Fostex CR200 Service Manual page 17

4.2 Adjustment 1
4.2.1 Playback Power Adjustment
• Objective
• Symptom when out of adjustment
• Measurement instrument connections Multimeter to CN104, Pin-7 (PWAJT) (HEAD BOARD assy)
• Disc
• Player state
• Adjustment location
CAUTION:
(a) Perform this adjustment more than 5 minutes after starting up the test mode.
This adjustment cannot be performed accurately if disc is inserted. Be sure to remove disc first before adjustments.
(b)
(c) If the specified voltage is not obtained by turning VR103, the pickup assy might be defective. Also be careful not to get
the pickup lens dirty.
[ Procedures ]
When adjusting with the multimeter.
•
(1) Lights up the playback laser diode using the DIGITAL SYNCHRO key.
(2) Adjust the voltage value of Pin-7 (PWAJT) of CN104 (TP1) to the voltage value (PB PW voltage ± 5mV) displayed on
the pickup flexible cable using VR103 (PB PW).
Reference: When adjusting with the optical power meter.
•
(1) Move the pickup to the outer edge of the disc with the MANUAL / TRACK SEARCH FWD key.
Lights up the playback laser diode by the DIGITAL SYNCHRO key.
(2)
(3) Shine the light discharged from the objective lens in the pickup on the light power meter sensor. Adjust VR103 (PB.
PW) so that the playback laser diode output is an average 0.65 mW ± 0.05mW.
(Wavelength 790nm, Average mode)
* Recording on the disc is not possible in test mode.
DANGER - LASER RADIATION WHEN OPEN.
AVOID DIRECT EXPOSURE TO BEAM.
To optimize the playback power of the laser diode.
Does not start playing, track search is impossible, tracks are skipped.
GND probe can be connected to CN104, Pin-4 (AGND).
None needed
Test mode, Playback laser diode ON
VR103 (PB. PW) (HEAD BOARD assy)
Fig. 9
P : Playback power
R : Recording power
CR200
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