630D
6.14.8.2 Adjustment Procedure
(100
and
200
tpi)
If circumferential alignment is required, perform the following procedure.
NOTE
If the separation between pulses,
as
measured in Step
(8)
of
Paragraph 6.14.8.1, exceeds
10
",sec,
remove power
from the disk drive and remove the upper two heads.
Check for foreign material
or
burrs on the head seating
surfaces. Replace one
or
both heads
if
a head problem is
suspected. Reinstall heads and perform the radial
alignment procedure.
(1)
Maintain test conditions established in Paragraph 6.14.8.1, Steps
(1)
and
(2).
(2)
Insert a Phillips-head screwdriver into the Circumferential alignment adjusting
screw located under the cartridge receiver toward the right front of the machine
(viewed facing the front of the drive).
NOTE
Rotation
of
the tool in the CCW direction increases the
pulse delay from Index.
(3)
Select
eitrer
head
(0
or
1)
and, while observing the waveform at
TP19,
turn the
adjusting screw
until the first pulse after the falling edge
of
Index (Channel
2)
falls
within the
30
± 5 ",sec specification.
(4)
Select the other head and ensure that the specification detailed in Step
(3)
is met.
A compromise adjustment may
be
required to meet the
30
± 5 ",sec requirement
for both heads.
See
Figure
6-29.
(5)
Turn the Phillips-head screwdriver slightly in the opposite direction
of
the last to
cause the adjusting screw to relax the force on the mechanism
(I.e., mid-range
of
the screw backlash).
(6)
Recheck heads 0 and 1 to verify that the measurement is still within tolerance.
Repeat
Steps
(3), (4),
and
(5)
as
necessary.
6-68
To Next Page
Loading...