Asus CUV4X JumperFree PC133 User Manual page 59

For processors with unlocked frequency multiplier
System Hangup
If your system crashes or hangs due to improper frequency settings, power
OFF your system and restart. The system will start up in safe mode running
at a bus speed of 66MHz and enter BIOS setup.
Cause for Hangup: Improper CPU Speed
Cause for Hangup: Improper CPU: System Frequency Multiple
(For processors with unlocked frequency multiplier only)
Cause for Hangup: Improper System/SDRAM Frequency Ratio
4. BIOS SETUP
ASUS CUV4X User's Manual 59