Focus Bias Adjustment - Sony CFD-50 Service Manual

E-F Balance Adjustment
This adjustment is to be done when the optical block is replaced.
Adjustment Procedure: :
Connect the oscilloscope between IC701 pins @ and @.
Put the set into service mode. (See page 9)
Press the PP] and k4q keys to move the FOP to the center.
Insert disc (YEDS-18) and press } key.
Adjust RV701 so that the oscilloscope traverse waveform is
symmetrical, as shown in the figure below.
Release service mode after adjustment is completed.
A
8
VOLT/DIV: 1V
TIME/OIV: Ims
Adjustment Location: CD main board (conductor side)
RV702 RV701
Focus Bias Adjustment
This adjustment is to be done when the optical block is replaced.
Adjustment Procedure:
Connect the oscilloscope between IC701 pins @ and @.
Put the set into service mode. (See page 9) _ _
Press the PP] and K¢q keys to move the FOP to the center.
(Move the FOP to the music area on the disc to enable easy
visibility of the eye pattern.)
Insert disc (YEDS-18) and press > key.
Adjust RV702 so 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.
Release service mode after adjustment is completed.
RF signal reference waveform (eye pattern)
\RXANA i
Wie i
\\
VOLT/OIV : 0.2V
TIME/OIV : 500ns
0.8 — 1.5 Vp-p
Hii
MA
Way
Wy
ov
When observing the eye patern, set the oscilloscope for AC
range and raise vertical sensitivity.
E-F Balance Adjustment
oscilloscope
(DC range)
ES Focus Bias Adjustment
+
oscilloscope
(DC range)