MPI 40 Series - Page 83

102 pages

Save Page as PDF

To Next Page

To Next Page

To Previous Page

To Previous Page

Loading...

E.

Connect

a jumper from

ground

to

gate

U24

pin

6.

F.

Step

back

and

forth

across

track

72

for

about

15

seconds.

G.

At

the

end

of

the

15-second

period,

remove jumper

installed

in

Step

E above and

return

head(s)

to

track

72.

The

ampli-

tude

displayed

on

the

oscilloscope

should

be

reduced

by

at

least

85%

in

some

parts

of

the

trace.

H.

If

the

amplitude

decrease

is

less

than

85%,

refer

to

the

troubleshooting

information

in

section

5.

4.7

.3

High Frequency Playback Measurement

To

measure

the

amount

of

high

frequency

playback,

perform

the

following

steps

in

the

order

listed.

A.

Apply power

to

the

disk

drive

and

select

drive.

B.

Step

the

head(s)

to

track

76.

c.

Write

a

2F

(hex)

pattern

(500

KHz)

on

the

entire

track.

D.

Connect

oscilloscope

to

TP4

and

TP5

as

described

in

radial-

track

alignment

procedure

(refer

to

paragraph

4.6.1).

E. The

peak-to-peak

amplitude

displayed

on

the

oscilloscope

should

be

a minimum

of

230

mv

p-p.

If

the

amplitude

is

less,

refer

to

the

troubleshooting

information

in

section

5.

4-30

Table of Contents