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MICROFILM
SERVICE MANUAL
COMPACT DISC CHANGER
US Model
Canadian Model
E Model
SPECIFICATIONS
CDX-838
Model Name Using Similar Mechanism
NEW
CD Drive Mechanism Type
MG-250D-137
Optical Pick-up Name
KSS-521A/J2N


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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.
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 PUB-
LISHED BY SONY.
TABLE OF CONTENTS
1.
SERVICING NOTES ................................................ 2
2.
GENERAL ................................................................... 3
Installation .......................................................................
4
Connections .....................................................................
5
3.
DISASSEMBLY ......................................................... 6
4.
MECHANISM DECK ASSEMBLY ..................... 12
5.
MECHANICAL ADJUSTMENTS ....................... 14
6.
ELECTRICAL ADJUSTMENTS ......................... 15
7.
DIAGRAMS
7-1. Block Diagram ­ SERVO Section ­ ............................... 16
7-2. Block Diagram ­ MAIN Section ­ ................................. 17
7-3. Block Diagram
­ BUS CONTROL/POWER SUPPLY Section ­ ........... 18
7-4. Note for Printed Wiring Boards and
Schematic Diagrams ....................................................... 19
7-5. Printed Wiring Boards ­ RF/SW Boards ­ ..................... 20
7-6. Schematic Diagram ­ RF/SW Boards ­ ......................... 21
7-7. Printed Wiring Boards
­ MAIN Board (Component Side) ­ .............................. 22
7-8. Printed Wiring Board
­ MAIN Board (Conductor Side) ­ ................................ 23
7-9. Schematic Diagram ­ MAIN Board (1/3) ­ ................... 24
7-10. Schematic Diagram ­ MAIN Board (2/3) ­ ................... 25
7-11. Schematic Diagram ­ MAIN Board (3/3) ­ ................... 26
7-12. Printed Wiring Boards
­ DIGITAL OUT /JACK Boards ­ ................................. 28
7-13. Schematic Diagram
­ DIGITAL OUT /JACK Boards ­ ................................. 29
7-14. IC Pin Function Description ........................................... 33
8.
EXPLODED VIEWS ................................................ 36
9.
ELECTRICAL PARTS LIST ............................... 41
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 electro-
static breakdown because of the potential difference generated by
the charged electrostatic load, etc. on clothing and the human body.
During repair, pay attention to electrostatic breakdown 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.
Laser Diode Properties
· Material: GaAlAs
· Wavelength: 780 nm
· Emission Duration: continuous
· Laser Output Power: less than 44.6 µW*
* This output is the value measured at a distance of 200 mm
from the objective lens surface on the Optical Pick-up Block.
CAUTION
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous ra-
diation exposure.
Flexible Circuit Board Repairing
· Keep the temperature of the soldering iron around 270 °C dur-
ing 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.
Notes on chip component replacement
· Never reuse a disconnected chip component.
· Notice that the minus side of a tantalum capacitor may be dam-
aged by heat.
DISC MAGAZINE GETTING OUT PROCEDURE
ON THE POWER SUPPLY IS OFF
Remove the CASE (LOWER) assembly beforehand
1) Press the lever (ML) assy to arrow direction.
2) Removal the magazine assy.
Note: Take out the magazine only when the tray is completely within the
magazine. If the disk or tray is sticking out, turn on the power and
eject the magazine.
Magazine ass'y
Lever (ML) ass'y


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SECTION 2
GENERAL
This section is extracted from
instruction manual.


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