Nakamichi 600 Service Manual

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CONTENTS

1_ General .................................................................... 3
z, Principle of Operation .............. . ............................................. 5
2. 1. p3» Eq. Amp. Circuit ..................................................... 5
2. 2. LM. Suppressm ..................................... 6
2. 3. Unattended Record or Playback, and Shut-off Circuit " 7
2. 3. i. Unattended Record or Playback ------------------------------------------- 7
2_ 3, 2_ Shut-off Circuit ...................................................... 7
3. Removal Procedures . . .' ......................................................... 10
3, 1_ Cabinet .............................................................. 1o

3. 2. Front Panel
3_ 3. Mechanism Assy ............................ ' ....... - ..................... 10
3. 4. Record/Playback Head, Erase Head and Pressure Roller ------------------------------- 10
341.Reoord/PIaybackHead--------------~---'-----------------------~' ..... 10
3A 4, 2_ Erase Head ......................................................... 1o
3_ 4, 3, Pressure Roller ...................................................... 10
72 3_ 5. Cassette Case Assy ........................................... , ............ 1o
3. 6_ Cassette Lid Assy ....................................................... 10
3' 7. Control Button ......................................................... 11
3. 8, Gounter Holder Assy ..................................................... 11
3, 9. Reel Hub Agsy (supply, Take-up) ............................................. 11
3. 10. Motor and Motor Governor Assv --------------------------------------------- 12
3_ 11_ Flywheel ............................................................. 12
, 3, 12_ Idler Pulley ............................................................ 12
3. 13_ From Control ASS'V ................................... A ................... 12
3_ 14_ Main P.C.B, Ass'y ........................................................ 12
3, 15. Dolby p,c,5_ Assy ....................................................... 12
3_ 15, Record Link Assy .................. V. .................................... 11
R 3_ 17' VR p_c.3_ Assy ............. Q ......................................... 12
3_ 13, Meter Assy ............................................................ 12
3. 19. Power Supply P.C_B. Assy .................................................. 12
3_ 20_ Power Switch Ass'y ........................ . . . . ................... 12
4. Measurement and Maintenance Instruments ................... 13
4, 1_ Measurement Instruments .................................................. 13
4. 2. Maintenance instruments ---------------- : ---------------------------------- 13
5. Mechanical Adiustments ......................................................... 15
5. i. Take-up Torque and Rewind Torque Adjustment ----------------------------------- 15
l 5. 2, Tape Speed Adjustment ................................................... 15
5. 3. Record/Playback Head Height Adjustment and Azimuth Alignment ---------------------- 15
5, 4, Head Base Stroke Adjustment ............................................... 15
i 5 5_ Pause Timing Adjustment ............................ ...................... 15
5. 6, Ban Travefling Adiustment ................................................. 16
\ 5_ 7_ Flywheel Adjustment ..................................................... 1e
5, 8, Brake Timing Adjustment .................................................. 16
5. 9. Mute SW. and Start SW. Timing Adjustment ...................................... 17
5. 10. Soienoid Position Adjustment ----------------------------------------------- 17
5_ 11, Record Link Adjustment ................................................... 1B
5_ 12. Lubrication ............................................................ 13
5, 13, Tape Travelling Adjustment ................................................. 19
6. Electrical Adjustments and Measurement ------------------------------------------- 20
6. 'l. Adjustment and Measurement Instructions ------------------------- 57 ------------- 20
6.2. FrequencyfiesponseAdjumem 23
6. 2. 1. Playback Frequency Response Adjustment .................................... 23
6. 2. 2. Record Current Frequency Response Adjustment ................. , .............. 23

7. Part Lmfim for Elam Adjustment .............................................. 24

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5.5. Pause Timing Adjustment
1 This adjustment is required for avoiding the tape spill or
tape skip by the inaccurate pause timing.
See Fig. 5.5.
I (1) Set to the playback mode wimOUt loading the
cassette tape.
1 (2) Depressing the pause button gradually, check to
insure the gap between pressure roller and capstan
\ shaft which will be approximately 0.1mm when
take-up pulley stops rotation because of changing
.. mode from playback to pause. '
(3) In case above is not sufficient, remove the record
link ass'y referring to the item 3.16, record link
assy removal procedure. And adjust the pressure
\ roller as illustrated in the figure.
t
. ITAPE SPILL
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5.6. Belt Travelling Adjustment-
l Refer to the Fig. 5.6 and item 3,10, motor and motor
governor ass'y removal procedure.

\ (1) Adjust the motor pulley position and check to
insure whether the drive belt is travelling along the
. correct position and the staying at the correct
3 position, i.e. the center part of motor pulley and the
idler pulley without contacting the belt guide at the
i following modes:
Playback, FF, REW, FF to Stop. REW to Stop
\ (2) In case motor pulley is tilting, insert spacers into the
A, B (when belt slips upward on the motor pulley)
or C (when belt slips downward). .
\
Hum PULLEV
\ scnaw C 5an AsB 'DLE" PULL
11......

-1. -_ ,

BELT euros
smen Loomons ALB

SPACER

. Fig. 5. 6

5.7. FlywheelAdiustmant

Refer to the Fig. 5.7 and item 3.1, cabinet removal
procedure. Adjust the flywheel clearances should be
0.705 to 0.1 mm. After adjustment lock the lock nut.

Q

THRUST SCREW

LOCK NUT

FLV WHEEL
HOLDER

-0.050.l mm

FLYWHEEL

Fig. 5. 7

5.8. Brake Timing Adjustment

Remove the cassette case referring to the item 3.5, cas-
sette case assy removal procedure.

Refer to the Fig. 5.8.

Loosen screw A, and adiust the contact point between
idler pulley and brake to meet each other when control
button is depressed and mode is changed from FF to
Stop, R EW to Stop and Play to Stop.

Fasten screw A and check to insure the gap between idler
pulley and brake is approximately within 0.2mm.

PROJECTION OF BRAKE

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9. 3. N600 Mechanism Assy (A03)

Fig. 9. 3

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