Asus RS120-E4/PA2 - Manual (Page 34)

Chapter 2: Hardware setup 2-18
2.8 Removable components
You may need to remove previously installed system components when installing
or removing system devices, or when you need to replace defective components.
This section tells how to remove the following components:
1. System fans
2. Device fan
3. Power supply module
4. Optical drive
5. Motherboard
2.8.1 System fans
The system comes with four units of 28 mm x 40 mm 15500 rpm fan with dummy
case. Refer to the illustration below for location of the system fans.
28 mm x 40 mm fan with dummy case
Incorrect installation of the system fan with dummy case may result to CPU
overheating and/or automatic system shutdown.