Nakamichi CR 4 E Service Manual

Page 1

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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2. REMOVAL PROCEDURES

2.1. Top Covet Auy Ind Bottom Cover Any

Relex to Fig. 2.1.

(1) Loosen F01 and remove F02 (Top Cove: Assy).
(2) Loosen F03 and remove F04 (Bottom Cover Ass'y).

Fix. 2.1

2.2. Cassette can Covet Assy

Rate: {0 Fifi. 2.2.

(1) Press F01 (Elect. Button) kc open F02 (Cassette Case Cover
Ass'y).

(2) Pull F02 (Cassette Case Covu Assy) upward.

H1. 2. 2

2.3. Mechanilm Au'v

Refer to Fifi. 2.3.

(1) Remov: the Top Cover Assy and the Bottom Cover Assy
rennin: to ium 2.1.

(2) Remove the Cassatt: Case Cover Assy refuting to imam 2.2.

(3) Loosen F01. cut F02 with nivvers, remove F03 and F04, and
dunnemble F05 (Mechanism Assy).

2.4. Monitor Switch Joint

Refer to Fix. 2,4.

(1) Remove the Top Cover Assy and the Bonom Cave: Assy
Karen-in: to item 2.1,

(2) With vushinz F01 (Monitor Switch Joint) in the direction of
the mow A, pull F01 (Monitor Swimh Joim.) in the dire anon
of the mow B to remov it.

F33. 2.4

2.5. Front Pmel

Refer to Fig. 2.5.

(1) Remove the Top Covet Assy and the Bottom Cover Assy
reisrdnl ta item 2.1.

(2) Remove the Clssem Case Cover Assy referring to item 2.2.

(3) Pull out F01, F02 and F03. and loosen F04 and F05.

(4) With pushing claws by hand as shown in tha figuze, remove
F06 (Front Panel).