background image

SJ-MD100

– 10 –

  Block Diagram

Play signal

*1 Kerr effect

A phenomenon in which the polarization plane of laser light reflected from a material shifts in one of two directions 

 

depending upon its “plus” or “minus” magnetic polarization.

*2 ACIRC 

  Add on interleave CIRC

The aim of Add-on interleave is to improve the resistivity in CD-ROM decoder from the burst error on the disc.

*3 ATRAC 

  Adaptive Transform Acoustic Cording

The digital data compressing system developed for MiniDisc in which audio signals can be reproduced with only about 

th 

1/5   in the data normally required for high fidelity reproduction

*4 Curie temperature

The temperature at which magnetism of a specific material dissipates. This temperature varies according to the material.

*5 UTOC 

  User Table Of Contents

Found only on recordable MiniDiscs, this area contains subdata (track number, etc.) which can be rewritten by the user.

Magnetic
head

Magnetic head
Drive Q10,11

Traverse
motor

Spindle
motor

Optical
pickup

4ch driver IC
IC2   AN8814

    RF    IC
  IC1  AN8772

 MD LSI

IC3   MN66616
   EFM    mod/demo

          ATRAC    encoder /
                            decoder

   Servo signal processor

DRAM(4Mbit)
IC72  MNV4400

Loading motor

Detection SW

Loading drive
IC92  LB1830

    20bit AD /DA converter

  IC601  AK4520

Buffer AMP
IC711   BA4560

Buffer AMP
IC751   BA4560

Head Phone AMP
IC801   M5218

OPTIAL OUT

LINE IN

LINE OUT

H.P. OUT

Interface
IC401 TC74HTC7007

System control
IC901
M30218

FL display

Operation SW

System control
IC10
MN101D03D

Clock
10.02MHz

Clock
16.9334MHz

Clock
10MHz

OPTIAL IN

Interface  IC402
TC74HC4050

Clock
generator
IC501
TC9246

DISC

 

 

REC signal

Clock line

Control line

1        2      24      25

43   44   45   46

73

97

70

69

65

64

71

32

2

3

9

4

8

3

3

5

13

14

0.5

¨

s. 50mV/DIV.

0.45V
P-P

0.5

¨

s. 0.1V/DIV.

0.9V
P-P

0.5

¨

s. 1V/DIV.

3.2V

0V

3.2V

0V

T = 11

¨

s.

. .

0.2

¨

s. 2V/DIV.

3.2V

0V

0.2

¨

s. 2V/DIV.

4.8V

0V

4.8V

0V

T = 0.34

¨

s.

. .

1kHz, 0dB

3.2V
P-P

1kHz, 0dB

6.2V
P-P

1kHz, 0dB

VOLUME CENTER

170mV
P-P

39

38

Summary of Contents for SJ-MD100

Page 1: ...tsushita Electric Industrial Co Ltd All rights reserved Unauthorized copying and distribution is a violation of law ORDER NO AD9903069S2 Colour K Black Type Areas E Europe EB Great Britain EG Germany SJ MD100 Minidisc Deck This document is supplementary to the following Service Manual Supplement for technical information about MD Contents Area Code E EB EG Order No MB9902001C2 Model No SJ MD100 1 ...

Page 2: ...f MD T Definition of an MD and the types of MDs Y MD stands for mini disc Y Similar to a music CD an MD is also a small disc capable of recording and playing back digital sound Y There are 2 types of MDs a optical disc for playback only MD and a magnet optic disc for recordable MD that is capable of both recording and playback Y A playback only MD is merely a smaller diameter version of a CD Just ...

Page 3: ... if a downward facing south north external magnetic field is applied the direction of the magnetism at that location is changed to face downward south north Y Then when the disc rotates and the location which has been changed to upward facing magnetism leaves the laser spot the temperature of the magnetic film drops and the upward facing magnetism recorded at that location is retained Y In this wa...

Page 4: ...o further explain the principle used to read the signals recorded on a magnet optic disc first a laser beam is directed at the disc If the direction of the magnetism recorded on the disc is upward north polarity the plane of polarization of the light reflected from the disc rotates very slightly clockwise as a result of the Kerr effect Conversely if the direction of the magnetism is downward south...

Page 5: ...g recorded is 1 or 0 the direction of the magnetic field also changes between north and south and accordingly the direction of the magnetization of the recording film changes between upward facing and downward facing Thus it is possible to directly magnetize the recording film on the disc in accordance with the 0 and 1 digital signals Y Thus the new recording data is overwritten regardless of the ...

Page 6: ...because the addresses are already recorded around the entire circumference of the disc when the MD is recorded those addresses are read in order to control the movement of the optical pickup and perform CLV control Y To record immediately quick access is first performed to quickly search for an blank area on the disc and then recording will automatically begin When recording is completed that addr...

Page 7: ...best part of the fresh orange is concentrated for easy transportation and then reconstituted with water before drinking Y The basic concept of ATRAC utilizes the characteristics of the human auditory sense The frequency spectrum that cannot be heard by the human ear Fig B and the frequency spectrum that cannot be heard because it is masked by high level sounds Fig C are cut and the bit rate is com...

Page 8: ...e rotation speed so that the servo signal is obtained at a constant linear speed at the location being read Y This is the main signal processing LSI EFM is a circuit which converts 8 bit digital signals into the 14 bit format recorded on the disc It also performs signal processing for error correction changing the interleaving format in order to use the ideal algorithm for MD In addition this LSI ...

Page 9: ...R1 The analog signals input from LINE IN pass through the REC LEVEL VR and are input to pins 5 left channel and 3 right channel of the A D D Aconverter IC601 via the buffer amp IC751 BA4560 input pins 5 left channel and 3 right channel output pins 7 left channel and 1 right channel R2 The analog signals input to the A D D A converter IC601 are converted to digital signals with a sampling frequency...

Page 10: ...a track number etc which can be rewritten by the user Magnetic head Magnetic head Drive Q10 11 Traverse motor Spindle motor Optical pickup 4ch driver IC IC2 AN8814 RF IC IC1 AN8772 MD LSI IC3 MN66616 EFM mod demo ATRAC encoder decoder Servo signalprocessor DRAM 4Mbit IC72 MNV4400 Loading motor Detection SW Loading drive IC92 LB1830 20bit AD DA converter IC601 AK4520 Buffer AMP IC711 BA4560 Buffer ...

Page 11: ...RAM data laser power To ROM RAM Operation page Is CN4 power supply line OK Is oscillation signal output from IC10 pin 33 Check power supply circuit on main unit Faulty IC10 Is IC10 pin 21 H 1 Continued on next page 2 O U S T 5V 5V 5V 3 3V 3 3V CN4 Check reset circuit on main unit NO YES NO YES NO YES NO YES NO YES NO YES NO YES NO YES IC10 pin 33 1 See Srevice Manual page 35 2 See Srevice Manual p...

Page 12: ...nt flowing equal to at least 1 2 times value indicated on pick FPC 2 2 YES NO Is output of IC3 pin 92 OK Is voltage of IC1 pin 2 left side of R8 approx 1 9 V 1 NO YES NO YES NO YES 3 3V 0V 3 3V 0V NO YES NO YES 2 Indicated value Current equal to that on both sides of R5 divided by 1 Faulty IC1 Is voltage of IC9 pin 3 2 6 V YES Faulty L5 Faulty IC9 NO NO Faulty IC3 Faulty IC1 Faulty optical pickup ...

Page 13: ...REC H L H L H 3 3V L 0V 5 NO IC3 pin 21 Faulty IC3 Faulty IC2 Does optical pickup move up and down Continued on next page Does CN4 pin 18 change from H to L when disc is inserted Faulty loading TRG S7 D i s c t r a y O P E N L H H H Is output of IC10 pins 13 15 17 and 18 OK Is voltage of IC10 pins 8 and 9 OK Is voltage output from IC92 pins 2 and 4 Faulty loading motor Faulty S3 S4 S5 and S6 Fault...

Page 14: ... of IC1 pin 11 be adjusted so that it is approx symmetrical with a level of 1 5 Vp p 1 Faulty IC1 or optical pickup Is RF waveform output from IC1 pin 32 TP52 1 Is there output from IC1 pin 29 TP148 or IC3 pin 87 1 IC1 pin 29 TP148 or IC3 pin 87 Is RF signal stable Are communications between IC3 and IC72 OK Communications error Is voltage output from IC3 pin 96 Faulty IC1 Faulty IC1 Faulty IC3 Fau...

Page 15: ... 1 of a previously recorded MD Is playback sound OK Insert a recordable MD Is recording possible Operation complete Faulty magnetic head Faulty magnetic head Is shape of magnetic head OK Is there output from CN8 TP110 and TP111 Is output of IC3 pin 73 OK Faulty magnetic head circuit Faulty IC3 Is output of IC3 pins 61 65 OK during playback 10 9344MHz Faulty audio circuit Faulty IC3 To page 10 Afte...

Page 16: ...emains at outer track Is IC10 pin 12 approx 3 3 V Faulty traverse detection switch S8 Is IC10 pin 12 approx 0 V Faulty shorted traverse detection switch S8 or Is output of IC3 pin 20 OK Is voltage output between IC2 pins 15 and 16 Faulty IC2 Faulty IC3 Faulty traverse motor Printed in Japan F990406500MT KH D ...

Reviews: