adiustment(See Fig. 3-3)1) Connect a VTVM to the LINE OUTPUT terminals(1, R-ch).2) Play back the 400 Hz test tape (SCT-L 400).Adjust VR03 for L-ch and VR04 for R-ch on G-1191 sothat the output level of playback signal on VTVMwill indicate 560mV at 400H2.* Play back the 63 Hz, l kHz and 10 kHz test tapes(SCT-F63, SCT-F1 K and SCT-F1OK) and make surethat the both outputs are within 0+ 3dB against thatof 1kHz.3-3. HiSh Frequen cy EqualizationAdiustment (See Fig. 3-3)1) Connect a VTVM to the LINE OUTPUT terminals (1,R-ch)2) Play back the lkHz test tape (SCT-F 1K) and 10kHztest tape (SCT-F 10K)Make adjustment of VR01 for L-ch and VR02 for R-chon F-1191 so that the difference of output levels be-tween lkH.z and 10kH z will be+08.3-4. VU Meter Level Adiustment(See Fig. 3-3)1) Set the MIC/LINE LEVEL volumes to maximum.2) Connect a VTVM to the LINE OUTPUT terminals(1, R-ch).3) Supply the l kHz signal from an audio signal genera-tor to the LINE INPUT terminals (1, R-ch).4) Push on the PAUSE button and set the unit in therecord mode after setting a Normal test tape (SCT-FC86).5) Adjust the level volume of the audio signal generatorfor obtaining 560 mV on the VTVM.6) Adjust VR09 for L-ch and VR10 for R-ch on C-1191to obtain 0dB on the VU meters.3-5. Recording Bias Adiustment(See Fig. 3-2)3-5-1 . Setting TAPE SELECTOR Switch toNORMAL1) Set the MIC/LINE LEVEL volumes to maximum.2) Connect a VTVM to the LINE OUTPUT terminals(1, R-ch).3) Supply the l kHz signal from an audio signal genera-tor to the LINE INPUT terminals (1, R-ch).4) Push on the PAUSE button and set the unit in therecord mode after setting a Normal test tape (SCf-rc86)5) Adjust the level volume of the audio signal genera-tor for obtaining 560mV on the VTVM.* Make sure that the reading of the VU meter is 0dB.YDescriptionNCT-L4OOSCT-L4OO400H2Playback level adjustment,VUmeter level checkNCT-S3KSCT-S3K3k HzSpeed, wow & fluttercheckNCT-FC86SCT.FC86Record i n g bias adj ustment,REC/PB level adjustment,All-over frequency (REC/PB) checkNCT.FCRSCT.FCR(A)(B)YYv5v6) Change the lkz signal from 560mV to 56mV( - 2od B).Push off the PAUSE button and record.Then, change the signal from l kHz to 10kHz (56mV)and record.7) Play back the lkHz and 1OkHz,signal, then confirmthat difference of output levels between lk1z and10kHz is +0dB (nanrely, confirm that the outputlevels of both signals wh ich must be 56mV on VTVMres pect ive ly).B) If the level of 10kHz signal is under 56mV, as com-pared with the level of 1kHz, turn VR0l for L-ch andvR04 for R-ch on c-1190 counterclockwise fromconductor side.lf it is over 56mV, turn them clockwise from con-ductor side. When adjusting the above, repeat thesteps 6),7) until the difference of both output levels(1kHz and 10kHz) are OdB (56mV) on VTVM.3-5-2. Setting TAPE SELECTOR switch toCHROMIUM3-6. REC/PB Level Adiustment(See Fig. 3-3)3-6-1 . Setting TAPE SETECTOR switch toNORMAL1) Set the MIC/LINE LEVEL volumes to maximum.2) Connect a VTVM to the LINE OUTPUT terminals (1,R -ch).3) Supply the l kHz signal from an audio signal gnera-tor to the LINE INPUT terminals (1, R-ch).4) Push on the PAUSE button and set the unit in therecord mode using a Normal test tape (SCT-FCB6).5) Ad just the level vo lu me for obtain ing 56mV o n theVTVM.6) Push off the PAUSE button, then record the lkHzsignal.7) Play back the lkHz signal and confirm the outputlevel of each channel which must be 56mV onVTVM.B) lf the indication of output level on each channel isunder 56mV, turn VR05 for L-ch and VR06 for R-chon C -1191 counterclockwise or if it is over 56mV,turn them clockwise from conductor side so that theoutput level 56mV may be obtained.Repeat the above steps 6),7) a few times until theindication on VTVM will be exactly 56mV.1)2)3)4)Perform step 1) through 3) of 3-5-1 .Push on the PAUSE button and set the unit in therecord mode using a Chromium test tape (SCT-FCR).Perform steps 5), 6) and 7) of 3-5-1.lf the level of 10kHz signal is under 56mV (OdB) onVTVM, turn VR03 for L-ch and VR02 for R-ch on C-1190 counterclockwise from conductor side.lf it is over 56mV, turn them clockwise from con-ductor side. When ad justing above, repeat the step3) until the difference of output levels (1kHz and10kHz) are OdB (56mV) on VTVM.Fig. 3-2vR03 vR01 vR02 vR04Fig. 3-3L-chR-chG- 1191vR09VU level- -li ilo3l- -lf- - -li iLo4t- - -llrr?iqffiH13,.,i.$vr,:,.,6sG-6363-6-2. Setting TAPE SELECTOR switch toCHROMIUM1) Perform steps 1) throrgh 3) of 3-6-1.2) Push on the PAUSE button and set the unit in therecord mode using the Chrom iu m test tape (SCT-FCR).3) Perform steps 5), 6) and 7) of 3-6-1.4) lf the indication of output level on each channel isunder 56mV, turn VR07 for L-ch and VROB for R-chon C-1191 counterclockwise or if it is over 56mV,turn them clockwise from conductor side so that theoutput level 56mV may be exactly obtained.Repeat the above step 3) a few times until theindication on VTVM will be exactly 56mV.3-7. Dolby Circuit Adiustment(See FiS. 3-4)1) Set the MICiLINE LEVEL volume to maximum andDOLBY switch to OUT.2) Turn VR01 clockwise (viewed from the bottom side)and VR02 counterclockwise (viewed from the bottomside.)3) Connect a VTVM respectirely between the terminal01 and ground for L-ch, and terminal 04 and groundfor R-ch on F-1 167.4) Supply the 5kHz signal from an audio signal genera-tor to the LINE INPUT terminals (1, R-ch).5) Push on the PAUSE button and set the unit in therecord mode after setting a Normal test tape (SCT-FC86)6) Adjust the output level volume of the audio signalgenerator for obtaining 17.SmV on the VTVM.7) Cround TP01 and TP02 and set the DOLBY switch totN.B) Adjust VR03 for L-ch, and VR04 for R-ch on F-1167until the VTVM reads 55.3mV (+10d8) higher posi-tion from 17.smV.9) Disconnect TP01 and TP02 from ground.10) Adjust VR01 for L-ch, and VR02 for R-ch on F-1167until the VTVM reads 4O.9mV (-2dB) lower posi-tion from 55.3mV.11) Cround TP01 and TP02 again.Make sure that the VTVM connected between theterminal 01 and ground for L-ch, and the 04 andground for R-ch reads 55.3mV (+ 2dB) higher posi-tio n.tig. 3-43-8. Bias MPX Filter Adiustment(See tig. 3-3)*When replacing the RE CIPB amp circuit board (C -1191),adjust the Bias MPX Filter.1) Set the Mlc/LINE LEVEL volumes to maximum.2) Connect a VTVM to the LINE OUTPUT terminals(1, R-ch).3) Srpply the 19kHz,10mV signal from an audio signalgenerator to the LINE INPUT terminals (1, R-ch).4) Push on the PAUSE button and set the unit in therecord mode after setting a Normal test tape (SCT-FC86).5) Adjust 103 for L-ch and 104 for R-ch on C-1191 orobtaining the minimum reading on VTVM.3-9. Pinch-roller Pressure Adiustment(See Fig. 3-5)*After pushing on the PLAY button with or withoutcassette tape, perform the following procedures (pow-er switch ON).1) Hook the spring scale at point of the roller arm asshown in Fig. 3-5.2) Pull the spring scale eventually to the arrow direc-tion until the pinch-roller stops running.3) SIide the spring retainer (Part name, Hook, Pinch-roller sprin g) bY loosing the screw so that the scaleindicates 330+308.4) Screw it up, then confirm that no considerable varia-tion of the pressure indication on the scale is in-cluded in PLAYBACK and STOP process.tig. 3-53-10. Torque Adistment*No any torque adjustments are necessary.Each torque is fixed as follows:Take-up torque (PLAYBACK) . more than 3$g-cmTake-up torque (FAST FORWARD) . .60-110g-cmTake-up torque (REWIND) 60-110g-cmYYYYTPOlmvR01capstan shaftpinch-rollerroller armspring retainerVRO3vRo2 vRo4 c4. TROUBLESHOOTING CHART4-1. TROUBLESHOOTING ON THE ETECTRICAT4-1-1 . Troubleshooting on Power Supply SectionSymptomCheck Point1-1. Output 19V not supplied to point on C-11901) VU lamps not Iighted2) VU lamps Iighted1-2. Excessive hum4-1-2. Troubleshooting on Recording System2-1. Output 560mV not supplied toLINE OUTPUTB0mV (chromlum tape), 65mV (normal tape)SECTIONCau seDefective power cord ptugPower cord opensDefective power switch 55Power fuse F01 openDefective voltage selecto r, PU7O1Defective power transformer, T701Def ective d io de, D601 ., D 604 (10D -1 ) o nG-1190Defective transistor, TR601 (2SC1061) onG-1190Defective zener d iode, 2D601 (RD-19A)o n C-1190Defective C60 4 (1OO1F 25V), C603 (100f225V), C6A2 Q200pF 35V) on C-1190Defective transistor, TR601 (2SC1061) onG-1190Due to magnetic f lux from powertransformerlmperfect contact of LINE lN Jacklmperfect contact of 51-e (S1 -f) on C-1191Defective TR01, TR03 (TR02, TR04) onc-1191lmperfect contact of VR01 (VR02) onG-1189lmperfect contact of MIC Jacklmperfect contact of CENTER MIC JackDefective TR60l (TR602) on C-1189I m perf ect co n tact of VR601 o n C -1 1 89lmperfect of 51 -a (S1-c) on F-1191Defective TR05, TR07, TR09 (TR06, TROB,TR10) o n C-1191L01, 103, (L02, 104) on C-1191 openI mperfect co ntact of 51 -b, 51 -d, Sl -g, 51-ho n C-1191Defective TR13 (TR14) on C-1191I mperfect co ntact of headpho ne