HP ProBook 450 G2, Maintenance And Service Manual, Page: 73 / 169

RTC battery, HP 455 models
Description Spare part number
RTC battery 738824-001
Before removing the RTC battery, follow these steps:
On HP 455 models, you access the RTC battery without removing the system board.
1. Shut down the computer. If you are unsure whether the computer is off or in Hibernation, turn the
computer on, and then shut it down through the operating system.
2. Disconnect all external devices connected to the computer.
3. Disconnect the power from the computer by first unplugging the power cord from the AC outlet, and
then unplugging the AC adapter from the computer.
4. Remove the battery (see Battery on page 36 ).
5. Remove the following components:
a. Service doors (see Service door on page 37 ).
b. Hard drive (see Hard drive on page 39 )
c. Optical drive (see Optical drive on page 43 )
d. Keyboard (see Keyboard on page 49 )
e. Top cover (see Top cover on page 58 )
Remove the RTC battery:
1. Using a flat tool, pry the battery out of the socket (1).
2. Remove the battery from the socket (2).
Reverse this procedure to install the RTC battery.
Component replacement procedures 61