Sony SCD-XB940 User manual

SERVICE MANUAL
SUPER AUDIO CD PLAYER
AEP Model
UK Model
SPECIFICATIONS
SCD-XB940
Model Name Using Similar Mechanism NEW
CD Mechanism Type CDM55B-DVBU3
Base Unit Name DVBU3
Optical Pick-up Name KHM-220AAA/J1N
– Continued on next page –
Photo: Black type
Ver 1.1 2002.05
9-929-212-12 Sony Corporation
2002E0500-1 Home Audio Company
C2002.05 Published by Sony Engineering Corporation

2
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK 0OR DOTTED
LINE WITH MARK 0ON 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.
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.
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.
CAUTION
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous ra-
diation exposure.

3
TABLE OF CONTENTS
1. SERVICING NOTES ............................................... 4
2. GENERAL ................................................................... 5
3. DISASSEMBLY ......................................................... 8
4. DIAGRAMS
4-1. Notes for Printed Wiring Board and
Schematic Diagram ......................................................... 11
4-2. Printed Wiring Board – TK Board –.............................. 12
4-3. Schematic Diagram – TK Board – ................................ 13
4-4. Printed Wiring Board
– MAIN Board (Component Side) – .............................. 14
4-5. Printed Wiring Board
– MAIN Board (Conductor Side) – ................................ 15
4-6. Schematic Diagram – MAIN Board (1/6) – .................. 16
4-7. Schematic Diagram – MAIN Board (2/6) – .................. 17
4-8. Schematic Diagram – MAIN Board (3/6) – .................. 18
4-9. Schematic Diagram – MAIN Board (4/6) – .................. 19
4-10. Schematic Diagram – MAIN Board (5/6) – .................. 20
4-11. Schematic Diagram – MAIN Board (6/6) – .................. 21
4-12. Printed Wiring Board – AUDIO Board – ...................... 22
4-13. Schematic Diagram – AUDIO Board – ......................... 23
4-14. Printed Wiring Board – HP Board – .............................. 24
4-15. Schematic Diagram – HP Board –................................. 24
4-16. Printed Wiring Board – LOADING Board –................. 25
4-17. Schematic Diagram – LOADING Board – ................... 25
4-18. Printed Wiring Board – DISPLAY Board – .................. 26
4-19. Schematic Diagram – DISPLAY Board – ..................... 27
4-20. Printed Wiring Board – POWER Board – ..................... 28
4-21. Schematic Diagram – POWER Board –........................ 29
4-22. Printed Wiring Boards
– AC SW/TRANSFORMER Boards – ........................... 30
4-23. Schematic Diagram
– AC SW/TRANSFORMER Boards – ........................... 31
5. EXPLODED VIEWS................................................ 36
6. ELECTRICAL PARTS LIST ............................... 40

4
The laser diode in the optical pick-up block may suffer electro-
static 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 emis-
sion, observe from more than 30 cm away from the objective lens.
MODEL IDENTIFICATION
– Back Panel –
SECTION 1
SERVICING NOTES
NOTES ON HANDLING THE OPTICAL PICK-UP
BLOCK OR BASE UNIT
Part No.
HOW TO OPEN THE TRAY WHEN POWER SWITCH
TURNS OFF
There are two different methods to open the tray.
• Method-1
Insert a screw driver (3) into the aperture of the unit bottom, and
turn it in the direction of the arrow (to OUT direction).
tray
screw driver (3)
*To close the disc table, turn the screw driver (3)
in the reverse direction
(
to IN direction
)
.
Model Part No.
AEP 4-227-711-0 s
UK 4-227-711-1 s
tray
A
B
cam (CDM55)
screw driver (3)
• Method-2
1Insert a screw driver (3) into the aperture of the unit bottom,
and move the cam (CDM55) in the direction of arrow A.
2Pull the tray in the direction of arrow B.
ABOUT THE “E01” DISPLAY
“E01” is displayed when the above occurs in communication with
a system controller (IC605) and a display controller (IC203) at the
time of starting.
In this case, please check soldering, disconnection, etc. of each
IC.
Ver 1.1

5
SECTION 2
GENERAL This section is extracted from
instruction manual.

6

7

8
4connector
(CN992)
4connector
(CN351)
7two claws
2loading panel ass’y
qd front panel section
9knob (AMS)
6seven screws
(BV/RING)
qa connector
(CN201)
qs DISPLAY board
q; eight screws
(BVTP2.6 ×8)
7two claws
3wire (flat type) (10 core
)
(CN601)
5holder
1Pull out the tray.
(Refer to page 4, “HOWTO OPEN THE
TRAY WHEN POWER SWITCH TRANS OFF”.)
q; five screws
(BVTP2.6 ×8)
8
COVER (4095269)
FRONT PANEL SECTION
Note: Follow the disassembly procedure in the numerical order given.
SECTION 3
DISASSEMBLY
1two screws
1two screws
1two screws
1two screws
3cover (4095269
)
2
2

9
AUDIO/MAIN BOARD
MECHANISM DECK (CDM55B-DVBU3)
6three connectors
(CN301, 304, 351)
2two wires (flat type) (18 core)
(CN602, 603)
3two connectors
(CN605, 610)
4five screws
(BVTT3 ×8)
5MAIN board
9two PC board holders
7three screws
(BV/RING)
2wire (flat type) (10 core)
(CN601)
2two wires (flat type) (16 core)
(CN608, 611)
q; AUDIO board
8screw
(BVTT3 ×8)
1Pull out the tray.
(Refer to page 4, “HOW TO OPEN THE
TRAY WHEN POWER SWITCH TRANS OFF”.)
5screw
(BVTT3 ×8)
6mechanism deck
(CDM55B-DVBU3)
4connector
(CN605)
3two wires (flat type) (18 core)
(CN602, 603)
2loading panel ass’y
1Pull out the tray.
(Refer to page 4, “HOW TO OPEN THE
TRAY WHEN POWER SWITCH TRANS OFF”.)

10
TRAY
1Remove the tray. (Careful of the claw.)
claw
claw

1111
SECTION 4
DIAGRAMS
4-1. NOTE FOR PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS
Note on Printed Wiring Board:
•X: parts extracted from the component side.
•Y: parts extracted from the conductor side.
•a:Through hole.
•b: Pattern from the side which enables seeing.
(The other layers' patterns are not indicated.)
Caution:
Pattern face side: Partsonthe pattern facesideseenfrom
(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.
• Main board is multi-layer printed board.
However, the patterns of intermediate-layer have not been in-
cluded in the diagram.
• Indication of transistor
C
BThese are omitted. E
Q
Note on Schematic Diagram:
• All capacitors are in µF unless otherwise noted. pF: µµF
50 WV or less are not indicated except for electrolytics
and tantalums.
• All resistors are in Ωand 1/4W or less unless otherwise
specified.
•f: internal component.
•5: fusible resistor.
•C: panel designation.
•U: B+ Line.
•V: B– Line.
• Voltages and waveforms are dc with respect to ground
under no-signal conditions.
no mark : STOP
• Voltages aretaken withaVOM(Inputimpedance 10MΩ).
Voltage variations may be noted due to normal produc-
tion tolerances.
• Waveforms are taken with a oscilloscope.
Voltage variations may be noted due to normal produc-
tion tolerances.
• Circled numbers refer to waveforms.
• Signal path.
J: SACD
c: CD
I: DIGITAL OUT
• Circuit Boards Location
TRANSFORMER board POWER board
TK board
AUDIO boar
d
MAIN board
DISPLAY board
LOADING board
HP board
AC SW board
Note: The components identified by mark 0or dotted line
with mark 0are critical for safety.
Replace only with part number specified.

1212
SCD-XB940
4-2. PRINTED WIRING BOARD –TK Board – • See page 11 for Circuit Boards Location.
(Page 14)
(Page 14)

1313
SCD-XB940
4-3. SCHEMATIC DIAGRAM – TK Board – • See page 32 forWaveforms.
The components identified by mark 0or dotted
line with mark 0are critical for safety.
Replaceonlywith part numberspecified.
(Page 16)
(Page 16)

1414
SCD-XB940
4-4. PRINTED WIRING BOARD – MAIN Board (Component Side) – • See page 11 for Circuit Boards Location.
• Semiconductor
Location
Ref. No. Location
IC605 G-7
IC607 F-4
IC612 D-6
IC617 B-6
IC621 B-7
IC622 D-3
IC632 D-9
(Page 12)
(Page 12)
(Page 28)
(Page 25) (Page 26)
(Page 22) (Page 22)

1515
SCD-XB940
4-5. PRINTED WIRING BOARD – MAIN Board (Conductor Side) – • See page 11 for Circuit Boards Location.
• Semiconductor
Location
Ref. No. Location
D600 G-3
D604 G-3
D605 E-3
D606 G-2
D607 E-2
D608 G-2
D609 G-3
D610 G-3
D612 G-9
IC600 G-6
IC606 G-6
IC609 D-9
IC610 F-4
IC613 G-4
IC614 F-2
IC615 G-2
IC616 C-2
IC618 C-4
IC619 E-1
IC620 A-4
IC623 C-6
IC624 A-7
IC625 B-6
IC627 B-4
IC628 D-3
IC629 B-4
IC630 B-4
Q601 G-3
Q602 E-4
Q603 F-4

1616
SCD-XB940
4-6. SCHEMATIC DIAGRAM – MAIN Board (1/6) – • See page 32 forWaveforms.
(Page 29)
(Page 13)
(Page 13)
(Page 27)
(Page 19) (Page 20)
(Page 21)
(Page
20)
(Page 20)
(Page 17)
(Page 18)

1717
SCD-XB940
4-7. SCHEMATIC DIAGRAM – MAIN Board (2/6) –
(Page 16)
(Page 20)
(Page 21)
(Page 18)
(Page 21)

1818
SCD-XB940
4-8. SCHEMATIC DIAGRAM – MAIN Board (3/6) – • See page 32 forWaveforms. •See page 34 for IC Block Diagram.
(Page 16)
(Page 17)
(Page 19)
(Page 20)
(Page 21)
(Page 23)
(Page 23)
(Page 25)

1919
SCD-XB940
4-9. SCHEMATIC DIAGRAM – MAIN Board (4/6) – • See page 32 forWaveform.
(Page 16)
(Page 18)
(Page 20)

2020
SCD-XB940
4-10. SCHEMATIC DIAGRAM –MAIN Board (5/6) –
(Page 16)
(Page 19)
(Page 17) (Page 16) (Page 16)
(Page 18)
(Page 21)