Sony CFD-21 - Focus Bias Adjustment

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 test mode. (See page 14)
Press the PP and I¢q 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.
6. Release test mode after adjustment is completed.
ARWN Ee
A
OV A=B
B
VOLT/DIV: 1 V
TIME/DIV: 1 ms
{CD MAIN BOARD] (conductor side)
oscilloscope
(DC range)
oscilloscope
(DC range)
Focus Bias Adjustment
oscilloscope
(DC range)
Focus Gain Adjustment
CFD-20/30
Focus Bias Adjustment
This adjustment is to be done when the optical block replaced.
Adjustment Procedure:
1. Connect the oscilloscope between IC701 pins @) and @).
2. Put the set into test mode. (See page 14)
3. Press the PPI and Iq 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.)
4. Insert disc (YEDS-18) and press ® key.
5. Adjust RV705 so that the oscilloscope waveform os 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.
6. Release test mode after adjustment is completed.
e@ RF signal reference waveform (eye pattern)
DQ KY)
Nit
VOLT/DIV: 0.2 V
TIME/DIV: 500 ns
S2
0.8-1.5 Vp-p
V4 )
AA
URI
NYY
When observing the eye pattern, set the oscilloscope for AC range
and raise vertical sensivity.
Adjustment Location : CD MAIN board
(component side)
Rv704 VCO Adjustment
RvV703_ Tracking Gain Adjustment
Rv702 Focus Gain Adjustment
RV705
RV701
Focus Bias Adjustment
E. F Balance Adjustment
£. F Balance Adjustment
Tracking Gain Adjustment