RTFM
2) Cautions During Booting
When booting the computer, it may automatically power down after an alarm sound by a system
monitoring program to indicate that the CPU fan is rotating slowly. If this happens, turn the speed
control knob fully clockwise to increase the fan speed. Then set ‘CPU Fan Detected’ to ‘Disabled’ in
BIOS settings, or set the slowest rotational speed of the CPU fan in the system monitoring program to
less than or equal to 1300rpm.
Note) Some motherboards do not boot if the rotational speed of the CPU fan is below a certain r p m.
If the BIOS settings are updated, Silent Mode can be used. For more information on updating
your BIOS, please refer to your motherboard manufacturer's website. Disabling CPU fan speed
detection in BIOS settings does not affect computer performance.