Asus P4PE-X/TE - Manual (Page 40)

2-8 Chapter 2: BIOS information
Award BIOS Beep Codes
Beep Meaning
One short beep when No error during POST
displaying logo
Long beeps in an endless loop No DRAM installed or detected
One long beep followed by Video card not found or video card
three short beeps memory bad
High frequency beeps when CPU overheated;
system is working System running at a lower frequency
2.1.4 BIOS beep codes
When you turn the power on and the system runs POST (Power On Self Tests),
you will hear BIOS beeps. Refer to the following table for the meaning of the
beeps.