Asus AP1720-E2 - Manual (Page 28)

Chapter 2: Hardware setup 2-8
2. Use a Phillips screwdriver to
tighten the four heatsink screws
in a diagonal sequence.
3. Connect the fan cable to the 4-pin
connector labeled CPU_FAN1.
1 3
4 2
CPU1 fan connector
(CPU_FAN1)
To install the CPU heatsink and fan:
1. Place the heatsink on top of the
installed CPU, making sure that
the four screws on the heatsink
align with the screw holes on the
CEK spring.
The CEK springs come pre-installed under the CPU sockets to support
the weight of the CPU heatsinks. It is recommended that you keep the
springs installed to prevent motherboard breakage.