Akai GX 620 Service Manual

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STE R E0 TA P E I) EC K

MODEL GX'620

ALSO APPLICABLE TO BLACK PANEL MODEL

SECTION I SERVICE MANUAL .................... 3
SECTION 2 PARTS LIST .......................... 37
SECTION 3 SCHEMATIC DIAGRAM ................ 55

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SECTION I

SERVICE MANUAL

TABLE OF CONTENTS

TECHNICAL DATA .......................................
DISMANTLING OF UNIT ...................................
CONTROLS ............................................

RINCIPAL PARTS LOCATION ..............................

VOLTAGE AND CYCLE CONVERSION .........................

. VOLTAGE CONVERSION ................................
. CYCLE CONVERSION ...................................

VI. CIRCUIT OPERATING PRINCIPLES ...........................

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. CIRCUIT CONSTRUCTION OF [Cl M54410? ...................
. THE SAMPLE AND HOLD SYSTEM
SERVO MOTOR (SCM-ZOO) OPERATION ............

VII. MECHANISM ADJUSTMENT ................................

I
2
3.
4
S

7
8

fi*?§

1
2

. TAPE GUIDE HEIGHT ADJUSTMENT ........................
. REEL TABLE HEIGHT ADJUSTMENT .......................
CAPSTAN SHAFT LOOSE PLAY ADJUSTMENT ................
. IMPEDANCE ROLLER LOOSE PLAY ADJUSTMENT .............
. BRAKE BAND POSITION ADJUSTMENT AND

BRAKE TENSION ADJUSTMENT .................
. PINCH ROLLER PLUNGER INSTALLATION AND

PINCH ROLLER PRESSURE ADJUSTMENT .........
. PAUSE PLUNGER POSITION ADJUSTMENT ...................
. TAPE SPEED ADJUSTMENT ..............................

. HEAD ADJUSTMENT .....................................
AMPLIFIER ADJUSTMENT .................................
DC RESISTANCE OF VARIOUS COILS .........................
CLASSIFICATION OF VARIOUS P.C BOARDS ................. ' . .

. P.C BOARD TITLES AND IDENTIFICATION NUMBERS ...........
. COMPOSITION OF VARIOUS P.C BOARDS ....................

4
5

8
10
[0
ll
12
12
14
l7
I7

19

20
20
21
22
24
27
28
28
29

For basic adjustments, measuring methods, and opera ling principles, refer to GENERAL TECHNICAL
MANUAL