Nakamichi 480 Service Manual

Page 2

1. General
2. PrincipleofOperation................................

2.

1.

2.1.1.
2.1.2.
2.1.3.
2.1.4.
2.

2.2.1.
2.2.2.

3.

2.3.1.
2.3.2.
2.3.3.
2.3.4.
2.3.5.
2.3.6.
2.3.7.
2.3.8.

Mechanisms............................

.................................................................

.......-...............

......
..............-.......o.......

Headblock.... ....... . .......

EraseHead .. ........ ......

Double Capstan Tape Drive . . . . . .

...............

MechanismControlCircuits.................. . ...... .. .
Outline ...... ........... ..... .

+12VPowerSource ......... ......
Power-mute Signal . . . . ............. . .............. . ......

Auto Shut-off Circuit . . . . ..... . ........ .

......-..............-....

Mechanism Control Cam Operation ...........
Amp.Circuits......... ......
Playback Eq.Amp.Cin:uit .....

Recorqu.Amp.Circuit.............. ....... . ......
2.2.3. BiasOsc.Circult ........ . ........

Record Control Circuit ............... . ....... . . ........ . . ..............

MuteSignal. ..... ..... . ......

Control Motor Drive Circuit . . . . . ...... . . . .

ReelMotorGovernor..... ...... . .........

3. RemovalProoedures ..... . ...... ...

3.
3.

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4. Measurement instruments . . . . . . . .
5. Mechanical Adjustment:

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12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.

1.
2.

95"?

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Cassette Case Cover Ass'y . . ..... . . . . ..... . . . . .

TopCoverks'y ..... ............... . .........

BottomCoverAss'y ...........

FrontPanelAssy....................... ...... . ........

HeadphoneJackAss'y...... ......

MechanismAssy........ .................. ...... ......
MeterAssy ...... ...... ..............
Lamp P.C.B.RAss'y and Lamp P.C.B.LAssy...... . .
Main P.C.B.Assy ...... . ............. . ........ .. ....... .
ControlSwitchHolderAss'y...... .....

Switch P.C.B. Assy . . . ..... . . .............
Volume P.C.B. Ass'y and Control Switch P.C.B. Assy

Rear Panel Ass'y, Power Transformer and Power Switch .

CassetteCaseAssyandCoverFlateAss'y .....
TapeCounterAss'y ...... ........ .....

Capstan Motor Ass'y and Flywheel Ass'y . . . . . . . .

SubMechanismChassisAss'y

Control Motor Assy and Reel Motor Assy . . . . . . .

CamControlVolume.......... ..... . .
ReelHubAssyandldlerAss'y ..................

Cam Drive Gear and Control Cam ..... . ..... . .

... .. .. .

HeadMountBaseAssy ...........

Pressure Roller Ass'y and Erase Head ........ . . .

Record/Playback Head Ass'y . .......... . . . ....... . . . . . . . . . . . . .

Mechanism Control Cam Adjustment . ........ . .
TapeSpeedAdiustment....................

Record/Playback Head Tilt Adjustment ...... . . . . . . . . . . . . . . .

HeadBaseStrokeAdjustment................

.................

. ...... .........

Tape Guides Adjustment and Erase Head Stroke Adjustment . . . . . . . . . . . . .

EreseHead HeightendTiltAdjustment .......... ..

Record/Playback Head Height Adjustment and Azimuth Alignment . . . . . . . . .

TapeTravellingAdjustrnent .....

Record Switch Linkage Adjustment . . . . . . . . . . . . .

...-.....-..............-.................-............----

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Page 22

3.16. Capstan Motor Ass'y and Flywheel Ass'y

Refer to Fig. 3.6.

( 1) Refer to Fig. 3.2. Remove Mechanism Assy referring
to item 3.6.

(2) Remove F01 and F02, then disassemble F03 (Fly-
wheel Holder Assy) and F08 (Capstan Belt).

(3) Remove F04, then disassemble F05 (Capstan Motor
ASS'Y).

(4) Remove F06, then disassemble F07 (Control P.C.B.
Assy).

(5) Remove F09 (Supply Flywheel Ass'y). then dis-
assemble F10 (Take-up Flywheel Ass'y).

(6) After removing both Flywheel Assemblies, disassem~
ble F11 (Thrust Washer 3 mm), F12 (Thrust Washer
2.6 mm), F13 (Flange Thrust Caps) and F14 (Thrust
Springs).

F03

3.17. Sub Mechanism Chassis Ass'y

Refer to Fig. 3.7.»

(1) Refer to Fig. 3.6. Remove Flywheel Assemblies
referring to item 3.15.

(2) Remove F01 and F02, then disassemble F03 (Sub
Mechanism Chassis Assy).

3.18. Control Motor Ass'y and Reel Motor Ass'y

Refer to Fig. 3.7.

(1) Remove Sub Mechanism Chassis Ass'y referring to
item 3.17.

(2) Remove F04, then disassemble F05 (Control Motor
Ass'y).

(3) Remove F06, then disassemble F07 (Reel Motor
Ass'y).

3.19. Cam Control Volume
Refer to Fig. 3.7.
(1) Remove Sub Mechanism Chassis Assy referring to

item 3.17.

(2) Remove F08, then disassemble F09 (Volume Coup-
ler).

(3) Remove F10, then disassemble F11 (Cam Control
Volume).

3.20. Reel Hub Ass'y and Idler Ass'y

Refer to Fig. 3.7.

(1) Remove Sub Mechanism Chassis Ass'y referring to
item 3.17.

(2) Remove F12 (Reel Hub Heads), then disassemble F13
(Reel Hub 8 Assemblies), F14 (Reel Hub Takeup
Assy), F15 (Reel Hub Supply Ass'y), F16 (Back Ten~
sion Ass'y) and F17 (Back Tension Spring).

(3) Remove F18. then disassemble F19 (idler Assy).

3.21. Cam Drive Gear and Control Cam

Refer to Fig. 3.7.

(1) Remove Sub Mechanism Chassis Ass'y referring to
item 3.17.

(2) Remove F20, then disassemble F21 (Cam Drive Gear).

(3) Remove F22, then disassemble F23 (Counter-Load
Arm Assy).

(4) Remove F24, then disassemble F25 (Control Cam).

322. Head Mount Base Assy

Refer to Fig. 3.8.
(1) Refer to Fig. 3.5. Remove Cassette Case Ass'y refer-
ring to item 3.14.

(2) Remove F01, then disassemble F02 (Head Mount
Base Assy).