– 14 –
Procedure:
1. Connect oscilloscope to test point TP (RF).
2. Turned Power switch on.
3. Put disc (YEDS-18) in and playback.
4. Adjust RV101 so that the waveform is clear.
(Clear RF signal waveform means that the shape “
◊
” can be
clearly distinguished at the center of the waveform.)
5. After adjustment, check the RF signal level.
• RF signal
VOLT/DIV: 200 mV
TIME/DIV: 500 nS
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 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 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
VOLT/DIV: 200 mV
TIME/DIV: 500 nS
CD SECTION
Note:
1. CD Block is basically designed 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 lens cleaning liquid
when the signal level is low than specified value with the fol-
lowing checks.
5. Adjust the focus bias adjustment when optical block is replaced.
Focus Bias Adjustment
Perform this adjustment when the optical pick-up has been replaced
or repaired.
–
+
oscilloscope
BD (CD) board
TP (RF)
TP (VC)
level : 1.3
±
0.3 Vp-p
–
+
oscilloscope
BD (CD) board
TP (FEO)
TP (VC)
symmetry
A
B
within 2.4
±
0.7 Vp-p
–
+
oscilloscope
BD (CD) board
TP (RF)
TP (VC)
SECTION 6
ELECTRICAL ADJUSTMENTS
level : 1.3
±
0.3 Vp-p
Summary of Contents for HCD-SD1
Page 27: ...HCD SD1 35 36 7 10 SCHEMATIC DIAGRAM PANEL SECTION Page 30 Page 30 ...
Page 29: ...HCD SD1 7 12 SCHEMATIC DIAGRAM AMP SECTION 39 40 Page 47 48 Page 43 Page 28 ...
Page 31: ...HCD SD1 7 14 SCHEMATIC DIAGRAM CONNECTOR SECTION 43 44 Page 30 Page 29 Page 40 Page 33 ...
Page 33: ...HCD SD1 7 16 SCHEMATIC DIAGRAM REG SECTION 47 48 Page 40 Page 29 Page 29 Page 33 ...
