FRU
replacement
notices
This
section
contains
notices
related
to
removing
and
replacing
parts.
Read
this
section
carefully
before
replacing
any
FRU.
Screw
notices
Loose
screws
can
cause
a
reliability
problem.
In
the
Lenovo
3000
computer,
this
problem
is
addressed
with
special
nylon-coated
screws
that
have
the
following
characteristics:
v
They
maintain
tight
connections.
v
They
do
not
easily
come
loose,
even
with
shock
or
vibration.
v
They
are
harder
to
tighten.
v
Each
one
should
be
used
only
once.
Do
the
following
when
you
service
this
machine:
v
Keep
the
screw
kit
(for
the
P/N,
see
“Miscellaneous
parts”
on
page
152)
in
your
tool
bag.
v
Always
use
new
screws.
v
Use
a
torque
screwdriver
if
you
have
one.
Tighten
screws
as
follows:
v
Plastic
to
plastic
Turn
an
additional
90
degrees
after
the
screw
head
touches
the
surface
of
the
plastic
part:
90 degrees more
(Cross-section)
v
Logic
card
to
plastic
Turn
an
additional
180
degrees
after
the
screw
head
touches
the
surface
of
the
logic
card:
180 degrees more
(Cross-section)
v
Torque
driver
If
you
have
a
torque
driver,
refer
to
the
“Torque”
column
for
each
step.
v
Make
sure
that
you
use
the
correct
screw.
If
you
have
a
torque
screwdriver,
tighten
all
screws
firmly
to
the
torque
shown
in
the
table.
Never
use
a
screw
that
you
removed.
Use
a
new
one.
Make
sure
that
all
of
the
screws
are
tightened
firmly.
v
Ensure
torque
screwdrivers
are
calibrated
correctly
following
country
specifications.
Retaining
serial
numbers
This
section
includes
the
following
descriptions:
v
“Restoring
the
serial
number
of
the
system
unit”
on
page
43
FRU
replacement
notices
42
MT
0689,
0768,
and
0769
