Sony CMT-CNEZ3 Service Manual page 16

HCD-NEZ3/NEZ5
2. Turn the adjustment screw and check output peaks. If the peaks
do not match for L-CH and R-CH, turn the adjustment screw
so that outputs match within 1dB of peak.
within
L-CH
1dB
peak
Output
level
R-CH
peak
Screw
position
L-CH
peak
3. Mode: Playback
test tape
HEAD PHONE board
P-4-A063
PHONES jack
(6.3 kHz, –10 dB)
(J500)
set
waveform of oscilloscope
in phase 45 °
good
4. After the adjustments, apply suitable locking compound to
the pats adjusted.
Adjustment Location: Record/Playback/Erase Head
14
within
1dB
Screw
position
R-CH
peak
oscilloscope
V H
90 ° 135 ° 180 °
wrong
CD SECTION
Note:
1. CD Block is basically constructed to operate without adjustment.
2. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
3. Use an oscilloscope with more than 10 MΩ 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. Check the focus bias check when optical block is replaced.
FOCUS BIAS CHECK
CD board
TP (RFACO)
TP (VC)
Procedure :
1. Connect the oscilloscope to TP (RFACO) and TP (VC) on the
CD board.
2. Insert the disc (YEDS-18). (Part No. : 3-702-101-01)
3. Press the button.
CD u
4. Confirm that the oscilloscope waveform is as shown in the
figure below. (eye pattern)
A good eye pattern means that the diamond shape (◊) in the
center of the waveform can be clearly distinguished.
• RF signal reference waveform (eye pattern)
VOLT/DIV: 0.2 V (with the 10: 1 probe in use.)
TIME/DIV: 500 ns
When observing the eye pattern, set the oscilloscope
for AC range and raise vertical sensitivity.
Checking Location:
– CD BOARD (Conductor Side) –
TP (VC)
oscilloscope
(DC range)
+
–
1.1
0.2 Vp-p
TP
(RFACO)