Akai AC 300 Service Manual

Page 2

CONTENTS

[AC-300]
SAFETY INSTRUCTIONS ..
INFORMA110NS
SPECIFICATIONS
I. DISASSEMBLY ........
II. PRINCIPAL PARTS LOCATIONS
III. REPLACEMENT OF PRINCIPAL MECHANICAL PARTS .
IV.ADJUSTMENT .............................................................................................................
V. PARTS LIST .....................

VI.WIRING DIAGRAM ..
VII. BLOCK DIAGRAM ..........................
VIII.SCHEMATIC DIAGRAM ..........
IX. PCB LAYOUT ..................................................
X. INFORMATION OF ICs MI-COM
ABBREVIATIONS ............................................................................................................................................... 53
[SR-300]

I. SPECIFICATIONS ................................................................................ 57
II. SCHEMATIC DIAGRAM ........ 57
III. PARTS LIST ........

Page 10

1-4. REMOVAL OF THE TRAY BLOCK

1)Remove the CD PCB.

2)Slide the GEAR HOLDER RETAINING SCREW in the
direction of the arrow and pull out the TRAY BLOCK
slowly.

3)Remove the CD PCB HOLDER RETAINING SCREWS
then remove the CD PCB HOLDER and the BRACKETS
on both side.

4) Remove the TRAY BLOCK.

GEAR HOLDER RETAINING SCREW

Fig. 1-3

1-5. REPLACEMENT OF THE PICK UP BLOCK

1) Remove the TRAVERSE MECHA.

2) Push the stopper ® in the right direction and pull the
SLIDE SHAFT in the forward direction to remove the
PICK UP BLOCK. then replace the PICK UP BLOCK

3) Reassemble in the reverse order.

PICK UP BLOCK

5@

STOPPER ®
Fig. 1 -5

1-6. REPLACEMENT OF THE SPINDLE MOTOR
Replacement of the SPINDLE MOTOR itself is not. recom-
mended, because the adjustment of the TURN TABLE
height is quite critical and neceositating the use of a special
1'9-

11

Page 53

COMPACT DISC

ABBREVIATION EXPLANATION ABBREVIATION EXPLANATION

A-D Analog to Digital (Converter) Mb ' Mega Bits

ADC Analog to Digital (Converter) MDA Mortor Drive Amplifier

BCD Binary Code Decimal MFM Modified Frequency Modulation
BPI Bits per Inch MM Mono-stable Multivibrator
CD Compact Disc MzFM Modified Modified Frequency Modulation
CIRC Cross Interleaving 8. Reed Solomon Coding M002 Modulo 2(Addition)

CLV Constant Linear Velocity MP Microprocessor

CP Clock Pulses MSB Most Significant Bit

CRCC Cyclic Redundancy Check Codes NA Numerical Aperture

D Level Decision Level NRZ Non Return to Zero

D-A Digital to Analog (Converter) NRZ-1 Non Return to Zero Inverted
DAC Digital to Analog (Converter) P Parity Data

DAD Digital Audio Disc PAM Pulse Amplitude Modulation
DEM Dynamic Element Matching POM Pulse Code Modulation
DPD Differential Phase Detection PD Phase Detector

DSV Digital Sum Value PE Phase Encode

EFM Eight to fourteen Modulation PLL Phase Locked Loop

EX-OR Exclusive OR PNM Pulse Number Modulation
FCI Flux Changes per Inch PPM Pulse Phase Modulation

FIR Finite Impulse Response PWM Pulse Width Modulation

FP Front Pulse Q Parity Data

FPG Front Pulse Gate R, R1, R2, etc Data for Right Channel

F Frequency of Sampling RAM Random Access Memory
GF Galois Field RPG Rear Pulse Gate

H & V (Parity) Horizonai & Vertical SCOOP Self Coupled Optical Pick-up
IIR Infinite impulse Response S 8. H Sample & Hold

KB Kilo Bits S/N Signal to Noise Ratio

L, L, L2, etc Data for Left Channel SSG Standard Signal Gererator
LPF Low Pass Fitter SYSCON SYStem CONtrol

LSB Least Significant Bit