9. ADJUSTMENTS
AND
VERIFICATIONS
9.1
Motor
Speed Verification (Index Period)
(1) Insert a diskette, run
the
motor, and clamp. Refer
to
the index period column
of
Table
8.1
for
the
applicable model.
(2) Step
to
the
specified track.
(3) Connect a frequency counter
to
the
INDEX
signal.
Index {No. 8 Pin
of
CMOSffTL Adaptor)
(4)
Check
that
the
frequency counter readings meet
the
specifications in
the
table.
9.2
Write
Protect Verification
(1) Check
that
the
exerciser's
write
protect lamp goes on and
off
as
a media
is
inserted and removed
as
specified
in
the
table below.
Media
with
write
protect hole open
Media
with
write
protect hole closed
9.3 Head
Output
Verification
ON
(Write protected)
OFF
(Not
write
protected)
Use
a new diskette
if
possible
to
identify
head
failure
for
this check.
(1) Insert a good diskette.
(2)
Run
the
motor.
(3) Step
to
the
track specified in
the
output
level column
of
Table 8.1.
(4) Connect
the
oscilloscope probe
as
specified below.
CH1
T1
CH2
T2
EXT:
Index (No. 8 Pin
of
CMOSITTLAdaptor)
Invert channel 2 and select
the
Add mode.
Set vertical deflection
to
10
mV/division and horizontal deflection
to
20
ms/division.
(5)
Write
2F
(all ones)
on
the
entire circumference.
(In
case
of
a double-sided
FDD,
repeat
it
on sides 0 and 1 using
SIDE
SELECT.)
(6)
Check
that
the
average
output
level meets
the
specifications
of
Table 8.1.
V average=
Vmax+Vmin
]
2
If
it
does
not
meet
the
specifications, refer
to
Item 7
of
the Trouble Analysis Table.
9.4
Output
Modulation
Verification
Modulation:
M
is
calculated by the
following
formula.
M(%)=
Vmax-Vm~n
Vmax+Vmtn
x 100 using
the
value obtained
in
9.3, and check
that
the
calculated value
meets
the
specifications
of
Table 8.1.
Minimum Voltage Value: Vmin
~~~~~~~~~~~t---t--T-~
tt.
Maximum Voltage Value: Vmax
Average Voltage
-
-
Fig.
9.1
Modulation
-7-
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