Panasonic JU-475-4, Руководство по обслуживанию

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7. PREVENTIVE MAINTENANCE
No preventive maintenance is necessary fo r any FDD under normal conditions.
However if adjustments are necessary, the procedures in this manual must be follow ed.
• Adjustments (Refer to Table 8-1)
(1) Make a read/w rite head radial adjustment at the specified track. (Sides 0,1)
(2) Make an index burst adjustm ent a t the specified track. (Sides 0,1)
(3) Make an azim uth measurement a t the specified track. (Sides 0,1)
CAUTION
Do not w rite when using alignm ent diskette. Check th a t w rite protect sensor is properly operating
w ith a data diskette.
Note: Section9 describes the adjustment procedure in detail.
8. SPECIFICATIONS
Table 8-1 Specifications
• MINI (a) type
Drive m o tor is dual speed type. (300 rpm o 360 rpm)
Item
Parameter
JU - 475 - 4AEG
M lN U a) • mode MAXI - m ode
TRACK
VALUE TRACK
v a l u e
1
Index period 32 2ÖÖ ± 3.0ms 32 166.7 ± 3.4rrts
2
O utp u t level
79 18QmV o r m ore 79 IBOmVor more
3 M odulation
00
79
20% or less
OO
79
20% o r less
4 Resolution .... 79
60
% o r more
...........7 9 ...........
60% o r more
5 Radial A liqnm ent
32
±
70%
— —
6 A zim uth
'"""""""± "1 ? ........." i i i i l l l l l l
7
Index burst
68 250
±
I50us
8
Track 0
From track 0 to
track 2 and back
Q ,6xVrc
TH £ S.9m$
8 !!!ll!l!l:|l!i8 !!!lll!ll
—
9 Asymmetry
79 < 500ns 79 < 350ns
10 Head load tim e
00
79
< 50ms —
• MINI (ß) type
Drive m o to r is fixed speed type. (360 rpm)
Item Parameter
JU *475»4A<36
M IN I {ß) - mode MAXI • mode
''
t r a c k
''' '""" '''''''''
v a l u e
'''..... TRACK VALUE
1 Index period
32 166.7 ± 3.4ms —
—
2 O utp u t level
79 18QmV or more 79 180 mV or more
3 M odulation
00
79
20% or less
00
79
20% or less
4
Resolution 79
60% or more 79
60% o r more
5 Radial A liqnm ent
32
t
70%
—*
—
6 A zim uth 68 ± 18'
— —
7
Index burst
68 208 + 125us
—
8 Track 0
From track 0 to
tra c k 2 and back
0.6xV cc
TH S $+9ms
—
9 Asymmetry ' " " ' "79 ..........
' ' < 500ns...... ........
79
............ ....... < 350ns
10 Head load tim e
'00
79
<
50ms
—
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6
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