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.
Retaining
serial
numbers
This
section
includes
the
following
descriptions:
v
“Restoring
the
serial
number
of
the
system
unit”
v
“Retaining
the
UUID”
on
page
74
v
“Reading
or
writing
the
ECA
information”
on
page
74
Restoring
the
serial
number
of
the
system
unit
When
the
computer
was
manufactured,
the
EEPROM
on
the
system
board
was
loaded
with
the
serial
numbers
of
the
system
and
all
major
components.
These
numbers
need
to
remain
the
same
throughout
the
life
of
the
computer.
If
you
replace
the
system
board,
you
must
restore
the
serial
number
of
the
system
unit
to
its
original
value.
Before
replacing
the
system
board,
save
the
original
serial
number
by
doing
the
following:
1.
Install
the
ThinkPad
Hardware
Maintenance
Diskette
Version
1.71
or
later,
and
restart
the
computer.
2.
From
the
main
menu,
select
1.
Set
System
Identification
.
3.
Select
2.
Read
S/N
data
from
EEPROM
.
The
serial
number
of
each
device
in
your
computer
is
displayed;
the
serial
number
of
the
system
unit
is
listed
as
follows:
v
20:
Serial
number
Write
down
that
number.
Note:
The
serial
number
of
the
system
unit
is
also
written
on
the
label
attached
to
the
bottom
of
the
computer.
After
you
have
replaced
the
system
board,
restore
the
serial
number
by
doing
the
following:
1.
Install
the
ThinkPad
Hardware
Maintenance
Diskette
Version
1.71
or
later
and
restart
the
computer.
2.
From
the
main
menu,
select
1.
Set
System
Identification
.
3.
Select
1.
Add
S/N
data
from
EEPROM
.
Follow
the
instructions
on
the
screen.
FRU
replacement
notices
ThinkPad
X41
73
