HP Pavilion dv7-4278nr Entertainment Notebook PC - Manual (Page 17)

Bottom components
Item Description Function
(1) Battery bay Holds the battery.
(2) Battery Release latch Releases the battery from the battery bay.
(3) Vents (7) Enables airflow to cool internal components.
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.
(4) Primary Hard Drive bay Holds the primary hard drive, the memory module slots, and the
WLAN module (select models only).
CAUTION: To prevent an unresponsive system, replace the
wireless module with a wireless module authorized for use by the
governmental agency that regulates wireless devices in your
country or region. If you replace the module and then receive a
warning message, remove the module to restore computer
functionality, and then contact technical support through Help and
Support.
(5) Integrated subwoofer (select models only) Provides superior bass sound.
Components 7