HP Compaq Presario C542EA Notebook PC - Manual (Page 13)

Rear components
Component Description
Vent* Provides airflow to cool internal components.
CAUTION To prevent overheating, do not obstruct
vents. Use the computer only on a hard, flat surface. Do
not allow another hard surface, such as an adjoining
optional printer, or a soft surface, such as pillows or thick
rugs or clothing, to block airflow.
NOTE The computer fan starts up automatically to cool
internal components and prevent overheating. It is normal
for the internal fan to cycle on and off during routine
operation.
*The computer has 3 vents. The other vents are located on the bottom of the computer.
ENWW Components 7