Nakamichi CR 4 A Service Manual

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Nakamichi

Service Manual

Nakamichi
CR-4
CR-4A ,
CR-4E
CR-4O

Discrete Head Cassette Deck

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CONTENTS

1 General ...................................................................... 1
2. Remove! Procedures ............................................................. 3
2. 1. Top Cover Assy and Bottom Cover Assy ....................................... 3
2. 2. Cassette Case Cover ASSy .................................................. 3
2. 3. Mechanism Assy ....................................................... 3
2. 4. Monitor Switch Joint .................................................... 3
2. 5. Front Panel ........................................................... 3
2. 6. Bias P.C.B. Assy and Level Adjustment P.C.B. Assy ................................ 4
2. 7. Control P.C.B. Assy ..................................................... 4
2. 8. Head Mount Base ....................................................... 5
2. 9. Power Switch Joint ...................................................... 5
3. Test Tapes and Gauges ............................................................ 5
4. Mechanical Adjustments .......................................................... 6
4. 1 Record Head and Playback Head Tilt Adjustment .................................. 6
4. 2 Head Base Stroke Check .................................................. 6
4. 3 Erase Head Stroke Adjustment and Tape Guide Height Check .......................... 6
4. 4 Erase Head Height and Tilt Adjustment ........................................ 7
4. 5 Playback Head and Record Head Height Adjustment and Azimuth Alignment ............... 7
4. 6 Tape Travelling Check .................................................... 8
4. 7 Eject Damper Adjustment ................................................. 8
4. 8 Reel Motor Speed Adjustment in Play Mode ..................................... 8
4. 9. Tape Speed Adjustment ................................... 8
4. 10. Lubrication ........................................................... 8
5. Parts Location for Electrical Adjustment ............................ 9
6. Electrical Adjustments ....................................... 10
'I. Mechanism Assy and Parts List ...................................................... 15
7. 1. Synthesis .......................................... 15
7. 2 Chassis Assy (A01) ...................................................... 16
7. 3 Bottom Cover Assy (A02) ................................................. 16
7. 4 Mechanism Assy (301) ................................................... 17
7. 5. Front Escutcheon Assy (BOB) ................................... 17
7. 6. D.D. Motor Ass'y (C01) ................................................... 17
8. Mounting Diagrams and Parts List .............................. 19
B. 1. Fuse P.C.B. Assy ....................................................... 19
8. 2. Pin Jack P.C.B. Assy ............................... 19
8. 3. Input Volume P.C.B. Assy .......................... 19
8. 4. Output Volume P.C.B. Assy ............................................... 20
8. 5. Headphone P.C.B. Assy ................................................... 20
8. 6. Level Adjustment P.C.B. Assy .............................................. 20
8. 7. Bias P.C.B. Assy ....................................................... 20
8. 8. Shut-off P.C.B. Assy

B. 9. Power Supply P.C.B. Assy ..............................................
8. 10. Cal. Osc. P.C.B. Assy ................................................ 21
8, 11. Flywheel Holder Asy ................................................ . . 21
8. 12. Control P.C.B. Assy ..................................................... 24
8. 13. Main P.C.B. Assy ....................................................... 25
9. Schematic Diagrams ............................................................. 29
9. 1. IC Block Diagrams ...................................................... 29
9. 2. Schematic Diagrams .................................................... . 33
10. Wiring Diagram .............................................................. . 35
11. Block Diagrams ...... - 39
11. 1. Amplifier Section ...................................................... . 39
11. 2. Mechanism Control Section ............................................... . 40
12. Timing Charts and Eq. Amp. Frequency Response ........................................ . 40
12. 1. Timing Charts ........................................................ . 40
12. 2. Eq. Amp. Frequency Response ............................................ . 41
18. Specifications ................................................................ . 42

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-----,- ___________________ fl
IoMumaca Assy

Fuse R (2.3.1:sz

Power
TransIormer

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EUROPE (220 V)
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of the P.C.B. is
illustrated unless
otherwise specified.
3. Wire tube color is
shown in ( ).

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I FusePCB Assy I
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I la MainPC a Assy I
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I "-2- Fuse P.C.E, Aséy I
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: VolIage Seleclor I
Notes: 1. Table of wire colors I I
BRN - Brown | I
RED - Red I I
ORN - Orange I In Mam P c a, Ass'y I
YEL - Yellow I I
GRN - Green : I
BLU - Blue I :
VIO - Violet I W Fuse P.C.B, Ass'y I
GRY - Gray I I
WH'X - White I I
BLK - Black I A.c. Inpm PM, I
2. Component side View I Tmnmmm I
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L SAUDI ARABIA (220V) BI OTHER IIIOV/ I27V/220V/240VI

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