CRUs are computer parts that a user can upgrade or replace. There are two types of CRUs: self-service and optional-service.
You can install self-service CRUs easily. These CRUs might be standalone, latched, or secured by up to two screws.
Examples of self-service CRUs include the keyboard, mouse, any USB device, and the power cord. Other self-service CRUs might include memory modules, adapter cards, hard disk drives, and optical drives.
Note
Users are responsible for replacing all self-service CRUs.
Handling optional-service CRUs requires some technical skills and simple tools (such as a screwdriver).
These CRUs are isolated parts within the computer. They are usually concealed by an access panel that is secured by more than two screws. You must remove the screws and panel to access the specific CRU.
Optional-service CRUs can be removed and installed by users or, during the warranty period, by a Lenovo service technician.
FRUs are computer parts that a trained technician can upgrade or replace.
For detailed FRU information, such as the FRU part numbers and supported computer models, go to:
http:/www.lenovo.com/serviceparts-lookup
Refer to the following illustrations to check the locations of CRUs and FRUs within the computer.
Notes