Lenovo ThinkStation 2551, Hardware Maintenance Manual, Page: 81 / 188

• Self-service CRUs: These CRUs unplug or are secured by no more than two screws. Examples of
these types of CRUs include the keyboard, the mouse, any USB device, and the power cord. Other
self-service CRUs depending on product design might include memory modules, adapter cards, hard
disk drives, and optical drives.
• Optional-service CRUs: These CRUs are isolated parts within the computer 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.
Number FRU description
Self-service CRU Optional-service CRU
1
Heat sink and fan assembly No Yes
2
System board No No
3
Microprocessor No No
4
Memory modules Yes No
5
Hard disk drive Yes No
6
Optical drive (available in some models) Yes No
7
Card reader (available in some models) Yes No
8
Front fan assembly No Yes
9
Graphics (PCI) card (available in some models)
Yes No
10
Rear fan assembly No Yes
11
Power supply assembly No Yes
12
Keyboard Yes No
13
Mouse Yes No
Looking up FRU information
For detailed FRU information, such as the FRU part numbers and supported computer models, go to:
http:/www.lenovo.com/serviceparts-lookup
Chapter 9
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