Chapter 3. customer replaceable units (crus), Chapter, Customer – Lenovo ThinkServer RD210 User Manual
Page 25: Replaceable, Units, Crus)
Chapter
3.
Customer
Replaceable
Units
(CRUs)
Customer
Replaceable
Units
(CRUs)
are
computer
parts
that
can
be
upgraded
or
replaced
by
the
customer.
There
are
two
types
of
CRUs:
Self-service
CRUs
and
Optional-service
CRUs.
Self-service
CRUs
are
easy
to
install.
They
might
be
standalone,
latched,
or
require
a
screwdriver
to
remove
a
maximum
of
two
screws.
However,
Optional-service
CRUs
require
some
technical
skills
and
in
some
cases
might
also
require
simple
tools,
such
as
a
screwdriver.
However,
both
Self-service
and
Optional-service
CRUs
are
safe
for
the
customer
to
remove.
Customers
are
responsible
for
replacing
all
Self-service
CRUs.
Optional-service
CRUs
can
be
removed
and
installed
by
customers
or
by
a
Lenovo
service
technician
during
the
warranty
period.
Lenovo
servers
contain
both
Self-service
and
Optional-service
CRUs.
v
Self-service
CRUs:
These
CRUs
unplug
or
are
secured
by
no
more
than
two
screws.
Examples
of
these
types
of
CRUs
include
any
Universal
Serial
Bus
(USB)
device
and
the
power
cord.
Other
Self-service
CRUs
depending
on
product
design
might
include
hot-swap
hard
disk
drives,
hot-swap
fans,
hot-swap
power
supplies,
dual
inline
memory
modules
(DIMMs),
and
Redundant
Array
of
Independent
Disks
(RAID)
cards.
v
Optional-service
CRUs:
These
CRUs
are
isolated
parts
within
the
server
and
are
concealed
by
an
access
panel
that
is
typically
secured
by
more
than
two
screws.
Once
the
access
panel
is
removed,
the
specific
CRU
is
visible.
One
example
of
an
Optional-service
CRU
is
the
Direct
Access
Storage
Device
(DASD)
backplane.
v
Both
types
of
CRUs
are
listed
in
the
tables
on
the
following
page.
The
Installation
and
User
Guide
provides
instructions
on
how
to
replace
Self-service
CRUs
and
Optional-service
CRUs.
Refer
to
the
following
tables
to
determine
which
publication
contains
the
instructions
you
need.
The
publications
are
available
on
the
ThinkServer
Documentation
DVD
and
also
the
Lenovo
Web
site
at:
©
Lenovo
2009.
Portions
©
IBM
Corp.
2005.
19