v
“Retaining
the
UUID”
v
“Reading
or
writing
the
ECA
information”
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
1.73
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
1.73
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.
Retaining
the
UUID
The
Universally
Unique
Identifier
(UUID)
is
a
128-bit
number
uniquely
assigned
to
your
computer
at
production
and
stored
in
the
EEPROM
of
your
system
board.
The
algorithm
that
generates
the
number
is
designed
to
provide
unique
IDs
until
the
year
A.D.
3400.
No
two
computers
in
the
world
have
the
same
number.
When
you
replace
the
system
board,
you
must
set
the
UUID
on
the
new
system
board
as
follows:
1.
Install
the
ThinkPad
Hardware
Maintenance
Diskette
Version
1.73
or
later,
and
restart
the
computer.
2.
From
the
main
menu,
select
4.
Assign
UUID
.
A
new
UUID
is
created
and
written.
If
a
valid
UUID
already
exists,
it
is
not
overwritten.
Reading
or
writing
the
ECA
information
Information
on
Engineering
Change
Announcements
(ECA)
are
stored
in
the
EEPROM
of
the
system
board.
The
electronic
storage
of
this
information
simplifies
the
procedure
to
check
if
the
ECA
has
been
previously
applied
to
a
machine.
The
machine
does
not
need
to
be
disassembled
to
check
for
the
ECA
application.
FRU
replacement
notices
ThinkPad
Z61t
53
Summary of Contents for Z61t
Page 2: ......
Page 3: ...ThinkPad Z61t Hardware Maintenance Manual ...
Page 6: ...iv MT 8747 8749 9440 9441 9442 9443 and 9448 ...
Page 8: ...2 MT 8747 8749 9440 9441 9442 9443 and 9448 ...
Page 68: ...2 3 4 Removing and replacing a FRU 62 MT 8747 8749 9440 9441 9442 9443 and 9448 ...
Page 94: ...5 5 Removing and replacing a FRU 88 MT 8747 8749 9440 9441 9442 9443 and 9448 ...
Page 116: ...3 5 4 6 continued Removing and replacing a FRU 110 MT 8747 8749 9440 9441 9442 9443 and 9448 ...
Page 171: ...Trademarks ThinkPad Z61t 165 ...
