Fostex CR200 Service Manual page 28

CR200
4.3.9 Coarse Focus Offset 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) Press the FINALIZE key and the PLAY key in the order to close the focus servo and then the spindle servo.
(2) Adjust VR105 (FE. OFS) so that the amplitude of RF signal at CN204, Pin-1 (RF) is maximum.
4.3.10 Main and Sub Mix Ratio Adjustment
• Objective
• Symptom when out of adjustment
• Measurement instrument connections Oscilloscope to
• Disc
• Player state
• Adjustment location
[ Procedures ]
(1) Press the FINALIZE key and the PLAY key in the order to close the focus servo and then the spindle servo.
(2) Set the oscilloscope to ADD mode (waveform adding mode of CH1 and CH2) and observe the adding waveform of CH1
and CH2.
(3) Adjust VR110 (MS. MIX) so that the amplitude of waveform becomes minimum.
28
To optimize the DC offset voltage of the focus error amp.
The unit does not focus in and the RF signal is dirty.
GND probe can be connected to CN204, Pin-4 (AGND).
[ Settings ]: 20 mV/div., 2 mS/div., DC mode
TCD-785
Test mode, focus and spindle servos: closed, tracking servo: open
VR105 (FE. OFS) (HEAD BOARD assy)
Out of adjustment
Fig. 18
To mix the gain of the main signal output and sub signal output of the pickup.
The unit does not playback.
CH1: CN104, Pin-1 (STE) (HEAD BOARD assy)
CH2: CN104, Pin-2 (MSTE) (HEAD BOARD assy)
[These connections must be via low pass filters. ]
GND probe can be connected to CN104, Pin-4 (AGND).
[ Settings ]
CH1 : 50 mV/div. AC mode
10 mS/div. ADD mode
CH2 : 100 mV/diV. AC mode
TCD-785
Test mode, focus and spindle servos: closed, tracking servo: open
VR110 (MS. MIX) (HEAD BOARD assy)
Optimum adjustment