Sharp MD-R3H Service Manual page 28

MD-R3H
Mechanism Adjustment
1. Optical pickup grating inspecting method
42 pin of IC 1101
GND (TP1131)
100K
26 pin of IC 1101
EOUT (TP1133)
470p
470p
25 pin of IC 1101
FOUT (TP1132) 100K
Figure 28-1 Optical Pickup Grating Deviation
Measuring Method
After the automatic adjustment is performed in the AUTO
mode (test mode) with the aid of high refection MD disc
("COMPLATE" is displayed), the Lissajous's waveform (x-y) is
adjusted.
1. Slightly loosen the 3 screws of spindle moto, and maken an
adjustment, observing the Lissajous's waveform.
2. After adjustment tighten the screw in arder of 1 , 2 , 3 .
2. Jitter adjustment and checking method
1pin of IC 1201 (TP1274)
EFMMON
88 pin of IC 1201 (TP1275)
GND
Figure 28-3 Jitter connection diagram
After performing automatic adjustment in AUTO mode of
TEST mode using the low reflection MD disc, check this jitter
in pit continuous playback and groove continuous playback
mode.
5P extension flat cable
QCNWK0109AFZZ
CNP1601(Bottom side)
CNP1602
CNP1603
CNP1604(Bottom side)
6P-2P extension connector
QCNWK0107AFZZ
OSILLOSCOPE
GND CH1 CH2
b
X Y
LISSAJOUS'S WAVEFORM
Less thana:b = 3:1
jitter Meter
CNP1252
From mecha-
nism switch
PWB
CNP1101
28Pextension flat cable
MD Main PWB
QCNWK0108AFZZ
a
Spindle Motor
Adjusting hole
1
2P extension connector
QCNWK0059AFZZ
From
motor
Extension PWB for service
(RUNTK0457AFZZ)
Fit the extension PWB for service to the mechanism
Figure 28-4
– 28 –
1
3
2
3
Spindle motor
Check the Lissajou's waveform,
shifting the mounting position with
a screwdriver (to be fitted into the
disc motor adjusting hole).
adjusting
hole
2
Figure 28-2
From Magnetic Head
From Optical
Pickup Unit