Lenovo ThinkCentre M79 Hardware Maintenance Manual page 41

The following table lists the major FRUs shown in Figure 4 "Component locations" on page 32 and identifies
which FRUs also are self-service CRUs or optional-service CRUs.
Notes:
• 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
1
Power supply assembly
2
Microprocessor
3
Memory module
4
Optical drive (available on some models)
5
Front Wi-Fi antenna (available on some models)
6
Front bezel
7
Front audio and USB assembly
8
Slim card reader (available on some models)
9
Thermal sensor
10
Front fan assembly
11
Hard disk drive
12
Battery
13
System board
14
Wi-Fi card module (available on some models)
15
Wi-Fi adapter card (available on some models)
16
Rear Wi-Fi antenna (available on some models)
17
PCI Express card
18
Heat sink and fan assembly
19
Keyboard
20
Mouse
FRU description
Self-service CRU Optional-service CRU
No
No
Yes
Yes
No
Yes
No
No
No
No
No
Yes
No
No
No
Yes
Yes
No
Yes
Yes
.
Chapter 2
Yes
Yes
No
No
Yes
No
Yes
Yes
Yes
Yes
Yes
No
No
Yes
Yes
No
No
Yes
No
No
33
Product overview