— 15 —
CD SECTION
Note:
1.
CD Block is basically constructed 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.
RF Level Check
Procedure :
1.
Connect oscilloscope to test point TP (RF) on CD DECODER
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.
Adjustment Location:
[CD DECODER BOARD] — Component side —
CD DECODER
board
oscilloscope
TP (RF)
TP (VC)
VOLT/DIV: 200 mV
TIME/DIV: 500 nS
level: 1.0 Vp-p
+0.3
–0.2
IC702
IC701
J778
J789
TP (VC)
TP
(RF)
CN701
