22
CX-JN331/JPK331
reverse
forward
3. Mode: Playback
4. After the adjustments, apply suitable locking compound to
the pats adjusted.
Adjustment Location: Playback Head (Deck A).
Record/Playback/Erase Head (Deck B).
MAIN
baord
CN309
set
test tape
P-4-A100
(10 kHz, –10 dB)
pin
3
oscilloscope
L-CH
R-CH
V
H
waveform of oscilloscope
in phase 45
°
90
°
135
°
180
°
good
wrong
pin
4
pin
5
L
R
CD SECTION
Note:
1.
CD Block is basically designed to operate without adjustment. Therefore,
check each item in order given.
2.
Use YEDS-18 (3-702-101-01) unless otherwise indicated.
3.
Use an oscilloscope with more than 10MW 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.
S-CURVE CHECK
Procedure :
1. Connect an oscilloscope to TP (FE) and TP (VC) on the CD
board.
2. Press the
I/
1
button to turn the power ON.
3. Load a disc (YEDS-18) and actuate the focus search. (In
consequence of open and close the disc tray, actuate the focus
search)
4. Confirm that the oscilloscope waveform (S-curve) is
symmetrical between A and B. And confirm peak to peak level
within 3
±
0.5 Vp-p.
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
brightness to obtain best waveform.
Connecting Location: CD board
RFAC LEVEL CHECK
Procedure :
1. Connect an oscilloscope to TP (RFACO) and TP (VC) on the
CD board.
2. Press the
I/
1
button to turn the power ON.
3. Load a disc (YEDS-18) and playback.
4. Confirm that oscilloscope waveform is clear and check if RFAC
signal level is correct or not.
Note:
Clear RFAC signal waveform means that the shape “
◊
” can be
clearly distinguished at the center of the waveform.
Connecting Location: CD board
CD board
Oscilloscope
TP(FE)
TP(VC)
symmetry
S-curve waveform
within 3
±
0.5 Vp-p
A
B
TP(RFACO)
CD board
oscilloscope
TP(VC)