Asus AP1600R-S5 - Manual (Page 22)

22 Chapter 2: Hardware Setup
2.3 Installing and removing the airflow guide
To detach the airflow guide, use a Phillips screwdriver to remove the two
screws that secure the module to the base of the chassis.
To re-install the airflow guide (after installing the CPU and heatsink), place it
on top of the heatsink in the orientation shown above. Secure the airflow
guide using two screws.
The airflow guide comes installed in the system. You have to detach the
airflow guide before you can install a CPU.
Screws
Airflow guide
You also have to remove the PCI riser card and card bracket
assembly before installing a CPU. Refer to section “2.8 Installing
a PCI card” for instructions on how to remove the riser card
assembly.
NOTE