Sony CX-LDB30 / CX-LDB50 / XR-DB30 / XR-DB50 Service Manual ▷ View online
21
CX-LDB30/LDB50
4. After the adjustments, apply suitable locking compound to
the parts adjusted.
Adjustment Location: Record/Playback/Erase Head
3. Mode: Playback
set
test tape
P-4-A100
(10 kHz, –10 dB)
P-4-A100
(10 kHz, –10 dB)
R-CH
oscilloscope
L-CH
R-CH
V
H
waveform of oscilloscope
in phase 45
°
90
°
135
°
180
°
good
wrong
MAIN board
SPEAKER terminal (J201)
L-CH
SPEAKER terminal (J201)
L-CH
Tape Speed Check
Mode: Playback
Note: Refer to “3-9. Cassette Panel” (see page 11)
adjustment screw
1. Insert the WS-48B into deck.
2. Press the TAPE N button of deck.
3. Confirm that the frequency counter reads 3000
2. Press the TAPE N button of deck.
3. Confirm that the frequency counter reads 3000
± 90 Hz.
Sample Value of Wow and flutter: 0.3% or less W.RMS (JIS)
(WS-48B)
+
–
–
set
test tape
WS-48B
(3 kHz, 0 dB)
WS-48B
(3 kHz, 0 dB)
MAIN board
SPEAKER terminal (J201)
L-CH, R-CH
SPEAKER terminal (J201)
L-CH, R-CH
frequency counter
Record Bias Adjustment
Procedure:
1. Record mode
2. Mode: Playback
i-Bass OFF
BASS 0
TREBLE 0
BASS 0
TREBLE 0
3. Confirm playback the signal recorded in step 1 become
adjustment level as follows.
Adjustment level: Playback output of 315 Hz to playback output
of 10 kHz: 0
± 1.0 dB (0 ± 4.5mV).
attenuator
set
MAIN board
AUX IN (J291)
AUX IN (J291)
1) 315 Hz
2) 10 kHz
2) 10 kHz
50 mV (–23.8 dB)
600
Ω
blank tape
CN-123
CN-123
AF OSC
+
–
–
set
recorded
portion
portion
MAIN board speaker terminal (J201)
level meter
22
CX-LDB30/LDB50
CD SECTION
Note:
1. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
2. Use an oscilloscope with more than 10M
2. Use an oscilloscope with more than 10M
Ω impedance.
3. Clean the object lens by an applicator with neutral detergent
when the signal level is low than specified value with the
following checks.
following checks.
S-curve Check
Connection:
Procedure:
1. Connect an oscilloscope to test point TP (FEO) and TP (VC)
on the BD board.
2. While depressing the CD u button, insert an AC plug.
3. Put the disc (YEDS-18) in and press the x button and actuate
3. Put the disc (YEDS-18) in and press the x button and actuate
the focus search. (actuate the focus search when disc table is
moving in and out)
moving in and out)
4. Check the oscilloscope waveform (S-curve) is symmetrical
between A and B. And confirm peak to peak level within 2
± 1
Vp-p.
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.
Checking Location: BD board (Conductor Side)
RFDC Level Check
Connection:
Procedure:
1. Connect an oscilloscope to test point (RFDCO) and TP (VC)
on the BD board.
2. Turn the power on.
3. Put the disc (YEDS-18) in to playback the number five track.
4. Confirm that oscilloscope waveform is clear and check RFDC
3. Put the disc (YEDS-18) in to playback the number five track.
4. Confirm that oscilloscope waveform is clear and check RFDC
signal level is correct or not.
Note:
A clear RFDC signal waveform means that the shape “
◊” can
be clearly distinguished at the center of the waveform.
Checking Location: BD board (Conductor Side)
RFAC Level Check
Connection:
Procedure:
1. Connect an oscilloscope to test point TP (RFACO) and TP
(VC) on the BD board.
2. Turn the power on.
3. Put the disc (YEDS-18) in to playback the number five track.
4. Confirm that oscilloscope waveform is clear and check RFAC
3. Put the disc (YEDS-18) in to playback the number five track.
4. Confirm that oscilloscope waveform is clear and check RFAC
signal level is correct or not.
Note:
A clear RFAC signal waveform means that the shape “
◊” can
be clearly distinguished at the center of the waveform.
Checking Location: BD board (Conductor Side)
+
–
–
BD board
oscilloscope
TP (FED)
TP (VC)
TP (VC)
S-curve waveform
symmetry
A
B
within 2
±
1 Vp-p
+
–
–
BD board
oscilloscope
TP (RFDCO)
TP (VC)
RFDC signal waveform
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
TIME/DIV: 500 ns
level: 0.6
±
0.15 Vp-p
+
–
–
BD board
oscilloscope
TP (RFACO)
TP (VC)
RFAC signal waveform
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
TIME/DIV: 500 ns
level: 1.0
±
0.4 Vp-p
23
CX-LDB30/LDB50
E-F Balance Adjustment
Connection:
Procedure:
1. Connect an oscilloscpe to test point TP (TEO) and TP (VC)
on the BD board.
2. AC is put in pushing CD u button to enter the CD test
mode.
3. Put the disc (YEDS-18) in to playback the number five track.
4. Press the CD u button. If it plays, press the CD u button
4. Press the CD u button. If it plays, press the CD u button
again. (The tracking servo and the sledding servo are turned
OFF)
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
Confirm the following :
A/B x 100 = less than
±10%
6. Press the CD u button. (The tracking servo and sledding
servo are turned ON)
Rotate RV101 on BD board and adjust the C (DC voltage) is
almost equal to the A (DC voltage) in step 4.
Rotate RV101 on BD board and adjust the C (DC voltage) is
almost equal to the A (DC voltage) in step 4.
7. To exit from this mode, turn the power off.
Notes:
• Always move the optical pick-up to most inside track when exiting
from this mode. Otherwise, a disc will not be unloaded.
• Do not run the sled motor excessively, otherwise the gear can be
chipped.
Checking Location: BD board (Conductor Side)
Checking Location:
– BD BOARD (Conductor Side) –
+
–
–
BD board
oscilloscope
TP (TEO)
TP (VC)
Traverse Waveform
0V
Center of
the waveform
the waveform
B
A (DC
voltage)
voltage)
level: 1.0
±
0.5 Vp-p
Traverse Waveform
0V
Tracking servo
Sled servo
OFF
Tracking servo
Sled servo
ON
C (DC
voltage)
voltage)
IC251
IC301
IC101
IC303
TP
(RFACO)
TP
(VC)
TP
(FEO)
TP
(RFDCO)
TP
(VEO)
24
CX-LDB30/LDB50
For Schematic Diagrams.
Note:
• All capacitors are in
Note:
• All capacitors are in
µ
F unless otherwise noted. (p: pF)
50 WV or less are not indicated except for electrolytics and
tantalums.
tantalums.
• All resistors are in
Ω
and
1
/
4
W or less unless otherwise
specified.
•
f
: internal component.
•
C
: panel designation.
•
A
: B+ Line.
•
B
: B– Line.
• Voltages and waveforms are dc with respect to ground
under no-signal (detuned) conditions.
No mark: FM
No mark: FM
• Voltages are taken with a VOM (Input impedance 10 M
Ω
).
Voltage variations may be noted due to normal production
tolerances.
tolerances.
• Waveforms are taken with a oscilloscope.
Voltage variations may be noted due to normal production
tolerances.
tolerances.
• Circled numbers refer to waveforms.
• Signal path.
F
: TUNER
J
: CD
d
: AUX
E
: PB (TAPE)
a
: REC (TAPE)
• Abbreviation
E51
: Chilean and Peruvian model.
RU
: Russian model.
AUS
: Australian model.
KR
: Korean model.
For Printed Wiring Boards.
Note:
•
Note:
•
X
: parts extracted from the component side.
•
Y
: parts extracted from the conductor side.
•
f
: internal component.
•
: Pattern from the side which enables seeing.
• Indication of transistor.
THIS NOTE IS COMMON FOR PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS.
(In addition to this, the necessary note is printed in each block.)
(In addition to this, the necessary note is printed in each block.)
C
B
These are omitted.
E
Q
B
These are omitted.
C
E
Note: The components identified by mark
0
or dotted
line with mark
0
are critical for safety.
Replace only with part number specified.
Caution:
Pattern face side: Parts on the pattern face side seen from
(Conductor Side)
Pattern face side: Parts on the pattern face side seen from
(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.
B
These are omitted.
C
E
Q
• Circuit Boards Location
SECTION 7
DIAGRAMS
MAIN board
PANEL board
CD EJECT board
JACK board
DRIVER board
PT board
BD board
Ver. 1.2
Click on the first or last page to see other CX-LDB30 / CX-LDB50 / XR-DB30 / XR-DB50 service manuals if exist.