Cd Section - Sony MXD-D400 Service Manual

MXD-D400

CD SECTION

Note:
1. CD Block is basically designed to operate without adjustment. There-
fore, 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 10MΩ 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
Connection:
BD (CD) board
TP (FE)
TP (VC)
Procedure:
1. Connect oscilloscope to test point TP (FE) and TP (VC) on
BD (CD) board.
2. Turn the power on.
3. Put disc (YEDS-18) in.
4. Enter the test mode, select the BU Test and press
the (CD) knob to display "bdt S CURVED".
l AMS L
5. Press the
l AMS L
and playback starts automatically.
6. Check the oscilloscope waveform (S-curve) is symmetrical
between A and B. And confirm peak to peak level within 3.6 ±
0.5 Vp-p.
[MENU/NO]
7. Press the button to stop playback.
8. Exit from the test mode.
(Refer to the TEST MODE Section)
S-curve waveform
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
brightness to obtain best waveform.
Check Location: BD (CD) board (see page 45)
RF Level Check
Connection:
BD (CD) board
TP (RFDC)
TP (VC)
Procedure:
1. Connect oscilloscope to test point TP (RFDC) and TP (VC) on
BD (CD) board.
2. Turn ON the power.
3. Put disc (YEDS-18) in to play the number five track.
4. Confirm that oscilloscope waveform is clear and check RF sig-
nal level is correct or not.
44
oscilloscope
(DC range)
+
–
(CD) knob. "LD AL" is displayed
symmetry
A
within 3.6 ± 0.5 Vp-p
B
oscilloscope
(AC range)
+
–
Note: A clear RF signal waveform means that the shape "◊" can be clearly
distinguished at the center of the waveform.
RF signal waveform
Checking Location: BD (CD) board (see page 45)
E-F Balance (1 Track Jump) Check
Connection:
BD (CD) board
TP (TE)
TP (VC)
Procedure:
1. Connect oscilloscope to test point TP (TE) and TP (VC) on
BD (CD) board.
2. Press the / button to turn the power on.
?
1
3. Put disc (YEDS-18) in to play the number five track.
4. Enter the service mode, press the
ON" is displayed. (The tracking servo and the sledding servo
are turned OFF)
5. Rotate RV101 on BD (CD) board to adjust A (DC voltage) of
the center of the oscilloscope waveform becomes 0 V.
6. Enter the service mode, press the
ON" is displayed (The tracking servo and the sledding servo
are turned OFF), confirm A (DC voltage) at that time is 0 V.
Traverse Waveform
0V
level=1.1 ± 0.6Vp-p
Checking Location: BD (CD) board (see page 45)
Adjustment after CD Base Unit (BU-30BBD61B) is Replaced
Perform the "E-F Balance (1 track jump) check".
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
(normal speed)
level: 1.1 ± 0.3 Vp-p
oscilloscope
(DC range)
+
–
[INPUT]
button until "TRV
[INPUT]
button until "TRV
Center of
waveform
B
A (DC voltage)
Symmetry