Fostex CR200 Service Manual page 30

CR200
4.3.13 ACT Offset Adjustment
• Objective
• Symptom when out of adjustment
• Measurement instrument connections Oscilloscope to CN5021, Pin-1 (ACT ERR) (SERVO UCOM BOARD assy)
• Disc
• Player state
• Adjustment location
[ Procedures ]
(1) Move the pickup to midway across the disc (R = 35mm) with the MANUAL / TRACK SEARCH FWD or REV keys.
(2) Press the FINALIZE key and the PLAY key in the order to close the focus servo and then the spindle servo.
(3) Adjust VR1 (ACT. OFS) so that the DC voltage at CN5021 (TP00), Pin 1 (ACT ERR) is 0
4.3.14 ACT Gain Adjustment
• Objective
• Symptom when out of adjustment
• Measurement instrument connections Oscilloscope to CN5021, Pin-1 (ACT ERR) (SERVO UCOM BOARD assy)
• Disc
• Player state
• Adjustment location
[ Procedures ]
(1) Move the pickup to midway across the disc (R = 35mm) with the MANUAL / TRACK SEARCH FWD or REV keys.
(2) Press the FINALIZE key and the PLAY key in the order to close the focus servo and then the spindle servo.
(3) Press the WRITE key to light up the WRITE KEY LED, and short-circuit the Pin-2 and Pin-3 of CN5021.
Adjust VR10 (ACT. GAIN) so that the DC voltage at CN5021 (TP00), Pin 1 (ACT ERR) is Ð380 ± 20mV.
Note : If the great offset is observed, perform the adjustments in the section 4.3.13 and 4.3.142.
30
To optimize the DC offset voltage of the actuator servo.
The unit does not pause, track search is impossible, tracks are skipped.
[ Settings ]: 5 mV/div, 5 mS/div., DC mode
TCD-785
Test mode, focus and spindle servos: closed, tracking servo: open
VR1 (ACT. OFS) (HEAD BOARD assy)
To optimize the actuator servo gain.
The unit does not pause, track search is impossible, tracks are skipped.
[ Settings ]: 10 mV/div., 5 mS/div., DC mode
TCD-785
Test mode, focus and spindle servos: closed, tracking servo: open
VR10 (ACT. GAIN) (HEAD BOARD assy)
20mV.