Sony CDP-CX240 User manual

– 1 –
MICROFILM
CDP-CX240
US Model
Canadian Model
SPECIFICATIONS
SERVICE MANUAL
COMPACT DISC PLAYER
Model Name Using Similar Mechanism CDP-CX250
CD Mechanism Type CDM-40B
Base Unit Type KSM-213BKN/M-N
Optical Pick-up Type KSS-213B/S-N

– 2 –
CAUTION
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous ra-
diation exposure.
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 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.
Laser component in this product is capable of emitting radiation
exceeding the limit for Class 1.
This appliance is classified as
a CLASS 1 LASER product.
The CLASS 1 LASER PROD-
UCT MARKING is located on
the rear exterior.
The following
caution label is
located inside of
the unit.
PARTS No. MODEL
MODEL IDENTIFICATION
— BACK PANEL —
4-999-020-0π
4-999-020-1πUS
Canadian
SAFETY-RELATED COMPONENT WARNING !!
COMPONENTS IDENTIFIED BY MARK !OR DOTTED LINE
WITH MARK !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
À LA SÉCURITÉ!!
LESCOMPOSANTSIDENTIFIÉSPARUNEMARQUE!SUR
LES DIAGRAMMES SCHÉMATIQUES ET LA LISTE DES
PIÈCES SONT CRITIQUES POUR LA SÉCURITÉ DE
FONCTIONNEMENT.NEREMPLACER CES COMPOSANTS
QUE PAR DES PIÈCES SONY DONT LES NUMÉROS
SONT DONNÉS DANS CE MANUEL OU DANS LES
SUPPLÉMENTS PUBLIÉS PAR SONY.
SAFETY CHECK-OUT
After correcting the original service problem, perform the follow-
ing safety checks before releasing the set to the customer:
Checktheantenna terminals, metaltrim,“metallized”knobs, screws,
and all other exposed metal parts forAC leakage. Check leakage as
described below.
LEAKAGE
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 tochassis, must not exceed 0.5mA (500microampers). Leak-
age 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 aVOM
or battery-operatedAC 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 pas-
sive VOM that is suitable. Nearly all battery operated digital
multimeters that have a 2V AC range are suitable. (See Fig. A)
Fig. A. Using an AC voltmeter to check AC leakage.
PART NO.
0.15 µ F
To Exposed Metal
Parts on Set
1.5k
Ω
AC
voltmeter
(0.75V)
Earth Ground

– 3 –
TABLE OF CONTENTS
1. SERVICING NOTE .......................................................... 3
2. GENERAL .......................................................................... 6
3. DISASSEMBLY
3-1. Front Panel Assembly ........................................................... 7
3-2. Back Panel Assembly............................................................ 7
3-3. Base (Door, Gear) Assembly ................................................ 8
3-4. Table Assembly ..................................................................... 8
3-5. Mechanism Deck .................................................................. 9
3-6. Base Unit ............................................................................. 9
4.TEST MODE ..................................................................... 10
5. ADJUSTMENTS
5-1. MechanicalAdjustment ...................................................... 13
5-2. Electrical Block Checking .................................................. 19
6. DIAGRAMS
6-1. Circuit Boards Location...................................................... 22
6-2. Block Diagrams
• BD Section........................................................................ 23
• Main Section..................................................................... 25
6-3. Schematic Diagram – BD Section – ................................... 29
6-4. Printed Wiring Board – BD Section –................................. 31
6-5. Printed Wiring Board – Main Section –.............................. 33
6-6. Schematic Diagram – Main (1/2) Section –........................ 35
6-7. Schematic Diagram – Jack Section –.................................. 37
6-8. Printed Wiring Board – Jack Section – ...............................39
6-9. Schematic Diagram – Display Section – ............................ 41
6-10. Printed Wiring Board – Display Section –........................ 43
6-11. Schematic Diagram – Sensor/Motor Section – ................. 45
6-12. Printed Wiring Board – Sensor/Motor Section – .............. 46
6-13. IC Block Diagrams............................................................ 47
6-14. IC Pin Functions................................................................ 49
7. EXPLODEDVIEWS
7-1. Case and Back Panel Section.............................................. 54
7-2. Disc Table Section .............................................................. 55
7-3. Front Panel Section .............................................................56
7-4. Mechanism Section-1 (CDM-40B)..................................... 57
7-5. Mechanism Section-2 (CDM-40B)..................................... 58
7-6. Mechanism Section-3 (CDM-40B)..................................... 59
7-7. Base Unit Section (KSM-213BKN/M-N)........................... 60
8. ELECTRICAL PARTS LIST ........................................ 61
SECTION 1
SERVICING NOTE
NOTES ON HANDLINGTHE 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
repain 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, ob-
serve from more than 30 cm away from the objective lens.
The emission check enables continuous checking of the S curve.
LASER DIODE AND FOCUS SEARCH OPERATION
CHECK
Carry out the “Scurve check” in “CDsection adjustment”and check
that the S curve waveform is output three times.

– 4 –
CD-TEXTTEST DISC
This unit is able to display the TEXT data (character information) written in the CD on its fluorescent indicator tube.
The CD-TEXT TEST DISC (TGCS-313:J-2501-126-A) is used for checking the display.
To check, perform the following procedure.
Checking Method:
1. Turn ON the power, set the disc on the disc table with the side labeled as “test disc” as the right side, close the front cover, and chuck the
disc.
2. The following will be displayed on the fluorescent indicator tube. (The display switches each time the TIME/TEXT button is pressed.)
Display : Main Artist Test or CD TEXT TEST DISC (Album Title)
3. Press the ”button and play back the disc.
4. The following will be displayed on the fluorescent indicator tube. (If nothing is displayed, press the TIME/TEXT button.)
Display : 1kHz/0 dB/ L&R
5. Rotate ≠and ±buttons to switch the track. The text data of each track will be displayed.
For details of the displayed contents for each track, refer to “Table 1 : CD-TEXT TEST DISC TEXT Data Contents” and “Table 2 : CD-
TEXT TEST DISC Recorded Contents and Display”.
Restrictions in CD-TEXT Display
In this unit, some special characters will not be displayed properly. These will be displayed as a space or a character resembling it. For details,
refer to “Table 2 : CD-TEXT DISC Recorded Contents and Display”.
Table 1 : CD-TEXTTEST DISCTEXT Data Contents (TRACKS No. 1 to 41:Normal Characters)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
TRACK
No. Displayed Contents
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
TRACK
No. Displayed Contents
1kHz/0dB/L&R
20Hz/0dB/L&R
40Hz/0dB/L&R
100Hz/0dB/L&R
200Hz/0dB/L&R
500Hz/0dB/L&R
1kHz/0dB/L&R
5kHz/0dB/L&R
7kHz/0dB/L&R
10kHz/0dB/L&R
16kHz/0dB/L&R
18kHz/0dB/L&R
20kHz/0dB/L&R
1kHz/0dB/L&R
1kHz/-1dB/L&R
1kHz/-3dB/L&R
1kHz/-6dB/L&R
1kHz/-10dB/L&R
1kHz/-20dB/L&R
1kHz/-60dB/L&R
1kHz/-80dB/L&R
1kHz/-90dB/L&R
Infinity Zero w/o emphasis//L&R
Infinity Zero with emphasis//L&R
400Hz+7kHz(4:1)/0dB/L&R
400Hz+7kHz(4:1)/-10dB/L&R
19kHz+20kHz(1:1)/0dB/L&R
19kHz+20kHz(1:1)/-10dB/L&R
100Hz/0dB/L*
1kHz/0dB/L*
10kHz/0dB/L*
20kHz/0dB/L*
100Hz/0dB/R*
1kHz/0dB/R*
10kHz/0dB/R*
20kHz/0dB/R*
100Hz Squer Wave//L&R
1kHz Squer Wave//L&R
1kHz w/emphasis/-0.37dB/L&R
5kHz w/emphasis/-4.53dB/L&R
16kHz w/emphasis/-9.04dB/L&R
NOTE : The contents of Track No. 1 to 41 are the same as those of the current TEST DISC-their titles are displayed.

– 5 –
TRACK
No. Recorded contents Display
NAll the same
NAll the same
NAll the same
NAll the same
NAll the same
NAll the same
NAll the same
X Y Z [ \ ] ^ _ (58····
NAll the same
NAll the same
NAll the same
xyz{I}~(78····
(A0···· is not displayed
≥(A8···· Cª¬PR–are not displayed
µ• (B0···· •±23¶are not displayed
† ¿ (B8···· 1ºare not displayed
NAll the same
NAll the same
NAll the same
ΦÙÚÛÜY ß (D8····
NAll the same
NAll the same
∂ñòóôoö÷(F0····
NAll the same
NAll the same
NAll the same
to
NAll the same
′
*
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
to
99
! ” # $%& ´ (21h to 27h)1kHz 0dB L&R
( ) + , – . / (28h to 2Fh)
01234567 (30h to 37h)
89: ;<=>? (38h to 3Fh)
@A B C D E F G (40h to 47h)
H I J K L MNO (48h to 4Fh)
PQRSTUVW (50h to 57h)
X Y Z [ ¥ ] ^ _ (58h to 5Fh)
a b c d e f g (60h to 57h)
h i j k l m n o (68h to 6Fh)
p q r s t u v w (70h to 77h)
xyz{ I} (78h to 7Fh)
i¢£¤¥ § (A0h to A7h) 8859-1
≥Cª¬PR–(A8h to AFh)
•±23 µ¶ • (B0h to B7h)
†1º¿ (B8h to BFh)
ÀÁÂÃÄÅÆÇ (C0h to C7h)
ÈÉÊË ÌÍÎÏ (C8h to CFh)
DÑÒÓÔÕÖ (D0h to D7h)
ØÙÚÛÜY ß (D8h to DFh)
àáâãäåæç (E0h to E7h)
èéêëìíîï (E8h to FFh)
∂ñòóôõö÷(F0h to F7h)
øùúûüy ÿ (F8h to FFh)
No.66
No.67
to
No.99
~
′
1
41 23 4
′
˙
1
41 23 4
Table 2: CD-TEXT TEST DISC Recorded Contents and Display
(In this unit, some special characters cannot be displayed. This is no a fault.)
´
˙

– 6 –
LOCATION OF PARTS AND CONTROLS
11/u (power) button
2STANDBY indicator
3Display window
4Front cover
5MEGA control button and indicator
6X-FADE button
7INPUT button
8DISC/CHARACTOR dial and PUSH ENTER button
9FADER button
10 NO DELAY button
11 MEMO SEARCH button
12 CHECK button
13 CLEAR button
14 p(stop) button
15 P(pause) button and indicator
16 ·(play) button and indicator
17 ≠AMS ±button
18 §OPEN/CLOSE button
19 TIME/TEXT button
20 REPEAT button
21 PROGRAM button
22 SHUFFLE button
23 CONTINUE button
24 HIT LIST button and indicator
25 GROUP FILE button
26 GROUP 1 to 8 button and indicator
27 KEY BOARD jack
28 TIMER (OFF/PLAY) switch
* AMS is abbreviation for Automatic Music Sensor.
SECTION 2
GENERAL
Front Panel
345678
1
2
91011
12 13
1415161718
27
28
242526 1920212223

– 7 –
SECTION 3
DISASSEMBLY
Note : Follow the disassembly procedure in the numerical order given.
3-1. FRONT PANEL ASSEMBLY
3-2. BACK PANEL ASSEMBLY
1 Two screws
(BVTP3x8)
2 Two screws
(BVTP 3x8)
3 Four screws
(BVTT3x6)
5 Remove the cla
w
6 Remove the claw
7 Front panel assembly
4 Flat type wire (17 core)
(Main board, CN501)
5 Remove the PC board holder
7 Back panel
1 Connector (CN906)
2 Two screws
(BVTT3X6)
3 Seven screws
(BVTT3X6)
4 Three screws
(BV3X6)

– 8 –
3-3. BASE (DOOR, GEAR) ASSEMBLY
3-4.TABLE ASSEMBLY
2 Three screws (BVTT3x6)
3 Screw (PSW3x6)
4 Connector (CN503
)
5 Guide assembly
MAIN board
7 Three screws (BVTT3x6)
8 Three screws
(BVTT3x6)
6 Door (CD) assembly
9 Base (Door, Gear) assembly
1 Screw (BVTT3x6)
1 Stop ring (E type)
4 Table assembly
5 Washer
2 Two screws
(BVTT3x6)
3 Two holder assemblies

– 9 –
3-5. MECHANISM DECK
3-6. BASE UNIT
5 Mechanism deck
Jack board
Main board
Main boar
d
1 Flat type wire
(23core) (CN502)
4 Nine screws
(BVTT3x8)
2 Connector
(CN904)
3 Connector
(CN505)
1 Screw (BVTT3x6)
2 Fulcrum plate (BU Upper) assembly
3 Base uni
t

– 10 –
SECTION 4
TEST MODE
4-1. DISPLAY CHECK MODE
With the power turned off (standby state), press the 1/u button
while pressing the P(pause) button.
All FL segments and grids light up together with the ·(play),
P(pause), and STANDBY LEDs.
At the same time, the GROUP LEDs are lights up simultaneously.
Note: To exit this mode, press the p(stop) button.
4-2. ADJ MODE
1. Turn ON the power of the unit, set disc to disc table, and per-
form chucking.
2. Disconnect the power supply plug from the outlet.
3. To set ADJ mode, connect the test point (ADJ) of the MAIN
board toGround, andconnect thepowersupplyplugto theoutlet.
The power will turn on automatically, and the first track will be
played.
Inthis mode, tablerotationand loading operationsarenot performed
because it is taken that the disc has already been chucked.
Note:The same operationsarealso performedinthe followingwhen
the test point (ADJ) is connected to Ground after turning on
the power.
• Direct search (movement of sledding motor) is not performed dur-
ing accessing
• Ignored even when GFS becomes L
• Ignored even when the Q data cannot be read
• Focus gain does not decrease
• Spindle gain does not decrease
• Servo related settings can be set manually and checked (Refer to
ADJ Mode Special Functions Table)
ADJ Mode Special FunctionsTable
(The buttons shown with ( ) function by using the sup-
plied remote commander only)
4-3. KEY AND DISPLAY CHECK MODE
To set this mode, connect the test point (AFADJ) on the MAIN
board to Ground, and connect the power supply plug to the outlet.
• All FL segments and grids will light up. (All lit check)
When a button is pressed, the types of buttons pressed until then
will be displayed on the left side and the number of the buttons
will be displayed on the right side. However, these will not be
displayed for the following special buttons.
p(stop) button: FL segment check
(Refer to FL Tube Check Patterns)
P(pause) button: FL grid check
(Refer to FL Tube Check Patterns)
The pause LED also lights up simultaneously.
·(play) button: All FL segment and grid will light up.
The play LED also lights up simultaneously.
FLTube Check Patterns
Segment check
• When the jog dial is rotated to the right, the GROUP LEDs light
up in the order of 1n2..8n1.
• When the jog dial is rotated to the left, the GROUP LEDs light up
in the order of 8n7..1n8.
•Abbreviation
FL: Fluorescent Indicator Tube
[ MAIN BOARD ] – Component Side –
Button
CONTINUE
SHUFFLE
PROGRAM
GROUP 1 (1)
GROUP 2 (2)
GROUP 3 (3)
GROUP 4 (4)
GROUP 5 (5)
GROUP 6 (6)
GROUP 7 (7)
GROUP 8 (8)
(9)
(10/0)
CHECK
CLEAR
Function
Servo average display
Displays VC, FE, RF, TE and traverse in hexadecimal
numbers
Focus bias display
Eachtime this ispressed, the focusbias is switched
between 1 and 2
(1)
Bias actually set Optimum bias Minimum jitter
(2)
U:Upper aliasing bias L:Lower aliasing bias
Auto gain display
Displays focus, tracking, sledding in hexadecimal
numbers
Increases the focus bias in 8 steps.
Sets the focus bias in the middle of aliasing.
Turns off the tracking and sledding servo
Returns the auto gain to the initial value (30)
Turns off the focus servo
Decreases the focus bias in 8 steps.
Re-adjusts the focus bias
Turns on the tracking and sledding servo
Switches the focus servo gainbetweennormal anddown
FG. norm: normal, FG. down: down
Sets the focus bias to 0 (no bias)
Next, displays the jitter measured at the focus bias set
S-curve observation mode.
(Exits this mode when the pbutton is pressed.)
Automatic eccentric measurement
The results of measurement is displayed in µm directly.
Grid check
Magnified
ABCDE
16
RV501
DISC SENSOR
ADJUSTMENT
CN506
TP2
(AFADJ)
TP1
(ADJ)
R540
IC501 R531

– 11 –
4-4. AGING MODE
Aging Mode
• Mode which repeatedly changes and plays back discs automati-
cally in the unit.
• It will repeat aging as long as no errors occur.
• If an error occurs during aging, it will stop all servos,motors, etc.
instantaneously, display the error number, and stop operations.
However, the stopping conditions differ according to whether the
unit is equipped with the “self-protection function during errors”
described later.
The function serves to maintain the state of the unit when errors
occur.
Sequence of Aging Mode
$
$
$
1. Disc change
2. Load in
3. TOC read
4. Access of last track
5. 3 second playback
6. Access of first track
7. 3 second playback
8. Load out
9. FRONT COVER open
10. FRONT COVER close
$
$
$
$
$
$
Order of Disc Change
(1 cycle takes 3 minutes)
$
$
$
1. No. 40
2. No. 80
3. No. 120
4. No. 160
5. No. 200
$
$
$
Special Aging Mode Functions
Theaging mode isprovided with thefollowingconvenient functions
• Disc setting mode (*1)
• Selection of presence of protection function during error (*2)
• Count function of aging cycle (*3)
*1 Disc setting mode:
5 discs are set before setting the aging mode. This mode makes
the setting of these discs more easy.
*2 Self protection function during errors:
Function which voluntarily corrects errors which occur during
normal operations by retries.
If this function is not provided, all operations will be stopped
without retiring. It is suitable for checking errors with low re-
producibility.
Ifthis functionisprovided, anderrors canbecorrectedby retries,
aging will be continued without stopping.
*3 Aging cycle count function:
Functions which displays the number of agings carried out on
the Fluorescent indicator tube in numbers. One aging cycle con-
sists of five discs.
1DISC CD1
DISC 2
*DISC-40*
number of agings
$
$

– 12 –
Aging Method
1. Turn ON the power of the unit. Press the §OPEN/CLOSE and
open the front cover.
2. Change the COMMAND MODE switch (S901) on set to CD1 .
3. Press the AGING START button of the remote commander for
aging mode (J-2501-123-A).
4. When the disc set mode is set, the (and PLEDs blink.
5. Rotate the DISC/CHARACTER dial. The slits (No. 40, 80,
120,160, 200) for setting the discs will come forward. Insert the
discs into these slits. Do not set the discs in other slits.
6. Set whether the self-protectionfunction during errors isequipped
with the unit. Press the REPEAT button. If “REPEAT” is dis-
played on the Fluorescent indicator tube, it means the function
is provided. If “REPEAT” is not displayed,it means the function
is not provided.
Error Display
7. Press the (button.
8. The (LED blinks, the aging mode is set, and aging is started.
9. The aging cycle lasts 3 minutes. If errors occur during aging,the
error number will be displayed on the Fluorescent indicator tube.
(Refer to the following table for the details of the errors.)
10. Aging will be repeated as long as no errors occur.
11. After each aging cycle, the number displayed on the Fluorescent
indicator tube will increase.
12. To end aging, press the 1/u button.
120 Err01
  
  
Err 01
Err 02
Err 03
Err 04
Err 05
Err 06
Err *1
Err *2
Err *3
Err *4
Err *5
Err *6
Err *7
No disc in the specified slit
Disc in other slits
Table motor current over
No table sensor input
Load in timeover
Load out timeover
Access timeover
High speed search NG
Q data read error
BU operation (from focus search to until signal can be read) timeover
GFS monitor error
Focus cannot be imposed by focus search
Auto focus bias adjustment cannot be performed
ContentsCode number Name
DISC sensor check 1
DISC sensor check 2
Table operation check 1
Table operation check 2
Loading operation check 1
Loading operation check 2
BU related check 1
BU related check 2
BU related check 3
BU related check 4
BU related check 5
BU related check 6
BU related check 7
Error code
The * numbers mean the following according to the state of the unit during aging
2 : From chucking to end of TOC read
3 : From end of TOC read to end of last track playback
4 : From end of last track playback to end of first track playback
Disc number Error code

– 13 –
SECTION 5
ADJUSTMENTS
5-1. MECHANICAL ADJUSTMENT
Perform the following steps before carrying out adjustments.
1. Turn ON the power of the unit, set disc to disc table No. 92, and
perform chucking.
2. Turn OFF the power.
3. Remove the case.
4. While pressing the STOP button, turn ON the 1/u button.
The test mode is set.
5. The POWER button LED starts blinking.
(Test mode)
NOTE 1: Thecam will start rotating whenthe GROUP 1 or GROUP
5 button is pressed continuously in the test mode.
NOTE 2: If the power cannot be supplied, the cam can be rotated
by rotating the pulley with your finger.
GROUP 1
button
GROUP 5
button GROUP 1
button GROUP 5 button
LED
1/u button STOP button
Cam
Pulley

– 14 –
GUIDE (DISCT) ALIGNMENT
Cam
Cam Holder (guide T)
Fixed screw
Guide (disc T)
Guide (disc T)
Guide (disc T)
Disc
Disc
Holder
(guide T)
Holder (guide T)
Tapering screwdriver
AB
(1) Rotate the cam and adjust to the
position shown in the figure.
(2) Check that the state is as
shown in the figure.
(3) Loosen the fixed screw by about 60 °.
(4) Move the holder (guide T) with a tapering screwdriver,
and set the position of the guide (disc T) to A:B=1:1.

– 15 –
HOLDER (DISC A) ALIGNMENT
(1) Rotate the cam and adjust to the
position shown in the figure.
Cam
Cam Holder (disc A)
Thrust
screw
Disc
Disc
0 - 1mm
Holder (disc A)
Holder (disc A)
Thrust screw
(2) Check that the state is as shown in
the figure.
(3) After applying suitable locking compound to the part, rotate the thrust screw until the holder (DiscA) comes to the center of the disc.

– 16 –
(1) Rotate the cam and adjust to the
position shown in the figure.
SENSOR ALIGNMENT
Perform this adjustment after the “holder (discA) adjustment”.
If the disc table swings to the left and right just before the disc is
chucked, perform the following adjustment.
(2) Check that the lever (stopper) assembly
secures the disc table as shown in the figure.
(3) Loosen the fixed screw by 60°to 90°, and use a tapering screwdriver to adjust the screw as shown in the figure.
Move the bracket (sensor) with the tapering screwdriver little by little, and fix the fixed screw at where the play button's LED (green) is
switched to the pause button's LED (orange) (or its reverse).
CAUTION:
The LED may not light up in steps (3) and (4) for some
microprocessor versions, and consequently adjustments will not
be possible.
In this case, fix the bracket (sensor) at the mechanical center.
As fine adjustments need to be performed in “Disc Sensor
Adjustment” in Electrical Adjustments, sensor alignment need
not be performed here.
(4) Moving the disc table right and left with a hand after the screw
is fixed, the table will move by the play of a disc table. If the
LEDs light up alternately, the adjustment will be performed
correctly.
Cam
Cam
Bracket (sensor)
Table assembly
Swing
PAUSE buttonPLAY button
Disc table
Lever (stopper) assembly
Tapering screwdriver
Luminus board
Bracket (sensor)
Fixed screw
Lever (stopper)
assembly

– 17 –
PULLY AND DISC CENTER HOLE ALIGNMENT
Cam
Disc
0.5 - 2mm
Base unit
Disc pulley
Bracket
(BU adjustment)
Tapering screwdriver
Magnet assembly
AB
Disc hole
Holder (disc A)
Fixed screw
Cam Base unit
Bracket
(BU adjustment)
Magnet assembly
(1) Rotate the cam and adjust to the
position shown in the figure.
(2) Check that the state is as shown
in the figure.
Note:The disc should not
be fixed.
Loosen the fixed screw by 60°to 90°, and move and adjust the
bracket (BU adjustment) up and down using a tapering screwdriver
so that the positions of the disc hole and disc pulley become A=B
or between A:B=2:1 and 1:2.
(3) Remove the Magnet assembly.

– 18 –
MAGNET ASSY ALIGNMENT
Cam
Cam
Adjustment
screw
Magnet assembly
Magnet assembly
Adjustment
screw
Adjustment
screw
AB
Magnet holder Disc
(1) Rotate the cam and adjust to the
position shown in the figure.
(2) Rotate the adjustment screw untilA=B or between
A:B=2:1 and 1:2
(3) Apply suitable lockingcompaund to the partafter adjusting.

– 19 –
5-2. ELECTRICAL BLOCK CHECKING
Note:
1. CD Block is basically designed to operate without adjustment.
Therefore, check each item in order given.
2. UseYEDS-18 disc (3-702-101-01) unless otherwise indicated.
3. Use an oscilloscope with more than 10MΩimpedance.
4. Clean the object lens byan applicator with neutraldetergent when
the signal level is low than specified value with the following
checks.
S-Curve Check
Procedure :
1. Chuckthedisc (YEDS-18) beforehand,anddisconnectthe power
cord from the outlet.
2. Connect oscilloscope to test point TP (FE1) on BD board.
3. Connect test point TP1 (ADJ) on MAIN board to ground with
lead wire.
4. The ADJ mode is set when the power cord is inserted into the
outlet and power is supplied.
5. The fifth track is played automatically.
6. Press the CHECK button.
7. Check the oscilloscope waveform (S-curve) is symmetrical be-
tweenA and B.And confirm peak to peak level within 3±1Vp-p.
S-curve waveform
8. Pressingthe pbuttonstops theoutputof the waveform(s curve).
9. After check, remove the lead wire connected in step 3.
Note : • Try to measure several times to make sure than the ratio of
A : B or B :A is more than 10 : 7.
• Take sweeptime as long aspossibleandlight up the bright-
ness to obtain best waveform.
RF Level Check
Note: A clear RF signal waveform means that the shape “◊” can be
clearly distinguished at the center of the waveform.
RF signal waveform
E-F Balance Check
Procedure :
1. Chuckthedisc(YEDS-18) beforehand, anddisconnectthe power
cord from the outlet.
2. Connect oscilloscpe to test point TP (TE) on BD board.
3. Connect test point TP1 (ADJ) on MAIN board to ground with
lead wire.
4. The ADJ mode is set when the power cord is inserted into the
outlet and power is supplied.
5. The fifth track is played automatically.
6. Press the GROUP 3 button. (The tracking servo and the sled-
ding servo are turned OFF.)
7. Check the level B of the oscilliscope's waveform and theA (DC
voltage) of the center of the Traverse waveform.
Confirm the following :
A/B x 100 = less than ± 22%
Traverse waveform
8. Press the GROUP 8 button. (The tracking servo and sledding
servo are turned ON.) Confirm the C (DC voltage) is almost
equal to the A (DC voltage) is step 7.
Traverse waveform
Procedure :
1. Connect oscilloscope to test point TP (RF) on BD board.
2. Turn Power switch on.
3. Put disc (YEDS-18) in to play the number five track.
4. Confirm that oscilloscope waveform is clear and check RF signal
level is correct or not.
9. Disconnect the lead wire of TP1 (ADJ) connected in step 2.
oscilloscope
BD board
TP (FE1)
TP (VC)
symmetry
A
B
Within 3
± 1 Vp-p
oscilloscope
BD board
TP (RF)
TP (VC)
VOLT/DIV : 200mV
TIME/DIV : 500ns
level : 1.2 Vp-p
+0.25
–0.20
oscilloscope
BD board
TP (TE)
TP (VC)
0V
level : 1.3 ± 0.6 mVp-p
A (DC voltage)
Center of the waveform
B
0V C (DC
voltage)
Tracking servo
Sledding servo
OFF
Tracking servo
Sledding servo
ON

– 20 –
Disc Sensor Adjustment
Perform this adjustment after completing all adjustments of the
mechanism section.
If not performed accurately, the presence of the disc may not be
detected properly.
Connection 1:
Waveform 1:
Connection 2:
Waveform 2
Procedure:
1. Connect the oscilloscope to Pins 1, 2, and 4of CN506 of the
MAIN board.Also connect a 1 kΩresistor to Pin 4at the same
time. (Connection 1)
2. Check that no discs are loaded in the unit.
3. With the power OFF, press the 1/u button while pressing the
INPUT button, and turn on the power at the same time.
4. The rotary table will continue rotating in the clockwise direction.
5. Observe the waveform at that time on the oscilloscope.
6. Loosen the screw securing the LUMINOUS board slightly.
7. Slide the LUMINOUS board to the left and right so that the
peak of the D0 waveform is at the center between the descending
point of the T1 waveform and ascending point of the T2
waveform. (Waveform 1) After adjusting, apply locking
compound.
8. Disconnect the resistor connected to Pin 4of CN506 of the
MAIN board. (Connection 2)
9. Observe the waveform on the oscilloscope. (Waveform 2)
10. Adjust RV501 of the MAIN board so that the waveform on the
oscilloscope satisfies the following adjustment value 1.
11. Press the 1/u button and turn OFF the power.
12. Press the 1/u button, turn on the power, press the OPEN/
CLOSE button, and open the front cover. Next rotate the DISC/
CHARACTER dial in the counterclockwise direction
continuously so that the rotary table rotates continuously in the
counterclockwise direction.
13. Observe the waveform on the oscilloscope and confirm that it
satisfies the adjustment value 2 (waveform 3). If it does not,
adjust RV501 of the MAIN board.
Waveform 3:
CN506 of MAIN board
T1 : Pin
1 (TS. 1)
T2 : Pin
2 (TS. 2)
D0 : Pin
4 (D. SENS)
oscilloscop
e
1 k Ω
AB
T1
T2
D
0
CN506 of MAIN board
T1 : Pin
1 (TS. 1)
T2 : Pin
2 (TS. 2)
D1 : Pin
4 (D. SENS)
oscilloscope
X
Z
Y
T1
T2
D1
LUMINOUS boar
d
X
Z
Y
T1
T2
D1