Pioneer PDR-04 - Manual (Page 56)

PDR-04
6.2.7 Fine Skew Adjustment Adjustment 1
• Objective
• Symptom when out
of adjustment
To adjust the angle of the pickup relative to the disc so that the laser beams are shone straight
down into the disc for the best read out of the RF signals.
Sound broken, some discs can be played but not others.
• Measurement instru­
ment connections
Connect the oscilloscope to
CN204 (TP201), Pin 1 (RF)
(SERVO UCOM BOARD assy)
[Settings] 20 mV/div.
200 nS/div.
AC mode
• Player state
• Adjustment
location
• Disc
Test mode, play
Pickup radial adjustment screw and
tangential adjustment screw
STD-903
[ Procedure ]
(1) Move the pickup to the position where the radial/tangential adjustment screws will be seen with the MANUAL / TRACK
SEARCH FWD ►► or REV ◄◄ keys so that the radial/tangential adjustment screws can be adjusted.
(2) Press the FINALIZE key, then the PLAY ► key to the PAUSE
II
key in that order to close the respective servos and put the
player Into play mode.
(3) First, adjust the radial adjustment screw with the hexagonal screwdriver (1.27 mm) so that the eye pattern (the diamond
shape at the center of the RF signal) can be seen the most clearly.
(4) Next, adjust the tangential adjustment screw with the hexagonal screwdriver so that the eye pattern can be seen the most
clearly. (Fig. 5).
(5) Adjust in the order of the radial adjustment screw and the tangential screw again, so that the eye pattern can be seen the
most clearly. As necessary, adjust the two screws alternately so that the eye pattern can be seen the most clearly.
(6) After the adjustment, remove the float screw, turn over the servo mechanism assembly, then stabilize the radial adjustment
screw and the tangential adjustment screw with an adhesive.
Stabilize each screw
Hexagonal
screwdriver
(Front side)
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