Asus AP120-E1 - Manual (Page 27)

ASUS P4P800S-E motherboard user guide 2-1
2.1 Motherboard installation
Before you install the motherboard, study the configuration of your chassis
to ensure that the motherboard fits into it. The motherboard uses the ATX
form factor that measures 12 inches x 9.6 inches (30.5 cm x 24.5 cm).
Do not overtighten the screws! Doing so may damage the motherboard.
2.1.1 Placement direction
When installing the motherboard, make sure that you place it into the
chassis in the correct orientation. The edge with external ports goes to the
rear part of the chassis as indicated in the image below.
2.1.2 Screw holes
Place nine (9) screws into the holes indicated by circles to secure the
motherboard to the chassis.
Make sure to unplug the power cord before installing or removing the
motherboard. Failure to do so may cause you physical injury and may damage
motherboard components.
Place this side towards
the rear of the chassis