Sony HCD-MD515 - Component For Dhcmd515, Service Manual, Page: 29 / 110

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[BD (CD) BOARD] – Side B –
Notes:
1. CD Block basically constructed to operated without adjust-
ment.
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.
CD SECTION
1. S-Curve CHECK
Connection:
Procedure:
1. Connect the oscilloscope to TP (FEO) and TP (VC) on BD
(CD) 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
actuate the focus search. (actuate the focus search when disc
table is moving in and out.)
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.
S-curve waveform
6. After check, remove the lead wire connected in step 2.
Note:
• Try to measure several times to make sure that 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.
2. RF LEVEL CHECK
Connection:
Procedure:
1. Connect the oscilloscope to TP (RF) and TP (VC) on BD (CD)
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
signal 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
3. E-F BALANCE (TRAVERSE) CHECK
Connection:
+
–
BD (CD) board
TP (FEO)
TP (VC)
oscilloscope
A
B
symmetry
+
–
BD (CD) board
TP (RF)
TP (VC)
oscilloscope
+
–
BD (CD) board
TP (TEO)
TP (VC)
oscilloscope
(DC range)
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
(with the 10 : 1 probe
in use)
1.3 ± 0.3 Vp-p
within 2.4 ± 0.7 Vp-p
Procedure:
1. Connect the lead wire to TP607. (on the SUB board)
2. Connect the oscilloscope to TP (TEO) and TP (VC) on BD
(CD) board.
3. Turned power switch on.
4. Select the CD function.
5. Connect the lead wire to ground (from TP607)
6. Put disc (YEDS-18) in and press the
^ button.
7. Press the DISPLAY button. (Tracking servo and sled servo
are turned off.)
8. Confirm that the oscilloscope waveform is symmetrical on the
top and bottom in relation to 0 Vdc, and check this level.
9. Release the lead wire.
4. CONNECTING POINTS
[SUB BOARD] – Conductor Side –
GND
VC
TEO
FEO
IC103
IC101
FOK
RF
IC102
IC500
IC600
TP607
CN600
CN601