Sony CDP-EX77 / CDP-EX770 / DHC-EX77MD / DHC-MD77 / MHC-EX66 Service Manual ▷ View online
– 13 –
BD BOARD
OPTICAL PICK-UP, SLED MOTOR
4 flat wire
(CN101)
5 screw
(BVTP 2.6
×
8)
6 Removal
the four solders.
7 BD board
1 two screws
(PTPWH M2.6
×
6)
1 two screws
(PTPWH M2.6
×
6)
2 optical pick-up
section
3 two springs
limit switch
3 two springs
1 claw
2 sled shaft
3 optical pick-up
4 two screws
(P 2
×
3)
5 sled motor
– 14 –
SECTION 4
ELECTRICAL ADJUSTMENTS
+
–
–
BD board
TP (TEO)
TP (VC)
oscilloscope
(DC range)
+
–
–
BD board
TP (RF)
TP (VC)
oscilloscope
5. Confirm that the oscilloscope waveform (S-curve) is symmetri-
cal between A and B. And confirm peak to peak level within
2.4 ± 0.7 Vp-p.
2.4 ± 0.7 Vp-p.
S-curve waveform
6. After check, remove the lead wire connected in step 2.
Note:
Note:
•
Try to measure several times to make sure that the ratio
of A : B or B : A is more than 10 : 7.
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.
brightness to obtain best waveform.
RF Level Check
Connection:
Connection:
Procedure:
1. Connect the oscilloscope to TP (RF) and TP (VC) on BD board.
2. Turned power switch on. (stop mode)
3. Put disc (YEDS-18) in and press the
1. Connect the oscilloscope to TP (RF) and TP (VC) on BD board.
2. Turned power switch on. (stop mode)
3. Put disc (YEDS-18) in and press the
^ button.
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
E-F Balance (Traverse) Check
Connection:
Connection:
Procedure:
1. Connect the TP501 (ADJ) and Ground with lead wire. (on the
1. Connect the TP501 (ADJ) and Ground with lead wire. (on the
display board)
2. Connect the oscilloscope to TP (TEO) and TP (VC) on BD
board.
3. Turned power switch on.
4. Put disc (YEDS-18) in and press the
4. Put disc (YEDS-18) in and press the
^ button.
5. Press the TIME button. (Tracking servo and sled servo are
turned off.)
6. Confirm that the oscilloscope waveform is symmetrical on the
top and bottom in relation to 0 Vdc, and check this level.
A
B
symmetry
within 2.4 ± 0.7 Vp-p
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
(with the 10 : 1 probe
in use)
TIME/DIV: 500 ns
(with the 10 : 1 probe
in use)
level: 1.3 ± 0.3 Vp-p
Notes:
1. CD Block basically constructed to operated without adjust-
1. CD Block basically constructed to operated without adjust-
ment.
Therefore, check eaech item in order given.
Therefore, check eaech item in order given.
2. Use YEDS-18 disc (Part No.: 3-702-101-01) unless otherwise
indicated.
3. Use the oscilloscope with more than 10 M
Ω
impedance.
4. Clean an object lens by an applicator with neutral detergent
when the signal level is low than specified value with the fol-
lowing checks.
lowing checks.
5. Adjust the focus bias adjustment when optical pick-up is re-
placed.
Focus Bias Adjustment
This adjustment is to be done when the optical pick-up is replaced.
This adjustment is to be done when the optical pick-up is replaced.
Condition: This adjustment is performed with the set placed hori-
zontally.
Connection:
+
–
–
BD board
TP (FEO)
TP (VC)
oscilloscope
Procedure:
1. Connect the oscilloscope to TP (FEO) and TP (VC) on BD
1. Connect the oscilloscope to TP (FEO) and TP (VC) on BD
board.
2. Connect the TP (FOK) and TP (GND) with lead wire.
3. Turned power switch on.
4. Put disc (YEDS-18) in and turned power switch on again and
3. Turned 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.)
table is moving in and out.)
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
(with the 10 : 1 probe
in use)
TIME/DIV: 500 ns
(with the 10 : 1 probe
in use)
1.3 ± 0.3 Vp-p
Adjustment Procedure:
1. Connect the oscilloscope to TP (RF) and TP (VC) on BD board.
2. Turned power switch on. (stop mode)
3. Put disc (YEDS-18) in and press the
1. Connect the oscilloscope to TP (RF) and TP (VC) on BD board.
2. Turned power switch on. (stop mode)
3. Put disc (YEDS-18) in and press the
^ button.
4. Adjust RV101 so that the oscilloscope waveform is as shown
in the figure below (eye pattern).
A good eye pattern means that the diamond shape (≈) in the
center of the waveform can be clearly distinguished.
A good eye pattern means that the diamond shape (≈) in the
center of the waveform can be clearly distinguished.
5. After adjustment, check the RF signal level.
•
RF signal reference waveform (eye pattern)
When observing the eye pattern, set the oscilloscope for AC
range and raise vertical sensitivity.
range and raise vertical sensitivity.
S-Curve Check
Connection:
Connection:
+
–
–
BD board
TP (RF)
TP (VC)
oscilloscope
(AC range)
– 15 –
A
B
Traverse waveform
level: 300 ± 100 mVp-p
7. After check, remove the lead wire connected in step 1.
Focus/Tracking Gain Adjustment (RV102, RV103)
This gain has a margin, so even if it is slightly off. There is no
problem.
Therefore, do not perform, this adjustment.
Please note that it should be fixed to mechanical center position
when you moved and do not know original position.
This gain has a margin, so even if it is slightly off. There is no
problem.
Therefore, do not perform, this adjustment.
Please note that it should be fixed to mechanical center position
when you moved and do not know original position.
Adjustment Location :
[BD BOARD]
– Side B –
specified value:
2 (A+B)
A-B
×
100 = less than ± 7%
• A+B = 300 ± 100 mVp-p
•
[DISPLAY BOARD]
– Conductor Side –
RF
TEI
FEO
FOK
IC102
PCK
FEI
RV101
RV103
TEO
VC
RV102
IC101
GND
IC104
IC501
TP501
(ADJ)
– 16 –
SECTION 5
DIAGRAMS
•
Circuit Boards Location
PANEL
board
board
DISPLAY board
RELAY board
MAIN board
LOADING board
BD board
TABLE board
SENSOR board
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