Sony CMTA-70 Service manual

CMT-A50/A70

SERVICE MANUAL

Ver. 1.1 2005.02

Photo: CMT-A50

US and foreign patents licensed from Dolby Laboratories.

CD CD Mechanism Type FLM-A50
Section Optical Pick-up Block Name KSM-213CCP or KSM-213RCP

Tape deck Model Name Using Similar Mechanism NEW
Section T ape Transport Mechanism T ype CMAL1Z252A

Model Name Using Similar Mechanism NEW

Optical Pick-up Name KSS-213C or KSS-213R

US Model

Canadian Model

Australian Model

CMT-A70

AEP Model

UK Model

CMT-A50/A70

E Model

CMT-A50

AUDIO POWER SPECIFICATIONS
(US model only)

POWER OUTPUT AND TOTAL HARMONIC
DISTORTION
With 6 Ω loads, both channels driven from 100 ­10,000 Hz; rated 55 W per channel-minimum
RMS power, with no more than 10 % total
harmonic distortion in AC operation.

CD player section

System

Compact disc digital audio system

Laser diode properties

Material: GaAlAs
Wave length: 780 nm
Emission duration: Continuous
Laser output: Less than 44.6 µW
(This output is the value measured at a distance of about
200 mm from the objective lens surface on the optical
pick-up block with 7 mm aperture.)

Spindle speed

400 r/min (rpm) to 1 000 r/min (rpm) (CLV)

Number of channels

2

Frequency response

20 - 20 000 Hz +0/–1 dB

Wow and flutter

Below measurable limit

Radio section

Frequency range

FM 87.5 - 108 MHz
AM

US model: 530 - 1 710 kHz
Other models: 531 - 1 611 kHz (9 kHz step)

IF

FM: 10.7 MHz
AM: 450 kHz

530 - 1 610 kHz (10 kHz step)

SPECIFICATIONS

Aerials

FM: Lead aerial
AM: Loop aerial

Cassette-corder section

Recording system

4-track 2 channel stereo

Fast winding time

Approx. 112 s (sec.) with Sony cassette C-60

Frequency response

TYPE I (normal): 50 - 15 000 Hz

General

Speaker

Tweeter: 4 cm dia., 6 Ω (CMT-A50)

2.5 cm dia., 6 Ω (CMT-A70)
Woofer: 13 cm dia., 6 Ω
Passive radiator: 10 cm dia. (CMT-A50 only)

Input

LINE IN jack (stereo minijack)
Minimum input level 430 mV

Outputs

Headphones jack (stereo minijack):

For 8 - 64 Ω impedance headphones
OPTICAL DIGITAL OUT (CD) (optical output
connector):

Wavelength: 630 - 690 nm

Maximum power output

CMT-A50: 20 W
CMT-A70: 60 W

Power requirements

For personal component system:

US model: 120 V AC, 60 Hz

Korean model: 220 V AC, 60 Hz

Other models: 230 V AC, 50 Hz

PERSONAL COMPONENT SYSTEM

For remote control:

3 V DC, 2 R03 (size AAA) batteries

Power consumption

CMT-A50: 50 W
CMT-A70: 100 W

Dimensions

Player:

Approx. 136 × 151.8 × 204 mm (w/h/d)
(incl. projecting parts)

Speaker:

CMT-A50: Approx. 128 × 287 × 215 mm (w/h/d)
(incl. projecting parts)
CMT-A70: Approx. 164 × 267 × 255 mm (w/h/d)
(incl. projecting parts)

Ma

CMT-A50:

Player: Approx. 1.6 kg
Left speaker: Approx. 4.3 kg
Right speaker: Approx. 2.2 kg

CMT-A70:

Player: Approx. 1.6 kg
Left speaker: Approx. 5.6 kg
Right speaker: Approx. 2.9 kg

Supplied accessories

Remote control (1)
FM lead aerial (1)
AM loop aerial (1)
CD-ROM (SonicStage) (1)
SonicStage Installation/Operating Guide (1)

Design and specifications are subject to change without
notice.

9-879-211-02

2005B05-1
© 2005.02

Sony Corporation

Personal Audio Group
Published by Sony Engineering Corporation

CMT-A50/A70

r

SAFETY CHECK-OUT

After correcting the original service problem, perform the following
safety check before releasing the set to the customer:
Check the antenna terminals, metal trim, “metallized” knobs, screws,
and all other exposed metal parts for AC leakage.
Check leakage as described below.

LEAKAGE TEST

The AC leakage from any exposed metal part to earth ground and
from all exposed metal parts to any exposed metal part having a
return to chassis, must not exceed 0.5 mA (500 microamperes.).
Leakage current can be measured by any one of three methods.

1. A commercial leakage tester, such as the Simpson 229 or RCA
WT -540A. Follow the manuf acturers’ instructions to use these
instruments.

2. A battery-operated A C milliammeter. The Data Precision 245
digital multimeter is suitable for this job.

3. Measuring the voltage drop across a resistor by means of a
VOM or battery-operated A C voltmeter . The “limit” indication
is 0.75 V, so analog meters must have an accurate low-v oltage
scale. The Simpson 250 and Sanwa SH-63Trd are examples
of a passive VOM that is suitable. Nearly all battery operated
digital multimeters that have a 2 V AC range are suitable. (See
Fig. A)

To Exposed Metal
Parts on Set

Notes on chip component replacement

• Never reuse a disconnected chip component.

• Notice that the minus side of a tantalum capacitor may be

damaged by heat.

Flexible Circuit Board Repairing

• Keep the temperature of the soldering iron around 270 ˚C
during repairing.

• Do not touch the soldering iron on the same conductor of the
circuit board (within 3 times).

• Be careful not to apply force on the conductor when soldering
or unsoldering.

CAUTION

Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous radiation
exposure.

AC

0.15 µF

1.5 k

Ω

Earth Ground

voltmete
(0.75 V)

Fig. A. Using an AC voltmeter to check AC leakage.

SAFETY-RELATED COMPONENT WARNING!!

COMPONENTS IDENTIFIED BY MARK 0 OR DOTTED LINE
WITH MARK 0 ON THE SCHEMATIC DIAGRAMS AND IN
THE PARTS LIST ARE CRITICAL TO SAFE OPERATION.
REPLACE THESE COMPONENTS WITH SONY PARTS WHOSE
PART NUMBERS APPEAR AS SHOWN IN THIS MANUAL OR
IN SUPPLEMENTS PUBLISHED BY SONY.

ATTENTION AU COMPOSANT AYANT RAPPORT

LES COMPOSANTS IDENTIFIÉS P AR UNE MARQ UE 0 SUR
LES DIAGRAMMES SCHÉMATIQUES ET LA LISTE DES
PIÈCES SONT CRITIQUES POUR LA SÉCURITÉ DE
FONCTIONNEMENT. NE REMPLACER CES COM- POSANTS
QUE PAR DES PIÈCES SONY DONT LES NUMÉROS SONT
DONNÉS DANS CE MANUEL OU D ANS LES SUPPLÉMENTS
PUBLIÉS PAR SONY.

À LA SÉCURITÉ!

UNLEADED SOLDER

Boards requiring use of unleaded solder are printed with the lead­free mark (LF) indicating the solder contains no lead.
(Caution: Some printed circuit boards may not come printed with

the lead free mark due to their particular size)

: LEAD FREE MARK

Unleaded solder has the following characteristics.

• Unleaded solder melts at a temperature about 40 °C higher
than ordinary solder.
Ordinary soldering irons can be used but the iron tip has to be
applied to the solder joint for a slightly longer time.
Soldering irons using a temperature regulator should be set to
about 350 °C.
Caution: The printed pattern (copper foil) may peel away if

the heated tip is applied for too long, so be careful!

• Strong viscosity
Unleaded solder is more viscou-s (sticky, less prone to flow)
than ordinary solder so use caution not to let solder bridges
occur such as on IC pins, etc.

• Usable with ordinary solder
It is best to use only unleaded solder but unleaded solder may
also be added to ordinary solder.

2

TABLE OF CONTENTS

CMT-A50/A70

1. SERVICING NOTES ............................................... 4

2. GENERAL ................................................................... 6

3. DISASSEMBLY

3-1. Disassembly Flow ........................................................... 9

3-2. Cabinet Rear .................................................................... 10

3-3. CD Door .......................................................................... 10

3-4. CD Mechanism Deck (FLM-A50) .................................. 11

3-5. SUB Board ...................................................................... 11

3-6. Top Case Assy ................................................................. 12

3-7. MAIN Board.................................................................... 12

3-8. CD Board......................................................................... 13

3-9. Tray.................................................................................. 13

3-10. Optical Pick-up Block

(KSM-213CCP or KSM-213RCP) .................................. 14

3-11. Optical Pick-up (KSS-213C)........................................... 14

3-12. Optical Pick-up (KSS-213R)........................................... 15

3-13. Tape Mechanism Deck (CMAL1Z252A)........................ 15

4. TEST MODE.............................................................. 16

5. ELECTRICAL ADJUSTMENTS

Deck Section.................................................................... 18

CD Section ...................................................................... 19

6. DIAGRAMS

6-1. Block Diagram – SERVO Section –............................... 20

6-2. Block Diagram – MAIN Section –................................. 21

6-3. Block Diagram

– PANEL, POWER SUPPLY Section – .......................... 22

6-4. Printed Wiring Board – CD Board – .............................. 24

6-5. Schematic Diagram – CD Board – ................................. 25

6-6. Printed Wiring Board

– MAIN Board (Component Side) – ............................... 26

6-7. Printed Wiring Board

– MAIN Board (Conductor Side) – ................................. 27

6-8. Schematic Diagram – MAIN Board (1/2) – ................... 28

6-9. Schematic Diagram – MAIN Board (2/2) – ................... 29

6-10. Printed Wiring Board – SUB Board – ............................ 30

6-11. Schematic Diagram – SUB Board – ............................... 31

6-12. Printed Wiring Boards – PANEL, MOTOR Section – ... 32

6-13. Schematic Diagram – PANEL, MOTOR Section –........ 33

6-14. Printed Wiring Boards

– AMP, POWER SUPPLY Section (CMT-A50 only) – .. 34
6-15. Schematic Diagram

– AMP, POWER SUPPLY Section (CMT-A50 only) – .. 35
6-16. Printed Wiring Boards

– AMP Section (CMT-A70 only) – ................................. 36

6-17. Schematic Diagram

– AMP Section (CMT-A70 only) – ................................. 37

6-18. Printed Wiring Board

– POWER SUPPLY Section (CMT-A70 only) – ............ 38

6-19. Schematic Diagram

– POWER SUPPLY Section (CMT-A70 only) – ............ 39

7. EXPLODED VIEWS

7-1. Overall Section ................................................................ 50

7-2. Front Panel Section ......................................................... 51

7-3. Top Case Section ............................................................. 52

7-4. CD Mechanism Deck Section (FLM-A50) ..................... 53

7-5. Optical Pick-up Section (KSM-213CCP)........................ 54

7-6. Optical Pick-up Section (KSM-213RCP)........................ 55

7-7. Speaker (Left) Section (A50) .......................................... 56

7-8. Speaker (Right) Section (A50) ........................................ 57

7-9. Speaker (Left) Section (A70) .......................................... 58

7-10. Speaker (Right) Section (A70) ........................................ 59

8. ELECTRICAL PARTS LIST................................ 60

3

CMT-A50/A70

Ver. 1.1

SECTION 1

SERVICING NOTES

NOTES ON HANDLING THE OPTICAL PICK-UP
BLOCK OR BASE UNIT

The laser diode in the optical pick-up block may suffer electrostatic
break-down because of the potential difference generated by the
charged electrostatic load, etc. on clothing and the human body.
During repair, pay attention to electrostatic break-down and also
use the procedure in the printed matter which is included in the
repair parts.
The flexible board is easily damaged and should be handled with
care.

NOTES ON LASER DIODE EMISSION CHECK

The laser beam on this model is concentrated so as to be focused on
the disc reflective surface by the objective lens in the optical pick­up block. Therefore, when checking the laser diode emission,
observe from more than 30 cm away from the objective lens.

LASER DIODE AND FOCUS SEARCH OPERATION
CHECK

Carry out the “S curve check” in “CD section adjustment” and check
that the S curve waveforms is output three times.

• MODEL IDENTIFICATION

– Left Speaker Back Panel –

Model Destination

AEP, UK, Italian,

CMT-A50

CMT-A70

East European
and Russian models
Korean model AC: 220V-60Hz 50W
US and Canadian model AC: 120V 60Hz 100W
AEP, UK, Italian,
East European, Russian AC: 230V-50Hz 100W
and Australian models

Power requirements
indication

Power Requirements

Indication

AC: 230V-50Hz 50W

HOW TO OPEN THE CD TRAY WHEN POWER SWITCH TURNS OFF.

2

Pull-out the CD tray.

1

Using a flat-tip screwdriver of the diameter
less than 4 mm, rotate the gear in the arrow
direction.

4

CMT-A50/A70

Adjusting the contrast
of the display

Jog dial (PUSH
ENTER/
MEMORY)

1

Press DISPLAY when the player is
turned off.

The MENU display appears.

2

Press the jog dial or + to select
“CONTRAST”.

The contrast digits (1 - 32) flash on the
display.

+

DISPLAY

Changing the resume
play setting

The player is initially set to start playback
from the point you last stopped playing
(resume play)

You can cancel resume play and the player
always will start from the first track.

(PUSH ENTER/
Jog dial

MEMORY)

1

Press DISPLAY when the player is
turned off.

2

Turn the jog dial to select “CD
RESUME OFF”.
“OFF” flashes on the display.

DISPLAY

3

Turn the jog dial to select the number
for the contrast you want while
observing the display.

4

Press the jog dial to enter the selection.

3

Press the jog dial to enter the selection.
To go back to the clock display, press

the jog dial again.

To reset the resume play
function

In step 2 above turn the jog dial until “CD
RESUME ON” appears and then press the
jog dial twice.

5

CMT-A50/A70

appears on the display.

Basic Operations

Playing a CD

1, 2

SECTION 2

GENERAL

This section is extracted from
instruction manual.

3 Press CD u (u on the remote).

3

The player plays all the tracks once.

Display
Audio CD

Track name*

* When playing an audio CD

containing text information
such as CD-TEXT, track name

ATRAC CD/MP3 CD**

Playing timeTrack number Playing time

File name

File number

**When playing an MP3 CD,

“MP3” appears on the display.

Basic

Operations

For hookup instructions.

1 Press Z OPEN/CLOSE (direct

2 Press Z OPEN/CLOSE to close the

GB

6

Playing a CD

Notes

• If A TRA C3plus/ATRAC3
files and MP3 files are
recorded on the same CD,
this CD player plays the
ATRAC3plus/ATRAC3
only.

• The playback capability of
this CD player may vary
depending on the quality of
the disc and the condition of
the recording device.

• Characters that can be
displayed on this CD player
are listed below.
–A to Z
–a to z
–0 to 9
–! " # $ % & ' ( ) * + , - . / :

; < = > ? @ [ \ ] ^ _ ` { | }

~
If you use other characters
on your computer using
software such as
SonicStage, they are
displayed as “–” on this CD
player.

• On a disc that has
ATRAC3plus/ATRAC3/
MP3 files, do not save files
in other formats and do not
make unnecessary groups.

power-on) and place the CD on the
CD tray.

CD tray.

(continued)

To Press

select a group*3 + to go forward and – to go

select a file*

remove the CD Z OPEN/CLOSE*
turn on/off the player ?/1
*

*

The structure of ATRAC CDs/MP3 CDs

ATRAC CDs/MP3 CDs consist of “files” and “groups.” A
“file” is equivalent to a “track” of an audio CD. A “group”
is a bundle of files and is equivalent to an “album.”
For MP3 CDs, this CD player recognizes an MP3 folder as
a “group” so that ATRAC CDs and MP3 CDs can be
operated in the same way.

Playing order of ATRAC CDs and MP3 CDs

For ATRAC CDs, files are played in the order selected in
SonicStage.
For MP3 CDs, the playing order may differ depending on
the method used to record MP3 files on the disc. In the
following example, files are played in order of 1 to 7.

3

3

You can operate during play of ATRAC CDs/MP3 CDs.

4

Once you open the CD tray, the track to start play will change to
the beginning of the first track.

Group
File

ATRAC CD

With the label side up

backward
M/> to go forward and ./m to

go backward

4

MP3 CD

Note

Before playing an ATRAC
CD/MP3 CD, this player
reads all file and group
information on the CD.
Depending on the file
structure, it may take more
than a minute to read them.
During this time, “Reading”
is displayed.

Tips

•To listen through
headphones, connect the
headphones to the i
(headphones) jack.

• Playback starts from the
point you last stopped
playing (Resume play).
During stop, the point to be
played is displayed.
To start play from the
beginning of the first track,
press STOP x in stop
mode.
To cancel the resume play.

Use these buttons for additional operations

?/1
CD u

–, +

STOP x

VOLUME

M/>

./m

Z OPEN/CLOSE

To Do this

adjust the volume Turn the VOLUME control. (Press

stop playback Press STOP x (x on the remote).
pause playback Press CD u*2 (u on the remote).

go to the next track Press M/>.
go back to the Press ./m.

previous track

1

The button has a tactile dot.

*

2

*

There is a tactile dot beside CD u on the main unit.

Notes on ATRAC CDs

• Maximum number of groups: 255
Maximum number of files: 999

• CD-Rs/CD-RWs recorded in the ATRAC3plus/ATRAC3 format
cannot be played on your computer.

Notes on MP3 CDs

• Maximum number of groups: 100
Maximum number of files: 400
Maximum directory level: 8

•A group that does not include an MP3 file is skipped.

• Be sure to add the file extension “mp3” to the file name.
However, if you add the file extension “mp3” to a file other than
an MP3 file, the player will not be able to recognize the file
properly.

• This player can play bit rates of 16 to 320 kbps, and sampling
frequencies of 32/44.1/ 48 kHz. Variable Bit Rate (VBR) file
can also be played.

•To compress a source in an MP3 file, we recommend setting the
compression parameters to “44.1 kHz,” “128 kbps,” and
“Constant Bit Rate.”

•To record up to the maximum capacity, set the writing software
to “halting of writing.”

•To record to the maximum capacity at one time up on media that

has nothing recorded on it, set the writing software to “Disc at

Once.”

1

, – on the remote.)

VOL +*

The playing time of the current track/file
flashes on the display.
Press the button again to resume play after
pause.

continued

GB

7

Basic

Operations

GB

8

GB

9

6

CMT-A50/A70

Listening to the radio

1 2

For hookup instructions.

1 Press TUNER BAND•AUTO

2 Press TUNING + or TUNING – and

PRESET (BAND on the remote)
repeatedly until the band you want
appears on the display (direct power­on).

hold it until the frequency digits
begin to change on the display.

The player automatically scans the
radio frequencies and stops when it
finds a clear station.

If you cannot tune in a station, press
TUNING + or TUNING – repeatedly
to change the frequency step by step.

Display

Indicates an FM
stereo broadcast

Tips

• If the FM broadcast is
noisy, press MODE/DIR
(MODE on the remote)
repeatedly until “Mono”
appears on the display and
radio will play in monaural.

• If you need to change the
AM tuning interval.

•When you tune in an FM
station that provides RDS
(Radio Data System)
services, “R•D•S” and the
name of the station appear
on the display (European
model only). For details.

Use these buttons for additional operations

?/1

VOLUME

MODE/DIR

To Do this

adjust the volume Turn the VOLUME control. (Press

turn on/off the radio Press ?/1.
* The button has a tactile dot.

To improve broadcast reception
FM

Keep the FM lead aerial as horizontal as possible and
reorient it.

AM

Keep the AM loop aerial away as far as possible from the
player and reorient it.

VOL +*, – on the remote.)

Basic

Operations

GB

10

Playing a tape

For hookup instructions.

1 Press Z PUSH OPEN/CLOSE to

2 Press Z PUSH OPEN/CLOSE to

3 Press TAPE Y (Y on the

open the tape compartment and insert
a recorded tape. Use TYPE I
(normal) tape only .

close the compartment.

remote).
The player turns on (direct power-on)

and starts playing.

1, 2 3

With the side you want

to play facing up

Display

Use these buttons for additional operations

?/1

Z

PUSH OPEN/

CLOSE
TAPE Y

STOP x

VOLUME

./m, M/>

MODE/DIR

To Do this

adjust the volume Turn the VOLUME control.

stop playback Press STOP x (x on the remote).
play the reverse side Press TAPE Y (Y on the remote).
fast-forward or rewind Press M/> or ./m.

the tape
eject the cassette Press Z PUSH OPEN/CLOSE.
turn on/off the player Press ?/1.
* The button has a tactile dot.

To select the direction mode of the tape

Press MODE/DIR repeatedly (MODE on the remote).

To p l a y Display shows

one side of the tape g
both sides of the tape h

from the upper side to reverse
side

both sides of the tape repeatedly j

(Press VOL +*, – on the remote.)

GB

11

Basic

Operations

GB

12

GB

13

7

CMT-A50/A70

The Timer

Setting the clock

“– –:– –” indicator appears on the display
until you set the clock.

Jog dial
(PUSH ENTER/
MEMORY)

CLOCK

Note

If you disconnect the AC power cord, the clock
display may return to “– –:– –”. In this case set the
clock again.

Tip

The time display system of this player is the 12­hour system.
AM 12:00 = midnight
PM 12:00 = noon

To check the present time

Press CLOCK to display the clock, and press
it again to go back to the previous display.

Before you begin, hook up the system.

1

Press and hold CLOCK until the hour
digit flashes.

2

Set the clock.

1 Turn the jog dial to set the hour and

press it.

2 Turn the jog dial to set the minutes.

3

Press the jog dial.
The clock starts from 00 seconds.

30

8

• This set can be disassembled in the order shown below.

3-1. DISASSEMBLY FLOW

CMT-A50/A70

SECTION 3

DISASSEMBLY

SET

3-2. CABINET REAR

(Page 10)

3-5. SUB BOARD

(Page 11)

3-6. TOP CASE

ASSY
(Page 12)

Note 1: The process described in can be performed in any order.
Note 2: Without completing the process described in , the next process can not be performed.

3-3. CD DOOR

(Page 10)

3-4. CD MECHANISM DECK

(FLM-A50)
(Page 11)

3-8. CD BOARD

(Page 13)

3-10. OPTICAL PICK-UP BLOCK

(KSM-213CCP or KSM-213RCP)
(Page 14)

3-11. OPTICAL PICK-UP

(KSS-213C)
(Page 14)

3-9. TRAY

(Page 13)

3-12. OPTICAL PICK-UP

(KSS-213R)
(Page 15)

3-7. MAIN BOARD

(Page 12)

3-13. TAPE MECHANISM DECK

(CMAL1Z252A)
(Page 15)

9

CMT-A50/A70

)

Ver. 1.1

Note: Follow the disassembly procedure in the numerical order given.

3-2. CABINET REAR

6

two screws

5

two stickets

1

five screws
(BVTP3

4

cabinet rear

×

10

3-3. CD DOOR

4

CD door

2

4

two screws

3

two stickets

gear

2

two screws
(BVTP3

×

10)

10

3

three claws

1

Using a flat-tip screwdriver of the diameter
less than 4 mm, rotate the gear in the arrow
direction.

3-4. CD MECHANISM DECK

)

(FLM-A50)

2

connector
(CN306)

2

connector
(CN310)

4

CD mechanism deck (FLM-A50)

1

flexible flat cable (29 core
(CN702)

CMT-A50/A70

3-5. SUB BOARD

3

two screws
(BVTP3

1

screw (B2.6)

2

harness

3

×

10)

connector
(CN309)

4

SUB board

11

CMT-A50/A70

)

3-6. TOP CASE ASSY

2

connector
(CNP304)

3

boss

4

top case assy

1

flexible flat cable (8 core)
(CN303)

2

connector
(CN302)

3

boss

3-7. MAIN BOARD

3

claw

2

connector
(CN306)

3

claw

2

connector
(CN310)

2

connector
(CN311)

4

MAIN board

1

flexible flat cable
(29 core) (CNF307

12

1

flexible flat cable
(25 core) (CN305)

3-8. CD BOARD

d

4

wire (flat type)
(16 core) (CN701)

5

CMT-A50/A70

CD boar

3-9. TRAY

6

tray

1

Remove four
solders.

1

two screws
(P2.6

gear

3

×

8)

2

chuck plate assy

2

screw

4

3

Rotate the gear
in the direction of arrow.

5

two claws

13

CMT-A50/A70

)

Ver. 1.1

3-10. OPTICAL PICK-UP BLOCK

(KSM-213CCP or KSM-213RCP)

5

two bosses

6

arm

7

vibration proof
rubber (green)

4

two screws
(PWH2.6

2

screw
(PWH2.6

×

×

10)

10)

8

vibration proof
rubber (red)

1

two screws
(PWH2.6

×

10)

8

vibration proof
rubber (red)

9

optical pick-up block
(KSM-213CCP or KSM-213RCP

7

vibration proof
rubber (green)

3

drive gear

3-11. OPTICAL PICK-UP

(KSS-213C)

4

optical pick-up (KSS-213C)

1

gear (A)

2

gear (B) (RP)

14

3

sled shaft

3-12. OPTICAL PICK-UP (KSS-213R)

t

1

2

two screws (M2)

gear (B)

3

5

optical pick-up
(KSS-213R)

4

sled shaf

CMT-A50/A70

3-13. TAPE MECHANISM DECK

(CMAL1Z252A)

6

tape mechanism deck (CMAL1Z252A)

5

head shield

2

Open the top case.

3

two screws

4

(PTT2.6

1

four screws

×

×

6)

(BVTP3

10)

15

CMT-A50/A70

SECTION 4

TEST MODE

CD TEST MODE

1. Entering The CD Test Mode

Procedure:

1. Press the [POWER] button to turn the power on, and
[FUNCTION] button to select the CD function.

2. Load a disc for test.

3. Press the three buttons of x , [MODE/DIR] and [CLOCK]
simultaneously.

4. Enter the CD Test Mode and display “88” on the LCD.

5. In the CD Test Mode, it changes mode as following figure.

6. In the mode of except FOCUS2 mode, press the ./m
or M/> button to move the sled motor.

CD Test Mode flow:

( ) number: display number

RW MODE

(RW)

STOP3 MODE

(83)

x

FOCUS2 MODE

(FC)

[DISPLAY]

AUTO MODE

(A-)

automatic

transition

[DISPLAY]

CD u

FOCUS1 MODE

ALL SERVO MODE

CD u

CD u

[DISPLAY]

CD u

[DISPLAY]

(F-)

CD u

(P-)

CD u

x

INITIAL MODE

(88)

x

STOP1 MODE

(81)

x

STOP2 MODE

(82)

x

x

2. Releasing The CD Test Mode

To release this mode, press the [DISPLAY] button for to seconds in
the mode of STOP1, STOP2 or STOP3. Or disconnect the A C plug.

(Not used in servicing)

[MODE]

[MODE]

x

E-F ADJ1 MODE

(E1)

x

FG/TG ADJ1 MODE

(E2)

x

F.B ADJ1 MODE

(E3)

x

RF AVE MODE

(E4)

x

FE/TE AVE MODE

(E5)

x

RFDC PK1 MODE

(E6)

x

RFDC PK2 MODE

(E7)

x

FZC MON MODE

(E8)

[MODE]

[MODE]

[MODE]

[MODE]

[MODE]

[MODE]

[MODE]

[MODE]

CD u

CD u

CD u

CD u

CD u

CD u

CD u

CD u

16

T. G UP MODE

(P- GUP)

x

CD u

CD u

CD u

[MODE]

E-F ADJ2 MODE

(P1)

or

(F1)

[MODE]

FG/TG ADJ2 MODE

(P2)

or

(F2)

[MODE]

F.B ADJ2 MODE

(P3)

or

(F3)

[MODE]

x

FCS PRM MODE

(10)

CD u

[MODE]

x

TRK PRM MODE

(20)

CD u

[MODE]

x

SLD PRM MODE

(30)

x

x

x

x

CLV PRM MODE

x

DFT PRM MODE

x

MON PRM MODE

[MODE]

(40)

[MODE]

(50)

[MODE]

(60)

CD u

CD u

CD u

CD u

[MODE]

DISPLAY TEST MODE

Procedure:

1. Press the [POWER] button to turn the power on.

2. Press the three buttons of x , [MODE/DIR] and [TIMER]
simultaneously.

3. Enter the Display Test Mode and display the version of
microcomputer (IC309 on the MAIN board) for 10 seconds.

4. Then lights up the all segments and all off alternately ev ery 10
seconds.

5. To release this mode, press the [DISPLAY] button for 2 seconds.

CMT-A50/A70

17

CMT-A50/A70

– MAIN BOARD (Component Side) –

RV201

RV101

)

SECTION 5

ELECTRICAL ADJUSTMENTS

DECK SECTION

0 dB = 0.775 V

• Precaution

1. The adjustment should be performed with the rated power
supply voltage.

2. The adjustments should be performed for both L-ch and R-ch.

REC BIAS ADJUSTMENT

Procedure:

1. Record mode

MAIN board
LINE IN jack (J301)

1) 315 Hz

2) 10 kHz

AF OSC

attenuator

2. Mode: Playback

recorded
portion



50 mV (–23.8 dB)




600

set

blank tape

Ω

set

level meter

CN-123

+
–

Adjustment Location:

SUB board
CN312 (pin

(pin

4

: L-CH)

3

: R-CH

3. Confirm playback the signal recorded in step 1 become
adjustment level as follows.

4. If these levels do not adjustment le vel, adjustment the RV101
(L-ch) and RV201 (R-ch) to repeat steps 1 and 4.

Adjustment level: Playback output of 315 Hz to playback output

of 10 kHz: 0 ± 1.0 dB (0 ± 4.5mV).

– SUB BOARD (Conductor Side) –

1516

CN312

1

2

18

CMT-A50/A70

e

e

CD SECTION

Note:

1. Perform all CD section check in the CD Test Mode.
(Refer to page 16)

2. Use the PATD-012 disc (Part No.: 4-225-203-01).

3. Use an oscilloscope with more than 10 MΩ impedance.

4. Clean the object lens by an applicator with neutral detergent when the
signal level is low than specified value with the following checks.

TRAVERSE CHECK

oscilloscop

(DC range)

CD board

TP (TE)
TP (VC)

Procedure:

1. Connect an oscilloscope to TP (TE) and TP (VC) on the CD
board.

2. Load the disc (PATD-012).

3. Press the three buttons of x , [MODE/DIR] and [CLOCK]
simultaneously to enter the CD Test Mode and display “88”
(Initial mode).

4. Press the CD u button to enter the FOCUS1 mode and
display “F-”.

5. Confirm that the center level of waveform is 0 V.

6. Confirm that the Vp-p value of waveform is 0.35 to 1.1 V.

+
–

Checking Location:

– CD Board (Conductor Side) –

TP

(VC)

TP

(TE)

TP

(RF)

IC702

VOLT/DIV: 0.2 V (with the 10:1 probe in use)
TIME/DIV: 1 ms

0 V

Vp-p

FOCUS BIAS CHECK

oscilloscop

(AC range)

CD board

TP (RF)
TP (VC)

Procedure:

1. Connect an oscilloscope to TP (RF) and TP (VC) on the CD
board.

2. In the FOCUS1 mode, press the CD u button to enter the
ALL SERVO mode and display “P-”.

3. Confirm that the oscilloscope waveform is as shown in the
below figure. (eye pattern)
A good eye pattern means that the diamond shape “◊” in the
center of the waveform can be clearly distinguished.

VOLT/DIV: 0.2 V (with the 10: 1 probe in use.)
TIME/DIV: 200 ns

+
–

CMT-A50/A70

0.6 to 1.2 Vp-p

When observing the eye pattern, set the oscilloscope
for AC range and raise vertical sensitivity.

1919

CMT-A50/A70

SECTION 6

DIAGRAMS

6-1. BLOCK DIAGRAM – SERVO Section –

OPTICAL PICK-UP

BLOCK

(KSS-213C)

VC

16

VCC

15

A

12

B

11

C

10

D

13

E

14

F

9

LD

GND

PD

VR

F+

FOCUS

COIL

F-

COIL

M701

(SLED)

M702

T+

T-

M

M

TRACKING

(SPINDLE)

CD +3.3V

AUTOMATIC

POWER CONTROL

Q701, 702

RF AMP, FOCUS/TRACKING

ERROR AMP

IC701

RF AC

VC

27

A

6

B

7

C

8

D

9

E

10

F

11

LD

1

PD

2

COIL/MOTOR DRIVE

F+

13

F–

12

T+

2

T–

1

SL+

16

SL–

17

SP+

26

SP–

27

IC704

RFDC

RFDCI

SW

FFDR

FRDR

TFDR

TRDR

SFDR

SRDR

SPIN

MUTE

15

28

29

FE

16

FEI

17

TE

18

12

10

20

19

24

15

CD DSP

IC702

RFAC

84

88

92

90

91

D-RAM

IC705

4

2

.

.

D0
D3

A0

A10

XWE
XCAS
XRAS

9

5

4

3

3

.

.

6

22

.

.

5

23

116

8

113

.

11

.

17

14

15

.

19

.

13

7

11

.

117

4

2

21

9

5

1

96

95

98

97

100

99

103

RFDC

FE

TE

SE

D0
D3

A0

A10

XWE
XCAS
XRAS

FFDR

FRDR

TFDR

TRDR

SFDR

SRDR

MDP

AOUT1

AOUT2

DOUT

PCMDI

BCKI

LRCKI

PCMD

BCK

LRCK

XRDE

XTAI

XTAO

SSTP

DATA

CLOK

XLAT

XSOE

SCOR

SENS

FOK

GFS/MNT2/

XROF

XRST

51

56

62

109

111

107

108

110

106

18

16.9344MHz

47

48

101

21

20

23

24
27

22

65

69

28

R-CH

X701

S701

(LIMIT)

X702

22.58MHz

MP3 DECODER

PCMDO

15

BCKO

13

LRCKO

14

PCMDI

4

BCKI

2

LRCKI

1

XRDE

12

XTAL

30

EXTAL

29

IC703

SDOUT

SDIN

SDCLKI

RDENO

XWAKEI

NRSTI

J302

OPTICAL

1

DIGITAL

OUT (CD)

40

41

38

42SDXLATI

37

34

33

CD-L

A

58

59

60

10

52

13

12

19

20

21

8

47

18

1

2

3

9

(Page 21)

CD_SDIN

CD_SDOUT

CD_SDCK

CD_SDXLAT

CD_RDEN

CD_XWAKE

CD_NRST

CD_DATA (O)

CD_CLK (O)

CD_XLAT

CD_XSOE

CD_SCOR

CD_SENS

CD_FOK

CD_GFS

SYSTEM CONTROLLER

CD_XRST

CD_LDON

IC309 (1/3)

CMT-A50/A70

R-ch is omitted due to same as L-ch.

SIGNAL PATH

: CD PLAY (ANALOG OUT)

: CD PLAY (DIGITAL OUT)

CD_PWM RF

5

CD_PWM FE

7

CD_RW/ROM

4

CD_PWM TE

6

M651

(LOADING)

MM

S651

TRAY OPEN/CLOSE

()

DETECT

LOADING MOTOR

DRIVE
IC651

OPEN

CLOSE

CD_OPEN

16

CD_CLOSE

15

CD_OPENIN

17

CD_CLOSEIN

14

2020

6-2. BLOCK DIAGRAM – MAIN Section –

CMT-A50/A70

FM 75Ω

COAXIAL

AM

FM ANT

AM ANT

FM/AM

TUNER PACK

+9V

RDS+3.3V

L-CH

R-CH

ST DOUT

ST DIN

ST CLK

ST CE

ST MUTE

STEREO

TUNED (O)

RDS DATA

RDS INT

(Page 20)

TU +9V
RDS +3.3V

RDS DATA

RDS INT

(AEP, UK, EE, RU)

CD-L

A

R-CH

ST DO

ST DI

ST CLK

ST CE

ST MUTE

STEREO

TUNED

J301

LINE IN

MUTING

Q102

MUTING
CONTROL
Q323, 324

R-CH

11

TAPE IN L

R-CH

PB OUT L

J751

i

SP501

SP502

B

MUTING

Q103

MUTING
CONTROL
Q303, 305

HEADPHONE AMP

IC303

R-CH

IC501 (CMT-A50)
IC501 (CMT-A70)

POWER AMP

STANDBY

SWITCH

Q506

IC502 (CMT-A50)
IC502 (CMT-A70)

MUTING

Q101

R-CH

R-CH

OVER LOAD

DETECT

Q507

+

PROTECT

SWITCH

Q509

PROTECT
CONTROL

R-CH

R-CH

R-CH

+

PROTECT

P-ON MUT

• R-ch is omitted due to same as L-ch.

• SIGNAL PATH
: TUNER : TAPE PLAY

: CD PLAY

: TAPE REC

: LINE IN

INPUT SELECT,

ERECTRICAL VOLUME

IC301

MD IN L

59

CD IN L

63

61

7

3

TU IN L

TAPE L

TONE OUT L

REC OUT L

15

37

36

SI19SC

18

VOL IN L

VOL OUT L

33

MUTING

Q501, 510

R-CH

MUTING
CONTROL
Q503, 504

(Page 22)

HRPE301

(REC/PB/ERASE)

L-CH

R-CH R-CH

RV101

REC BIAS

(L)

ERASE

TAPE MECHANISM

DECK BLOCK

R-CH

ISS

Q334

TRGM+

PACK
F REC
R REC

PLAY SW

END SW

BIAS OSC

T301

BIAS OSC

Q307, 308

TRIGGER PLUNGER

REC/PB

SWITCH

IC302

DRIVE

Q314, 315

LEVEL SHIFT

Q302, 304

REC BIAS

SWITCH

Q310, 311, 313

74

72
70
71
69
73

A +9V

T-SOL

T-CASS
T-A
T-B
T-PWS
T-REEL

STBY

C

(Page 22)

ST DI

ST CE

ST DO

ST CLK

28

55

92

67

68

ISS2

T-PR

T-BASS

57

RA-CLK

RA-DAT (I)

R-DATA (O)

56

ST MUTE

76

RA-CE

ST-MUTE

TUNED

STEREO

61

62

RA-ST

R-SD (TUNED)

(AEP, UK, EE, RU)

RDS INT

RDS DATA

27

29

RDS-INT (I)

RDS-DATA (IN)

31

CD-MUTE

36

33

AU_A_SDA

AU_A_SCL

SYSTEM CONTROLLER

IC309 (2/3)

32

A-MUTE

66

HP-MUTE

48

PSTBY

87

PROTECT

65

HP-SW

CMT-A50/A70

2121

CMT-A50/A70

6-3. BLOCK DIAGRAM – PANEL, POWER SUPPLY Section –

SYSTEM CONTROLLER

IC309 (3/3)

LCD_AD0 - LCD_AD7

93 – 100

LIQUID CRYSTAL

D702, 703

(LCD BACK LIGHT)

DISPLAY

LCD701

LED DRIVE

Q702

90 LCD_AO
88 LCD-CS
89 LCD-RES
91 LCD-WR

86 BLIT

RADIO

TU +9V

CONTROL

Q329

B+ SWITCH

Q328

RDS +3.3V

63

TUNER ON/OFF

B+ SWITCH

Q327

VOLUME

PUSH ENTER/MEMORY

S701 – 716,

S762 – 766

(FRONT PANEL KEYS)

SUB +3.3V

ROTARY

ENCODER

S722

ROTARY

ENCODER

S721

REMOTE CONTROL

RECEIVER

IC701

X301

32.768kHz

X302

4.19MHz

SHIFT

CLOCK

Q333, 335

Q325

25 M_VOL-A
26 M_VOL-B

43 JOG-A
44 JOG-B

KEY-0 – KEY-2

38 – 40

REMOCON-IN

64

X1A

79

80

X0A

X1

83

X0

82

SHIFT CLOCK

53

SEL

41

INI

78

CD-IMONITOR

CD-ON

T-MOT

RELAY

RESET

AC-CHK

Q330

CURRENT
MONITOR

Q322

CD +3.3V

CD ON/OFF

CONTROL

LED DRIVE

Q701

Q320

REGULATOR
IC311, Q331

CD +1.5V

24

30

75

46

77

54

+3.3V

RESET SIGNAL

+4V

B+ SWITCH

Q319

CD +7V

M +10V

A +9V

D701

STANDBY

REGULATOR

SUB +3.3V

UCOM +3.3V

GENERATOR

IC304

+1.5V

IC706

CD +3.3V

REGULATOR

IC308

B+ SWITCH

Q326

CD +6V

+10V

MOTOR B+

SWITCH

Q317, 318

B+ SWITCH

Q316, 321

+4V

D309, 310

SUB +3.9V

D320

D325

D317

D311

D313D312

REGULATOR

IC307

+10V

REGULATOR

IC306

AMP B+
AMP B–

POWER ON

MUTING

Q505

PW MUT

PROTECT

REGULATOR

+4V

AC IN DETECT

Q336, 337

+7V

+14V

+3.9V

IC305

SUB B+

D506

D515

D321, 322

RECT

D602 - 605

RECT
D601

RECT

D507, 508

D611 - 614

D513, 514

RECT

RECT

MAIN POWER

TRANSFORMER

F601, 602

RELAY DRIVE

Q309, 312

TRANSFORMER

T601

SUB POWER

T602

RY601

P-ON MUT,

PROTECT

F603

STBY

(AC IN)

B

C

(Page 21)

(Page 21)

CMT-A50/A70

2222

• Note for Printed Wiring Boards and Schematic Diagrams • Circuit Boards Location

CMT-A50/A70

Note on Printed Wiring Board:

• X : parts extracted from the component side.

• Y : parts extracted from the conductor side.

• W : indicates side identified with part number.

f

•

• : Pattern from the side which enables seeing.

(The other layers' patterns are not indicated.)

Caution:
Pattern face side: Parts on the pattern face side seen from
(Conductor Side) the pattern face are indicated.
Parts face side: Parts on the parts face side seen from
(Component Side) the parts face are indicated.

• Indication of transistor.

: internal component.

C
Q

B

E

Q

B

CE

These are omitted.

These are omitted.

Note on Schematic Diagram:

• All capacitors are in µF unless otherwise noted. (p: pF)
50 WV or less are not indicated except for electrolytics
and tantalums.

• All resistors are in Ω and 1/
specified.

• f : internal component.

• 2 : nonflammable resistor.

• 5 : fusible resistor.

• C : panel designation.

Note:

The components identi­fied by mark 0 or dotted
line with mark 0 are criti­cal for safety.
Replace only with part
number specified.

• A : B+ Line.

• B : B– Line.

• Voltages and waveforms are dc with respect to ground

under no-signal conditions.
– CD Board –
no mark : CD PLAY
– Other Boards –
no mark : FM
(): CD PLAY
[]: TAPE PLAY

〈〈 〉〉 : TAPE REC

∗ : Impossible to measure

• Voltages are taken with a V OM (Input impedance 10 MΩ).

Voltage variations may be noted due to normal produc­tion tolerances.

• Waveforms are taken with a oscilloscope.
Voltage variations may be noted due to normal produc­tion tolerances.

• Circled numbers refer to waveforms.

• Signal path.

F : TUNER
E : TAPE PLAY
a : TAPE REC
J : CD PLAY (ANALOG OUT)
c : CD PLAY (DIGITAL OUT)
f : LINE IN

• Abbreviation
AUS: Australian model
CND : Canadian model
EE : East European model
IT : Italian model
KR : Korean model
RU : Russian model

4

W or less unless otherwise

Note:

Les composants identifiés par
une marque 0 sont critiques
pour la sécurité.
Ne les remplacer que par une
pièce portant le numéro
spécifié.

– Main unit –

SUB board

TOP KEY board

TUNER

KEY board

MAIN board

LOADING board

JACK board

CD board

– Speaker unit (L-CH) (CMT-A50) – – Speaker unit (L-CH) (CMT-A70) –

AMP board

AMP board

CMT-A50/A70

SPK board

POWER board

SPK board

2323