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7. Close the front cover immediately to
prevent the entry of dust and the
contamination of the disk surfaces.
DISK PACK REMOVAL
1. Press (to extinguish) to operator
panel START switch.
2.
Check that disk pack rotation has
stopped completely.
3 •
Iai.se
the front cover.
CAUTION
During maintenance procedures the
read/write heads are
somet~es
manually positioned.
Make certain
that the heads are fully retracted.
4. Place the plastic canister over the
mounted disk pack so that the post
protruding from the center of the disk
pack is received into the canister
handle.
5. Twist the canister handle counterclock-
wise until the disk pack is free of the
spindle.
CAUTION
Avoid abusive contact between the
disk pack and the spindle assembly
6. Lift the canister and the disk pack
clear of the spindle.
7. Close the front cover.
8. Place the bottom dust cover in position
on the disk pack and tighten it.
9. Store the disk pack in a clean cabinet
or on a clean shelf.
HEAD ALIGNMENT CARD (DSFV)
Four LED indicators are provided as monitors
to ensure accurate alignment data is taken.
Their functions are:
Power
Input
- When lighted indicates power is
applied to card (card is fully
inserted in card slot).
- When lighted idnciates amplitude
of alignment signal is below
minimum threshold required to
allow alignment card to operate.
Bad
~-
When lighted indicates short
duration loss of alignment
signal.
Indicator lights when
polarity (Sl) is operated.
A
one-shot maintains light for
four seconds.
83318200
C
Mode
- When lighted indicates switches
S2 (servo-R/W select) or
S3
,(meter sensitivity) are not in
correct position to measure data
head alignment error.
NOTE
Measurement of data head align-
ment error can be taken only when
the power indicator is on and
the other indicators are off.
Three toggle switches are provided.on the
card edge Which perform the follow1ng
functions:
Sl
- Switch changes the polarity of the
alignment signal and is used in
taking measurements of both servo
and data heads as follows:
a) note null meter reading in
P
(normal) position
b)
note null meter reading in
N
(reverse) position
then P-N = alignment position, i.e.,
P~+30
mv,
N=-40 mv(+30)-(-40)=+70 mv
alignment error.
S2
S3
- Switch selects the servo head (S)
as an input to the card on 'the data
head
(R/W)
as an input to the card.
When switch is in S position, mode
indicator will light.
- Switch changes the sensitivity of
the meter circuit (TPX and TPY).
In Xl position, meter readings are
multiplied by 1, in X.l
~ultip~y
meter readinqs by 10.
W1
th
SWl.
tch
in Xl position, mode indicator
lights.
Test points TP-X and TP-Z are connected to
the null meter.
TP-Y is connected to an
oscilloscope to observe the dibit pattern.
,OFF LINE TESTER
The Off Line Tester PN 86073404 permits full
control of the drive seek and read/write
logic without computer intervention.
The tester front panel is illustrated in
Figure
2-2.
Switch functions are defined
in Table
2-2.
PREPARA nON FOR USE
1. Verify that the CPU operating system
permits the drive to be removed from
computer control.
2. Open cabinet rear door.
2-7
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