background image
SERVICE MANUAL
PERSONAL COMPONENT SYSTEM
US Model
Canadian Model
Australian Model
CMT-A70
AEP Model
UK Model
CMT-A50/A70
E Model
CMT-A50
SPECIFICATIONS
CMT-A50/A70
Photo: CMT-A50
Ver. 1.1 2005.02
9-879-211-02
2005B05-1
© 2005.02
Sony Corporation
Personal Audio Group
Published by Sony Engineering Corporation
US and foreign patents licensed from Dolby Laboratories.
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)
530 - 1 610 kHz (10 kHz step)
IF
FM: 10.7 MHz
AM: 450 kHz
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
(CMT-A50)
2.5 cm dia., 6
(CMT-A70)
Woofer: 13 cm dia., 6
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
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
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.
(US model only)
POWER OUTPUT AND TOTAL HARMONIC
DISTORTION
AUDIO POWER SPECIFICATIONS
With 6
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.
Model Name Using Similar Mechanism
NEW
CD
CD Mechanism Type
FLM-A50
Section
Optical Pick-up Block Name
KSM-213CCP or KSM-213RCP
Optical Pick-up Name
KSS-213C or KSS-213R
Tape deck
Model Name Using Similar Mechanism
NEW
Section
Tape Transport Mechanism Type
CMAL1Z252A


background image
2
CMT-A50/A70
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 manufacturers' instructions to use these
instruments.
2. A battery-operated AC 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 AC voltmeter. The "limit" indication
is 0.75 V, so analog meters must have an accurate low-voltage
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)
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.
UNLEADED SOLDER
Boards requiring use of unleaded solder are printed with the lead-
free 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.
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.
Fig. A.
Using an AC voltmeter to check AC leakage.
1.5 k
0.15
µF
AC
voltmeter
(0.75 V)
To Exposed Metal
Parts on Set
Earth Ground
ATTENTION AU COMPOSANT AYANT RAPPORT
À LA SÉCURITÉ!
LES COMPOSANTS IDENTIFIÉS PAR UNE MARQUE 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 DANS LES SUPPLÉMENTS
PUBLIÉS PAR SONY.


background image
3
CMT-A50/A70
TABLE OF CONTENTS
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


background image
4
CMT-A50/A70
Power requirements
indication
­ Left Speaker Back Panel ­
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 pick-
up 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.
NOTES ON HANDLING THE OPTICAL PICK-UP
BLOCK OR BASE UNIT
SECTION 1
SERVICING NOTES
· MODEL IDENTIFICATION
Model
Destination
Power Requirements
Indication
CMT-A50
AEP, UK, Italian,
AC: 230V-50Hz 50W
East European
and Russian models
Korean model
AC: 220V-60Hz 50W
CMT-A70
US and Canadian model
AC: 120V 60Hz 100W
AEP, UK, Italian,
East European, Russian
AC: 230V-50Hz 100W
and Australian models
HOW TO OPEN THE CD TRAY WHEN POWER SWITCH TURNS OFF.
1
Using a flat-tip screwdriver of the diameter
less than 4 mm, rotate the gear in the arrow
direction.
2
Pull-out the CD tray.
Ver. 1.1


background image
5
CMT-A50/A70
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.
DISPLAY
1 Press DISPLAY when the player is
turned off.
2 Turn the jog dial to select "CD
RESUME OFF".
"OFF" flashes on the display.
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.
Jog dial
(PUSH ENTER/
MEMORY)
Adjusting the contrast
of the display
+
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.
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.
Jog dial (PUSH
ENTER/
MEMORY)
DISPLAY