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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:

http://www.lenovo.com/support