Nakamichi TA 4 A Service Manual

Page 2

CONTENTS

1. General ................................

2. Removal Procedures . .

2. 1. Top Cover Ass y and Bottom Cover Ass y . . .
2. 2. Front Panel Ass y, Remote Control Sensor P. C. B. Ass y and Power Indicator P. C. B. Ass y .
2. 3. Front Chassis Ass y and Control Switch 8: Display P. C B. Ass y .................

2. 4. How to Disconnect/Connect Flat Cable
2. 5. Video & Logic P.C.B. Assy
3. Parts Location for Electrical Adjustment . . .
4. Electrical Adjustments .
4. 1. Power Amplifier Section
4. 2. Tuner Section .......
4.2 1. FM Tuner Section.
AM Tuner Section
5. Mechanism Ass' y and Parts List ......

5. 1. Synthesis ..........
5. 2. Front Panel Assy (A01)
5. 3 Front Chassis Assy (A02) .
5. 4. Chassis Ass'y (A03). . . .
5. 5 Heat Sink Ass y (1301),
6 Mounting Diagrams and Parts List . .

1.

2 Speaker Terminal P. C. B. Ass y
3 Pin Jack P.C.B. Assy ........
4. Headphone Jack P.C.B. Assy . .
5. Power Indicator P.C.B. Assy
6 Volume Indicator P.C.B. Assy
7 Volume Motor P.C.B. Assy .
8. Transistor Joint P.C.B. Assy . . .
9. Remote Control Sensor P.C.B. Assy
10. IF Band Switch P.C.B. Assy ........

12. Remote Jack P.C.B. Assy
Volume P.C.B. Assy . . .
14. Power Supply P.C.B. Assy .
15. Standby P. C. B. Ass y.
16. Tone Control P. C. B. Assy. .
17. Control Switch 8: Display P. C. B. Ass y .
.18. 'TunerPCHBAssy . .
19. Video & Logic P C. B. Ass y . . .
20. Ma1nPCB Ass'
7 . Schematic Diagrams . . . .

7. 1. IC Block Diagrams . . . .

7. 2. Schematic Diagrams . . .
7.2.1. Tuner Section
7.2 2. Video and Control Section . . .
7.2 Amplifier Section ......

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8. Wiring Diagram ..........................
9. Block Diagrams ..........................

9. 1. Tuner Section . .
9. 2. Amplifier Section .....

10. Specifications ...........................

1. GENERAL

1.1. CAUTIONSIWARNINGS
(1) Product Safety Notice

Parts marked with the symbol
gram have critical characteristics.
Use ONLY replacement parts recommended by the
manufacturer.

It is recommended that the unit be operated from a
suitable DC supply or batteries during initial check-out
procedures.

in the schematic dia-

PowerSwitchPCB Ass'y

Selector P.C.B. Assy ............... . I

(2) Leakage Current Check/Resistance Check

Before returning the unit to the customer make sure you
make either (1) a leakage current check or (2) a line to
chassis resistance check If the leakage current exceeds
0. 5 milliamp, or if the resistance from chassis to either
side of the power cord' is less than 240 k ohms, the unit 1s
defective.

WARNING - DO NOT return the unit to the customer
until the problem is located and corrected.