Fostex CR200 Service Manual page 23

4.2.7 Fine Skew Adjustment
• Objective
• Symptom when out of adjustment
• Measurement instrument connections Oscilloscope to CN204, Pin-1 (RF) (SERVO UCOM BOARD assy)
• Disc
• Player state
• Adjustment location
[ Procedures ]
(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, the PLAY key and the PAUSE key in the 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 and the amplitude is at maximum..
(4) Next, adjust the tangential adjustment screw with the hexagonal screwdriver so that the eye pattern can be seen the most
clearly. (Fig. 17).
(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.
After the adjustment, remove the float screw, turn over the servo mechanism assembly, then secure the radial adjustment
(6) screw and the tangential adjustment screw with loc-tite.
(Front side)
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 is cracking, some discs can be played but not others..
GND probe can be connected to CN204, Pin-4 (AGND).
[ Settings ]: 20 mV/div., 200 nS/div., AC mode
TCD-785
Test mode, play
Pickup radial adjustment screw and tangential adjustment screw
Stabilize each screw
with an adhesive.
Radial
adjustment
screw
Tangential
adjustment
screw
Fig. 16
Hexagonal
screwdriver
(Rear side)
CR200
23