Sansui-SC636-tape-sm 电路图 维修手册.pdf

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1、7 I I I SERVICE MUAL STEREO CASSETTE TAPE DECK $tful G-g3g i i I II i I II ; V RadioFans.CN 收音机爱 好者资料库 ar sc-636 This 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

2、and parts name specifically referring to the Exploded Views, Parts Location and Parts Lists. For general usage and maintenance of the unit, please refer to the Operating lnstructions attached with the unit. TABLE OF GONTENTS Section Title Page 1. SPECIFICATIONS 2 2. BLOGK DIAGRAM AND LEVEL DIAGRAMS

3、3 2-1. BlockDiagram . 3 2-2. Level D iugru rs 4 3. ADJUSTMENTS 5 3-1. Head Ad justment 5 3-1-1. REa/P B Head Ad justment 5 3-1-2. Erase Adjustment 5 3-2. Playback Level Adjustment 5 3-3. High Frequency Equalization Adjustment 5 3-4. VU Meter Level Adjustment 5 3-5. Recording Bias Adjustment 5 3-5-1.

4、 Setiing TAPE SELECTOR Switch to NOnUnl 5 3-5-2. Setting TAPE SELECTOR Switch to CHROMIUM 6 3-6. REC/PB Level Adjustment 6 3-6-L Setting TAPE SELECTOR Switch to NORMAL 6 3-6-2. Setting TAPE SELECTOR Switch toCHROUIUM . 7 3-7. DolbY Circuit Adiustment 7 3-8. B ias MPX F ilter Ad justment 7 3-9. Pinch

5、-roller Pressure Adjustment 7 3-l0. Torque Adjustment 7 4. TROUBLESHOOTING CHART 8 4-1. TROUBLESHOOTING ON THE ELECTRICALSECTION .8 4-1-L Troubleshooting on Power Supply Section 8 4-1-2. Troubleshooting on Recording System 8, 9 4-1-3. Piayback System Troubles 9, 10 4-1-4. Troubles in Both Recordingl

6、 PlaybackMode. 1O Section Title Page 4-1-5. Auto Shut-off Circuit Troubles 10 4-1-6. Dolby Circuit Troubles 10 4-2. TROUBLESHOOTINC ON THE MECHANICAL SECTION .11 4-2-L PLAY lnoPerative 11 4-2-2. FAST FORWARD lnoperative L2 4-2-3. REWIND lnoPerative I2 4-2-4. PAUSE lnoPerative L2 4-2-5. lncorrect Tap

7、e Speed L2 4-2-6. Excessive Wow and Flutter L2 4-2-T.lncorrectBrake L2 5. PARTS LOCATIONS AND PARTS LISTS.13 5-1. GA-1191 REC/PB AmPlifier Circuit Board. . 13, L4 5-2. GA-1190 Power SuPPIY and AutoStoPCircuit Board 15 5-3. G-1 167 Dolby Circuit Board L6, L7 5-4. G-1160 Switch Circuit Board I7 5-5. G

8、-1180 Cds Circuit Board L7 5-6. C-1185 Fuse Circuit L7 5-7. GA-1189 Leve! Circuit Board 18 5-8. OtherPartsList 18 6. DISASSEMBLY WITH EXPLODED VIEWS AND PARTS LISTS . .19 6-1. Disassembly of the Cabinet and Etectrical Sections . .19,20 6-2. DisassemblY of the Mechanism (Top View) 2L,22 6-.3. Disasse

9、mbly of the Mechanism (Bottom View) 23,24 7. SCHEMATIC DIAGRAM . ,25 8. REPLACEMENT OF MAIN PARTS. . . .26 9. PACKING LIST .26 10. ACCESSORY PARTS LIST. . . .26 r r/ , RadioFans.CN 收音机爱 好者资料库 1. SPEGIFICATIONS v v TRACK . .4-track (2-ch. stereo) TAPE SPEED .4.Bcm/sec (1 % ips.) TAPE STAN DAR D PH IL

10、 IPS cassette standard HEADS . . REC/PB ferrite head ERASE ferrite head MOTOR hysteresis synchronous rype TAPE DRIVINC SYSTEM . . belt driving system WOW 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

11、 (1. H) TAPE. . . . 30 to 13,000H2 (35 to 10,000H2 -f- 3.0d B) CHROMIUM TAPE.30 to16,000H2 (35 to 13,000H2 i 3.0d8) srcNAL TO NOrSE RATIO (REC/PB) CHROMIUM TAPE (without dolby noise reduction effect) . . better than 50dB (weighted) DOLBY NOISE REDUCTION EFFECT . . better than BdB (above 5kHz) CHANNE

12、L SEPARATION . . better than 3BdB at 1,000H2 ERASURE FACTOR. . . . more than 60dB at 1,000H2 TNPUT SENSTTIVITY AND |MPEDANCE (OVU, 1,000H2) MIC (LEFT, RICHT) . .0.5mV 600,l0k0 MIC (Cf NTER) 0.5mV 600-l0k0 LINE . .70mV 100kO DIN . .14mV 30kO OUTPUT LEVEL (OVU 1,000H2) LINE i. .0.56V DIN .0.s6v HEADPH

13、ONES .0.12mW/BO BIAS FREQUENCY .B5kHz OTHERS SEMICONDUCTORS TRANSISTORS O35 FETs . . 2 ZENER DIODES. 3 DIODES. .11 VARISTORS. . B CdS 1 POWER VOLTAGE 100, 117, 220,240V, 50160z POWER CONSUMPTION . .22W (rated) DIMENSIONS 408mm (1 6%) W 1lBm m (41%) H 2g5rn m (11%) D WE IGHT 6.7kg (14.8 !bs) net. B.6

14、kg (19.0 lbs) Packed * Design and specifications subiect to change without notice for im prove ments. 2 RadioFans.CN 收音机爱 好者资料库 qi G*-o3G 2, BLOCK DIAGRAM AND LEVEL DIAGRAMS 2-L Block Diagram Mrc J701 J703 CENTER MIC REC/PB HEII) G-11504 G-1191 l-eVet- COttfnOt- CIRCUIT loK EQ, VR02 G-1160A SWITCH C

15、IRCUIT REC/PB AMP CIRCUIT t- l- I r.u J DOLBY CIRCUIT !2 = rF z ro o (o . ;) i- s7- REW l+.rr! r-:- r77 i-l SS- pLAy : i c =1- Cds CIRCUIT c+rao G-1160A 11 SWITCH CIRCUIT 1. NORMAL I. 2. CHROMIUM 2. r-l I *=!l (r(=. I A-El I LJ-r- I t: PAUSE 54 F.F SW S POWER 55 REW SW 57 I. OFF PLAY SW 58 2. ON ERA

16、SE HEAD X G-1190 D605 - Pr-rw ER SrrPF POW ER SU PPLY CIRCU IT PLAY REC SIo-L TAPE SELECTOR S2o-f OOI.BY I . PLAY 2. REC N.R. S3o, b OUT IN 3 G b 2-2. level Diagrams *Each number (Oo, O,O ) indicated in Level Diagrams undermentioned corresponds to the number in Block Diagram. *Each number , , .- Rec

17、ording Level *Each number O, O, O. . .- playback Level 1. MIC/LINE volume control. . . . Maximum 2. CENTER MIC volume control Maximum 800mV(3dB) 70mV (- 18dB ) l5mV(-3l.5dB) 5mV (-41dB ) 0.5mv(-62d8) Mtc 800mV(3dB) l0mv(-35d8) SmV(-41d8) 0.5mV(-62d8 ) 3. INPUT.1kHz Sine Wave (output impedance audio

18、oscillator) Note: Each vottage value is for reference by a VTVM. ln some recorders, the actuat is in minor difference from the reference of 600O at an and measured voltage value value. RECORDI Iil NG OdB:560mV 560mV(OdB ) s6omv(0dB ) 560mV(0dB ) 580mV(0.2d8 ) 0mV(-7dB) mV(-9dB) 62mY(-l9dB ) N0RMAL t

19、ape 560mv(OdB) 560mv(OdB) 560mv(0dB) 580mv(0.2d8) 560mv(OdB) I lOmV(-l4.8dB) 62mV(-l9dB) ,CHR0ttllUM tape 80mV(-l7dB) 65mV (l 8.7d8 ) .4. t K 0dB:560mV LINE IN 28mV(-26d8) 4 sc-636 3. ADJUSTMENTS *The List of Sansu i Test Tapes NCT-F63SCT-F6363HzPlayback f requency check NCT.FI KSCT.Fl KlkHzPlayback

20、 f requency check NCT.FlOKSCT.FlOK10kHz Playback f requency check, REC/PB head adjustment Note: The above test tapes in each colu m n can be used in :i ;j,:l ii :J,li; l,1:i,:n ;J different recorded levels between NCT- and SCT- tapes. 3-1 . Head Adiustment (See tig. 3-1 ) 3-1-l . REC/PB Head Adjustm

21、ent 1) 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 maximum reading on the VTVM at both channels. 3-l -2. Erase Head Adiustment 1) Any adjustment on the erase head is not necessary. * Confirm only that

22、 recorded signals on one channel of tape are completely erased and ones on another channel are not. Fig. 3-1 3-2. 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 o

23、n G-1191 so that the output level of playback signal on VTVM will 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 sure that the both outputs are within 0+ 3dB against that of 1kHz. 3-3. HiSh Frequen cy Equalization Adiustment (See

24、 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 10kHz test tape (SCT-F 10K) Make adjustment of VR01 for L-ch and VR02 for R-ch on F-1191 so that the difference of output levels be- tween lkH.z and 10kH z will be+08. 3-4. VU Meter Lev

25、el 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 the record mode afte

26、r setting a Normal test tape (SCT- FC86). 5) Adjust the level volume of the audio signal generator for obtaining 560 mV on the VTVM. 6) Adjust VR09 for L-ch and VR10 for R-ch on C-1191 to obtain 0dB on the VU meters. 3-5. Recording Bias Adiustment (See Fig. 3-2) 3-5-1 . Setting TAPE SELECTOR Switch

27、to NORMAL 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 the record mode after setting a Normal

28、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. Y Description NCT-L4OO SCT-L4OO 400H2 Playback level adjustment, VUmeter level check NCT-S3K SCT-S3K 3k Hz Speed, wow ,H:iHEADPHONE J

29、ack present at LINE OUT t-25. L26. 2-3. VU meter inoperative I 1) Output present at LINE OUT 27. lmperfect G-1191 28. Defective 29. Defective 30. Defective contact of VR09 (VR10) on TR15 (TR16) on C-1191 D01 , D03 (D02, D04) on C-1191 VU meter, M701 (M702) a sc-636 2-4. 2-5. SymptomCheck Point Recor

30、d ing syste m inoperative (Output present at LINE OUT) Defective record ing o n C-1191 1) Output 250mV (chromium tape),200mV (normal tape) absent at terminul EJ (32) on C-1191Defective VR05, VR07 (VR06, VR0B) on G-1191 lmperfect co ntact of Tape Selector switch, 52-a,f on C-1160A Defective TR11 (TR1

31、 2) on C -1191 Open 105 (106) on C-1191 Defective OSC, Block on C-1190 lmperfect contact of VR01, VR03 (VR02, VR04) on C-1190 lmperfect contact of Tape Selector switch, S2-b, d, e, f on C-1160A Defective RECI?B head, YC-303 (ln case of no output at both REC and PLAYBACK) No output at REC and PLAYBAC

32、K Open REC lamp, PL705 lmperfect contact of REC lamp and socket lmproper setting of Tape Selector switch lmproper bias current Defective recording amp. D irty head Loose adjustment of erase head Dirty head Defective head Defective oscillator block Defective REC/PB head I m perf ect co ntact of S1-b

33、(St -d) o n C -1191 Defective TR01, TR03 (TR02, TR04) on G-1191 lmperfect contact of VR03 (VR04) on c-1191 lmperfect contact of 51 -g (S1 -h) on C-1191 Defective TR05, TR07, TR09 (TR06, TROB, TR10) on C -1191 Open L01, 103 (102, L04) on G -1191 31. Def ective TR01, c-1167 Cause TR03 (TR02, TR04) o n

34、 v r , 2) 3) Output BOmV (chromium tape),65mV (normal tape) absent at terminat (30) on C-1160A 1 Output 19.5V absent at terminal 4 on G-1190-i6 32. 33. 37. 39. 40. 2-6. Recording system and Oscillator circuit operative 2-7. lmperfect contact of tape and head 2-8. Record lamp not lighted | 1) Record

35、ing syste m operative 2-9. Excessive distortion in recording 2-10. No erasing 4-nl-3. Playback System Troubles 3-1 . Output 560mV absent at LINE OUT ) Output 10mV absent at the collector of TR03 (TR04) on C-1191 41 t_; 43. 44. 45. 46. 47. 48. 49. 50. 51 . 52. 53. 2) Output 560mV absent at terminal |

36、 (20) on C -1191 *to page 10 54. 55. 56. 9 Y Y Y v SymptomCheck Point *frgm page 9 | -3) Output560mVabsentatL|NEOUT Cause I mperfect co ntact of 51 -k (St - l) o n C-1191 Defective TR01, TR03 (TR02, TR04) on c-1167 See 2-2 in Troubleshooting on Recording Syste m See 2-3 in Troubleshooting on Recordi

37、ng Syste m r- 58. I sg. 3-2. 3 -3. Output 110mV absent at HEADPHONE Jack No indication on VU meter Dolby circuit i noperative (S/N ratio not improved) lncorrect f req uency respo nse (Excessive or less high-frequency signals) 61. 60. 73. 74. 75. 76. 77. 4-1-4. Troubles in Both RecordinglPlayback Mod

38、e 4-1 . Less high-frequency signals 4-2. Distorted or weak sound 4-3. Excess ive n o ise 62. D irty head 63. Worn-Out head 64. Loose head position 65. Loose ad justment of head 66. Loose adjustment of equ alizer amp. 67. Defective pressure pad of cassette tape 68. Defective Cassette tape 69, Over in

39、put level 70. Dirty head 71. Loose adjustment of Head 72. lmproper setting of Tape Selector switch (NORMAL or CHROMIUM) in recording Defective capacitor in amplifier Excessive tape h iss Defective transistor on amp. section Defective capacitor (resistor) or imperfect co ntact of vo lu me co ntro I D

40、ue to externa I no ise Magnetized head78. 4-l-5. Auto Shut-off 5-1 . Auto Shut-off Circuit Circuit Troubles inoperative79. Defective CdS lamp MKY-SH on C-1180 80. Defective TR02, TR03, TR04 on C-1190 81 . Defective plunger solenoid P5701 82. Defective D606, D607 , 2D602 o n C-1190 4-1-6. Dolby Circu

41、it Troubles As one Dolby circuit is actuated in both Recording and Playback mode by switching, the same type of trouble may occur in both modes. ln case Recording and Playback are normal, but Dolby circuit does not unction, it means that TR01, TR03 (TR02, TR04), 51-K (S1-l), S3-a (S3-b) are normal.

42、6-1. 6-2. 83. Defective TR05, TR07 (TR06, TR0B) on c-1167 84. Defective FET01 (FET02) on C-1 167 85. Defective or loose ad justment of VR01 (VR02) and VR03 (VR04) on C -1167 86. Defective D01 (D02), D03, D05 (D04, D06), D07 (D0B) on C-1167 87. Defective TR09 (TR10) on G -1167 Y to G*-63G 4.2. TROUBT

43、ESHOOTING ON THE MECHANICAT SECTION motor Capstan Belt (Drive Belt) FORWARD Switch Lever ( Right) F.F. , L REWIND switch ever(Left) F.F. F. F. Pu lley ( ld ler) spring (Lef t) F.F. Brake Shoe Reel Hub Assy (Lef t) spring ( Rieht) F.F. Brake Shoe Reel Hub Assy ( Rieht) PLAY ldler Assy Capstan (Capsta

44、n Assy whee!) 4-2-1. PLAY I noperative Symptom 1-1 . Capsta n ino perative 1-2. Capstan operative (o rpring, PLAY ldler ld ler, reverse tg. 4-1 Check Point Cau se Motor not rotating Broken drive belt Slippery drive belt and capstan wheel Drive belt slipped off lmproper pressure of pinch-roller to Ca

45、pstan (See Fig. 3-5 on Page 7) S Iippery p i nch ro I ler Weak reel torque Slippery capstan wheel and ldler Weak motor torque due to drop of Power Line Voltage (AC) Slippery idler and right reel hub Weak tongue of spring, PLAY idler (see Fig. 4-2 on page 12) 1. 2. 3. 4. 5. 6. 7. B. 9. 10. ll ,11. G

46、X Capstan whee X Right reel hub X ldler X Drive pulley Fig.4-3 Y v *lf the rotating parts marked* in Fig. 4-3 are slippery Carbon tetrach loride. 4-2-2. FAST TORWARD lnoperative Symptom Check Point 2-1 . No tape movement in FAST FORWARD 4-2-3. REWI N D Inoperative 3-1. No tape movement in REWIND 4-2

47、-4. PAUSE lnoperative (PAUSE does not function mechanically in REWIND mode) 4-1. Returning to STOP mode 4-2-5. lncorrect Tape Speed 4-2-6. Excessive Wow and Flutte or oily, clean the parts by Sansu i head cleaner (SHC-1) or 12. 13. 14. 15. 16. 17. 18. 19. 24. 21. Cause lmperfect contact between FF i

48、d ler and id ler reverse Slippery idler, reverse and right reel hub S Iippery FF belt Brake not released lmperfect contact of FAST FORWARD Sw itc h, S6 lmperfect contact between FF idler and Ieft reel hub Slippery FF id ler and left reel hub Brake not released Slippery FF belt I mperfect co ntact of

49、 REWIN D sw itc h, 57 lmperfect contact of PAUSE sw,itch, 54 Defective motor, MI701 Stretched drive belt Defective capstan lmproper pressure of pinch ro ller to capstan (See Fig. 3-5 on page 7) Change in shape or quality of pinch roller Stretched drive belt Defective cassette tape Oily or slippery reel hub 22. 4. 5. 6. 7. B. 9, 0. 2 2 2 2 2 2 3r Capstan Belt Sprihg, PLAY ldler Fig. 4-2 Y 4-2-7.