6.14.2.2 Cylinder
005
(100
tpi), Cylinder010
(200
tpi)
For
100
tpi
CE
packs, cylinder
005
is used
for
circumferential adjustment of the upper
magnetic transducer; for
200
tpi, cylinder
010
is used for this adjustment. The cylinder has
a single flux transition marker recorded approximately
180 degrees from the center line of
the index notch. To assist in identifying this marker, a burst
of
flux transitions occurs
10
fJ-Sec
after the marker.
6.14.3
CE
CARTRIDGE STABILIZATION
Prior to attempting alignment, the
CE
cartridge must
be
conditioned in the same
environment in which the disk drive (to
be
aligned) is located. This conditioning must not
be
less than 2 hours.
In
addition to this stabilization period, the
CE
cartridge must
be
operated for at least
30
minutes in the disk drive with the disk drive in the
Run
condition.
This
allows the cartridge to reach the proper temperature
just
prior to performing the
alignment.
6.14.4
TEST
CONFIGURATION - ALL MODELS
The following procedure is used to establish the test configuration for
CE
alignment
of
both top and front loading disk drives.
(1)
Remove the cover from the disk drive and open the circuit boards to their fully
extended positions.
(2)
If installed, remove the
I/O
cable and the terminator PCBA from interface
connectors
J1
01
and
J1
02
on the Logic PCBA.
(3)
Connect a disk exerciser without read/write capabilities to one of the interface
connectors,
J101
or
J1
02.
(4)
Set the upper platter Write Protect switch to the
ON
position.
(5)
Connect the disk drive to the
ac
power source and set the
ON
/ OFF switch to the
ON
position.
(6)
When the SAFE indicator becomes illuminated, insert the speCial
CE
disk
cartridge into the machine.
(7)
Depress the RUN/STOP switch once and allow the disk drive to come READY.
Allow
the disk drive to warm up for at least
30
minutes before proceeding.
(8)
Disconnect the emergency unload capacitor connector
P206
from the Servo
PCBA, thereby de-activating the emergency unload system. If the disk speed
slows noticeably due to the loss of ac power or other malfunction, the heads
must
be
manually unloaded by the operator.
NOTE
It
is the responsibility
of
the person performing the
CE
alignment to perform the emergency unload function when
P206
is disconnected.
(9)
A dual trace oscilloscope having a
50
MHz vertical bandwidth or
greater is required to perform
CE
alignment procedures.
NOTE
Depending on the type
of
oscilloscope utilized and its
grounding arrangement,
it
may
be
necessary
to
use a
differential measurement
of
the Read/Write
PCBA
signal in
lieu
of
a single channel method. This
will
usuallly be the
case when
a ground loop exists between the scope and the
disk drive. Refer to the applicable oscilloscope manual
for
differential measurement set-up,
if
necessary.
6·53
8300
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