– 19 –
CD SECTION
Note:
1. CD Block is basically constructed to operate without adjustment.
Therefore, check each item in order given.
2. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
3. Use an oscilloscope with more than 10M
Ω
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.
S Curve Check
Procedure :
1. Connect oscilloscope to test point TP (FEO).
2. Connect between test point TP (FOK) and Ground by lead wire.
3. Turn Power switch on.
4. Put disc (YEDS-18) in and turned Power switch on again and
actuate the focus search. (actuate the focus search when disc
table is moving in and out.)
5. Check the oscilloscope waveform (S-curve) is symmetrical be-
tween A and B. And confirm peak to peak level within 3
±
1Vp-p.
S-curve waveform
6. After check, remove the lead wire connected in step 2.
Note:
• Try to measure several times to make sure than the ratio of
A : B or B : A is more than 10 : 7.
• Take sweep time as long as possible and light up the bright-
ness to obtain best waveform.
RF Level Check
Procedure :
1. Connect oscilloscope to test point TP (RF) on BD board.
2. Turned Power switch on.
3. Put disc (YEDS-18) in and playback.
4. Confirm that oscilloscope waveform is clear and check RF sig-
nal level is correct or not.
Note:
Clear RF signal waveform means that the shape “
◊
” can be
clearly distinguished at the center of the waveform.
RF signal waveform
VOLT/DIV : 200mV
TIME/DIV : 500ns
level : 1.3
±
0.3 Vp-p
oscilloscope
BD board
TP (RF)
TP (VC)
+
–
symmetry
A
B
Within 3
±
1 Vp-p
oscilloscope
BD board
TP (TE)
TP (VC)
+
–
E-F Balance (Traverse) Check
Procedure :
1. Connect oscilloscpe to test point TP (TEO) on BD board.
2. Turned Power switch on. Press FUNCTION button to select
CD.
3. Put disc (YEDS-18) in to play the number five track.
4. Press the
p
button, ENTER/NEXT button and
^
button
simultaneously several times until the ‘’SHUFFLE” on the
fluorescent display tube blinks.
(The sledding servo is turned OFF.)
5. Check the level B of the oscilliscope’s waveform and the A (DC
voltage) of the center of the Traverse waveform.
Confirm the following :
A/B x 100 = less than
±
7%
Traverse waveform
0V
level : 500 mV
±
100 mVp-p
A (DC voltage)
Center of the waveform
B
6. Press the
p
button, ENTER/NEXT button and
^
button
simultaneously several times until the ‘’SHUFFLE” on the
fluorescent display tube goes off. (The tracking servo and
sledding servo are turned ON.) Confirm the C (DC voltage) is
almost equal to the A (DC voltage) is step 5.
Traverse waveform
0V
C (DC
voltage)
Sled servo
OFF
Sled servo
ON
Adjustment Location :
[ BD BOARD ] — SIDE A —
TP (RF)
TP
(FOK)
IC101
TP
(VC)
TP
(GND)
TP
(TEO)
TP
(FEO)
IC103
IC102
IC102
CN101
oscilloscope
BD board
TP (FEO)
TP (VC)
+
–
SECTION 7
DIAGRAMS
7-1. CIRCUIT BOARDS LOCATION
SENSOR board
CONNECTOR board
BD board
MOTOR (SLIDE) board
MOTOR (TURN) board
– 20 –
POWER board
CONT COM board
AUDIO board
LEAF SW board
TRANSFORMER board
MAIN board
CD-SW board
MIC board
PANEL board
HP board
ENCAPSULATED
COMPONENT (GRX8/R800)
TCB board (RX88/RX99)
DECO board
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