— 23 —
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 neutral detergent when the
signal level is low than specified value with the following checks.
5. Adjust the focus bias adjustment when optical block is replaced.
Focus Bias check
Procedure:
1. Connect oscilloscope to test point TP (RF). (GND terminal :
VC)
2. Turned Power switch on.
3. Put disc (YEDS-18) in and playback.
4. Confirm that the shape “
≈
” can be clearly distinguished at the
center of the waveform and check the RF signal level.
• RF signal
S Curve Check
Procedure:
1. Connect oscilloscope to test point TP (FEO).
2. Connect between test point TP (FOK) and GND 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
between A and B. And confirm peak to peak level within 3±1
Vp-p.
S-curve waveform
6. After check, remove the lead wire connected in step 2.
Notes:
• 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.
RF Level Check
• RF signal
+
–
BD board
TP (RF)
VC
oscilloscope
(DC range)
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
level:
1.3
±
0.3Vp-p
+
–
BD board
TP (FEO)
TP (VC)
oscilloscope
A
B
symmetry
within 3
±
1 Vp-p
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 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.
+
–
BD board
TP (RF)
TP (VC)
oscilloscope
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
level:
1.3
±
0.3Vp-p
Summary of Contents for HCD-D390 - Compact Audio And Video System
Page 7: ... 7 This section is extracted from instruction manual ...
Page 33: ...HCD D390 D790 G5500 XB33 XB44 XB50 XB60 41 42 6 6 SCHEMATIC DIAGRAM CD MOTOR SECTION ...
Page 39: ...HCD D390 D790 G5500 XB33 XB44 XB50 XB60 6 12 SCHEMATIC DIAGRAM DECK SECTION 51 52 ...
Page 40: ...HCD D390 D790 G5500 XB33 XB44 XB50 XB60 6 13 SCHEMATIC DIAGRAM SWITCH SECTION 53 54 ...
Page 43: ...HCD D390 D790 G5500 XB33 XB44 XB50 XB60 57 58 6 16 SCHEMATIC DIAGRAM HEADPHONE MIC SECTION ...
