Pioneer PDR-04 - Manual (Page 55)

PDR-04
6.2.6 Fine Focus Offset Adjustment Adjustment 1
> Objective
Symptom when out
of adjustment
To optimize the DC offset voltage of the focus servo circuit.
The player does not focus in, sound broken and the RF signal is dirty.
• Measurement instru­
ment connections
Connect the oscilloscope to
CN204(TP201), Pin 1 (RF).
(SERVO UCOM BOARD assy)
[ Settings ] 20 mV/div.
500 nS/div.
AC mode
Player state
• Adjustment
location
• Disc
Test mode, play
VR105 (FE.OFS)
(HEAD BOARD assy)
STD-903
[ Procedure ]
(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, the play ► key, then the PAUSE ll key in that order to close the respective servos and put the
player into play mode.
(3) Adjust VR105 (FE. OFS) so that the 3T waveform at CN204 (TP201), Pin 1 (RF) is maximum.
r V •> 'ft ^ , ft- .ft- y :
Out of adjustment Optimum adjustment
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