Nakamichi pa 300 Schematics

TD-1200 OOD-Sl-3055 (12/13)

(4) PA-300 Power Amplifier

						DID CONVERTER P.C.B.f
POWER AMP P.C.B.I

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AMP P.C.B.I

"Caution''

1.lf a part is in need of removing (or replacing) for service, it should be remounted (or replaced with specified parts) by the same methods as

before after servicing.

2. The appliance should be used only specified parts for preventing a risk of fire and electric shock and maintaining the characteristics.

3.Before returning the repaired appliance to a customer, check to insure that the exposed part is accurately insulated from the Power Supply by measuring the leakage current or the insulation resistance between them.

Fig. 10

Notes: 1. Diode is 1SS53, 1S1555, or 1SS176 unless otherwise specified.

2.Resistor and capacitor marked with *show typical value.

3.2SA733, 2SA608SP, 2SA 1048 and 2SA 1175 are interchangeable with each other.

4.2SC945, 2SC536SP, 2SC2458 and 2SC2785 are interchangeable with each other.

2.Information of Main Modifications after Issue of

Service Manual

Note: Following modifications are already applied for

the Europe version.

2.1. Improvement of FM S/N Ratio

Applied Serial No.: C60103709 -

Modification:

R386 (1 K!l) has been added between the base and emitter (GND) of 0305 on the Tuner P.C.B. Ass'yin

order to improve the FM S/N ratio approx. 5 dB.

Part No.:

Added: R386 OB09667 A Carbon Resistor

			1KS11/6W J
C301		R324	R305
4. 7JJ 25V		3. 9K	·'K
C305 O.Olp IJ l

Q304

2SC945

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R386 Added

Fig. 11 Tuner P.C.B. Ass'y

2.2. Modification of ACC Input Circuit

Applied Serial No.: C60103709 -

Modification:

R635 on the	CPU P.C.B. Ass'y has been changed
from 2.2 K to	1 K. When a car without ACC position

is used, ACC line voltage drops when the starter of the car is activated, resulting in erroneous CPU operation. To prevent this R635 has been changed.

Part No.:

Added: R635 0801857 A Carbon Resistor 1KS11/4W J

Removed: R635 OB05622A Carbon Resistor 2.2KS11/4W J

2.3. Modification of Back Tension

Applied Serial No.: C60103709 -

Modification:

To obtain stronger torque and better wow/flutter characteristics, back tension spring and associated parts have been changed.

Part No.:

New Part No.:

06: OC08445A Reel Hub Cap

37:OC08589A Tension Spring Sleeve

38:OC08467D Back Tension Spring L13: OE03132A Washer 2.1x6x0.25t

Current Part No.:

06: OC08445A Reel Hub Cap

07: OC08467C Back Tension Spring 08: CA08424A Reel Table Ass'y

L03: OE03061A Washer 2.1 mm

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	37
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	New One
		Fig. 13

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Fig. 12 CPU Control P.C.B. Ass'y