6.25.2 SCALE ASSEMBLY INSTALLATION
(1)
Align the hole in the frame
of
the replacement Scale Assembly with the locating
pin
on
the carriage.
CAUTION
WHEN REPLACING THE
SCALE
ASSEMBL
Y
,
ENSURE
THA T
IT
DOES
NOT
CONTACT
THE RETICLE
ASSEMBL
Y.
(2)
Press the Scale Assembly firmly against the carriage so the locating pin is firmly
seated.
(3)
Replace, but do not tighten, the three Allen
head
screws removed in Paragraph
6.25.1,
Step (3).
(4)
Replace the Lamp/Lens Assembly removed in Paragraph 6.25.1, Step (2).
(5)
Disconnect connector
J205
from the Servo PCBA; this removes power from the
linear motor
so
that the .leads
can
be
positioned manually.
(6)
Apply power to the disk drive
and
observe that the SAFE indicator becomes
illuminated. The carriage
can
now be manually extended and retracted.
(7)
Extend the carriage fully toward the disk drive spindle.
(8)
Adjust the Scale Assembly so that the clearance between the reticle and the glass
scale is
0.005 inches at both ends
of
the carriage travel. A 0.005-inch mylar shim
can
be
used for this purpose.
(9)
Connect a
DVM
between
TP20
and
TP1
(ground) on the Servo PCBA. Measure
and
note the voltage.
(10)
Move the carriage back
and
forth over its full stroke; the voltage noted in Step
(9)
should remain constant.
NOTE
If
the voltage obtained in Step [10] varies more than
± 10%, rotate the Scale Assembly about the
pin
until
the
voltage observed over the
full
carriage stroke remains
within
± 10%.
(11)
Tighten the three Allen head screws
on
the Scale Assembly.
(12)
Replace the two heads removed in Paragraph 6.25.1 Step
(1)
by
following the
head
installation procedure detailed in Paragraph 6.22.2.
NOTE
Do
not
replace J205
at
this time.
(13)
Perform the static
and
dynamic positioner procedures given in Paragraphs
6.8 and 6.9, respectively.
6.28
AIR
FILTER
The
filter assembly conSists of two parts, the pre-filter, which is a fine-meshed open-cell
foam material covering the
air
intake area
of
the absolute filter, and the absolute filter.
The
absolute filter consists of a labyrinth of small metallic separators, forming the filter path
between the filter media.
The
absolute filter is encased within a plastic frame for ease
of
handling and to prevent
damage to the internal structure.
Handle the absolute filter by the edges of the plastic framework. Use caution not to
compress the sides or center
of
the filter as puncturing
of
the filtering media could result,
thereby lessening the effectiveness of the filter.
6-89
8300
To Next Page
Loading...