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Appendix D. 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: internal and external. External CRUs are easy to install,
whereas internal CRUs require some technical skills and in some cases might require tools such
as a screwdriver. However, both internal and external CRUs are safe for removal by the
customer.
Customers are responsible for replacing all external CRUs. Internal CRUs can be removed and
installed by customers or by a Lenovo service technician during the warranty period.
Your computer contains the following types of external CRUs:
• External CRUs (pluggable): These CRUs unplug from the computer. Examples of these types
of CRUs include the AC adapter and power cord.
• External CRUs with latches: These CRUs include a latch to help you remove and replace the
part. Examples of these types of CRUs include the notebook main battery, an optical drive, a
hard-disk drive, and an extended battery.
Your computer contains the following types of internal CRUs:
• Internal CRUs (located behind an access panel): These CRUs are isolated parts within the
computer that are concealed by an access panel that is typically secured by either one or two
screws. Once the access panel is removed, only the specific CRU is visible. Examples of these
types of CRUs include memory modules and hard disk drives.
• Internal CRUs (located within the product): These CRUs are accessible only by opening the
computer’s outer case. Examples of these CRUs include PCI Express Mini Cards and the
integrated keyboard.