Focus Servo Loop Gain; Focus Servo Loop Gain Adjustment - Sony CDU31A Series Service Manual

S-1-4 Focus Servo Loop Gain
a. Connect Frequency Response analyzer and S/A
Attachment Tool to PS/2 system. (Refer to Fig. 5-1-4)
b. Connect the BNC (one end) cable between FE-2
terminal on fi?Cture CDl and FB IN terminal on SIA
Attachment Tool.
c. Connect another BNC (one end) cable between FE-3
terminal on fixture CDl and ERR IN/DIS out terminal
on SIA Attachment Tool.
d. Tum on the power of the analyzer and S/A Attachment
Tool.
e. Set mode of Frequency Response Analyzer as below.
(Refer to Instruction Manual for detail)
Disturbance frequency l kHz
Disturbance amplitude
Integration time
Analysis mode
Float
IOOmV rms
5 times
(both CH)
CH-l/CH-2
GND
f. Set the SI switch of SIA Attachment Tool to on.
g. Select Play TNO by hitting the IFlOj key in Test Mode
menu.
h. Select No. 18 with arrow key, then hit !Enter! key.
1.
Hit !Measure! button on the analyzer to start the
measurement of Focus Servo Loop Gain.
j.
After for a while, check if the Focus Servo Loop Gain
indicated on the analyzer, meets specification of 0
±
O.SdB .
. k. If the Focus Servo Loop Gain does not meet the
specification, adjust RV103 so that its gain is within
0
±
0.2dB ·during above measuring.
5-4
BNC (one end)
Cable
BNC Cable (Application)
Frequency Response Analyzer
Fig. 5-1-4 Focus Servo Loop Gain Adjustment